admin tools

references:
20 Command Line Tools to Monitor Linux Performance
20 Linux System Monitoring Tools Every SysAdmin Should Know
Top 25 Best Linux Performance Monitoring and Debugging Tools
http://www.thegeekstuff.com/2010/12/50-unix-linux-sysadmin-tutorials
16 commands to check hardware information on Linux
Best UNIX shell-based tools
* alebcay/awesome-shell
* zh-cn
nosarthur/awesome-shell
* rockerBOO/awesome-neovim
jlevy/the-art-of-command-line
Learn Enough Command Line to Be Dangerous
Shell Style Guide
Use Bash Strict Mode (Unless You Love Debugging)
others
bayandin/awesome-awesomeness
emijrp/awesome-awesome
kahun/awesome-sysadmin
My Minimalist Over-powered Linux Setup Guide
* devynspencer/cute_commands.sh

encryption

gpg

[!NOTE|label:references:]
* The GNU Privacy Handbook
* The GNU Privacy Guard Manual
GPG入门教程
GPG(GnuPG)入门
FlowCrypt: PGP Encryption for Gmail

basic knowledge

[!NOTE|label:references:]
to show --dump-options: gpg --dump-options

letters indicating
[!TIP|label:references:]
- 简明 GPG 概念
- GPG 密钥的能力中， [C]、[S]、[A] 均属于签名方案，只有 [E] 是加密方案
- The GNU Privacy Guard Manual : 4.2.1 How to change the configuration
- OpenPGP Message Format : 5.2.3.21. Key Flags
- How are the GPG usage flags defined in the key details listing?
- Anatomy of a GPG Key
LETTER
MEANING
flag
CONSTANT
COMMENTS
[C]
Certification
0x01
PUBKEY_USAGE_CERT
认证其他秘钥/给其他证书签名
[S]
Signing
0x02
PUBKEY_USAGE_SIG
签名,如给文件添加数字签名, 给 git commit 签名
[A]
Authenticate
0x20
PUBKEY_USAGE_AUTH
身份验证, 如 ssh 登录
[E]
Encryption
0x04 or 0x08
PUBKEY_USAGE_ENC
加密, 如给文件加密, 给邮件加密

create new key

[!NOTE|label:references:]
Generating GPG Keys
How to create GPG keypairs
Generating a new GPG key

$ gpg --full-generate-key

$ gpg --batch --gen-key <<EOF
%no-protection
Key-Type:1
Key-Length:2048
Subkey-Type:1
Subkey-Length:2048
Name-Real: <John Doe>
Name-Email: <john.doe@domain.com>
Expire-Date:0
EOF

list keys

secret keys

$ gpg --list-secret-keys --keyid-format=long
gpg: checking the trustdb
gpg: marginals needed: 3  completes needed: 1  trust model: pgp
gpg: depth: 0  valid:   1  signed:   0  trust: 0-, 0q, 0n, 0m, 0f, 1u
[keyboxd]
---------
sec   ed25519/505104FC7CD6CA33 2024-05-08 [SC]
      00D2F41050BF7D9BE6B27545505104FC7CD6CA33
uid                 [ultimate] marslo <marslo.jiao@gmail.com>
ssb   cv25519/188C36434D6B9F66 2024-05-08 [E]

public keys

$ gpg --list-public-keys --keyid-format=long
[keyboxd]
---------
pub   ed25519/5C0980808D968494 2024-05-08 [SC]
      6AADCD68E268DEF623C4DD7E5C0980808D968494
uid                 [ultimate] marslo <marslo.jiao@gmail.com>
sub   cv25519/F065036D0FF76ABA 2024-05-08 [E]

list KEYID

$ gpg --list-keys --with-colons |
      awk -F: '$1 == "pub" && ($2 == "e" || $2 == "r" || $2 == "u") { print $5 }'

with fingerprint

$ gpg --list-secret-keys --with-colons --fingerprint
sec:u:255:22:5C0980808D968494:1715138996:::u:::scESC:::+::ed25519:::0:
fpr:::::::::6AADCD68E268DEF623C4DD7E5C0980808D968494:
grp:::::::::DA2F273B9FCDBCE44E8F5B1590CC29F774C557A5:
uid:u::::1715138996::689D1C164C7C46F315D0FF60C5CDE6E509C6D853::marslo <marslo.jiao@gmail.com>::::::::::0:
ssb:u:255:18:F065036D0FF76ABA:1715138996::::::e:::+::cv25519::
fpr:::::::::B6550514914F4E14976755BBF065036D0FF76ABA:
grp:::::::::C55CD6EE8B06EC939090352069AB9D37CFA0C7FA:

# list fingerprint only
$ gpg --list-keys --with-colons | awk -F: '$1 == "fpr" { print $10 }'
6AADCD68E268DEF623C4DD7E5C0980808D968494
B6550514914F4E14976755BBF065036D0FF76ABA

# or
$ gpg --list-secret-keys --with-colons --fingerprint | sed -n 's/^fpr:::::::::\([[:alnum:]]\+\):/\1/p'
6AADCD68E268DEF623C4DD7E5C0980808D968494
B6550514914F4E14976755BBF065036D0FF76ABA

remove keys

remove all keys

$ gpg --yes --delete-secret-and-public-key "marslo"
gpg (GnuPG) 2.4.5; Copyright (C) 2024 g10 Code GmbH
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.

sec  ed25519/133597088DEF3074 2024-05-08 marslo (marslo) <marslo.jiao@gmail.com>

Delete this key from the keyring? (y/N) y
This is a secret key! - really delete? (y/N) y

pub  ed25519/133597088DEF3074 2024-05-08 marslo (marslo) <marslo.jiao@gmail.com>
Delete this key from the keyring? (y/N) y

or via --batch

$ gpg --list-keys --with-colons \
    | awk -F: '$1 == "pub" && ($2 == "e" || $2 == "r" || $2 == "u") { print $5 }' \
    | xargs gpg --batch --yes --delete-secret-and-public-key

or via fingerprint

$ gpg --fingerprint --with-colons ${GPG_KEY} |\
      grep "^fpr" |\
      sed -n 's/^fpr:::::::::\([[:alnum:]]\+\):/\1/p' |\
      xargs gpg --batch --delete-secret-keys

export/import keys

[!NOTE|label:references:]
How to export a GPG private key and public key to a file
Moving GPG Keys Privately

export

export public key

$ gpg --output public.pgp --armor --export <KEYID>

check content

$ gpg --armor --export <KEYID>

# i.e.:
$ gpg --armor --export marslo
-----BEGIN PGP PUBLIC KEY BLOCK-----
...
-----END PGP PUBLIC KEY BLOCK-----

export secret key

$ gpg --output private.pgp --armor --export-secret-key <KEYID>
# or
$ gpg -o ~/private.asc --export-secret-key <KEYID>

export and ssh

$ gpg --export-secret-key SOMEKEYID | ssh othermachine gpg --import

$ gpg --output public.gpg --export SOMEKEYID && \
$ gpg --output - --export-secret-key SOMEKEYID |\
      cat public.gpg - |\
      gpg --armor --output keys.asc --symmetric --cipher-algo AES256

check content

$ gpg --armor --export-secret-keys <KEYID>

# i.e.:
$ gpg --armor --export-secret-keys marslo
-----BEGIN PGP PRIVATE KEY BLOCK-----
...
-----END PGP PRIVATE KEY BLOCK-----

backup keys

$ gpg --output backupkeys.pgp --armor --export-secret-keys --export-options export-backup <KEYID>
# or
$ gpg --output backupkeys.pgp --armor --export --export-options export-backup <KEYID>

import

[!NOTE|label:references:]
How to import secret keys into GPG keychain
pass and gpg: No public key
How to import secret gpg key (copied from one machine to another)?

# import private key
$ gpg --import private.pgp
gpg: /home/marslo/.gnupg/trustdb.gpg: trustdb created
gpg: key 5C0980808D968494: public key "marslo <marslo.jiao@gmail.com>" imported
gpg: key 5C0980808D968494: secret key imported
gpg: Total number processed: 1
gpg:               imported: 1
gpg:       secret keys read: 1
gpg:   secret keys imported: 1

# list keys
$ gpg --list-keys
/home/marslo/.gnupg/pubring.kbx
-------------------------------
pub   ed25519 2024-05-08 [SC]
      6AADCD68E268DEF623C4DD7E5C0980808D968494
uid           [ unknown] marslo <marslo.jiao@gmail.com>
sub   cv25519 2024-05-08 [E]

# trust
$ gpg --edit-key 6AADCD68E268DEF623C4DD7E5C0980808D968494 trust quit
  1 = I don't know or won't say
  2 = I do NOT trust
  3 = I trust marginally
  4 = I trust fully
  5 = I trust ultimately
  m = back to the main menu

gpg> Your decision? 5
gpg> Do you really want to set this key to ultimate trust? (y/N) y

# check key again
$ gpg --list-keys
gpg: checking the trustdb
gpg: marginals needed: 3  completes needed: 1  trust model: pgp
gpg: depth: 0  valid:   1  signed:   0  trust: 0-, 0q, 0n, 0m, 0f, 1u
/home/marslo/.gnupg/pubring.kbx
-------------------------------
pub   ed25519 2024-05-08 [SC]
      6AADCD68E268DEF623C4DD7E5C0980808D968494
uid           [ultimate] marslo <marslo.jiao@gmail.com>
sub   cv25519 2024-05-08 [E]

import publid key

# import public key
$ gpg --import public.pgp
gpg: key 5C0980808D968494: "marslo <marslo.jiao@gmail.com>" not changed
gpg: Total number processed: 1
gpg:              unchanged: 1

trust key

# verify available
$ gpg --edit-key <KEYID>

# trust
$ gpg --edit-key <KEYID>
gpg> trust
gpg> save
gpg> quit

recover from backup keys

$ gpg --import-options restore --import backupkeys.pgp

usage

[!NOTE|label:references:]
GPG使用方法总结（密钥管理，加解密文件）

pass

[!NOTE]
pass: the standard unix password manager
git repo: password-store
video: How to Use Pass Which Is a Command Line Password Manager
How to Use Pass Which Is a Command Line Password Manager
archlinux: pass
compatible clients
Clever uses of pass, the Unix password manager
Configuring Pass, the Standard Unix Password Manager

env

[!NOTE|label:references:]
completion
environment variable
PASSWORD_STORE_DIR
PASSWORD_STORE_KEY
PASSWORD_STORE_GENERATED_LENGTH
PASSWORD_STORE_CHARACTER_SET
PASSWORD_STORE_CHARACTER_SET_NO_SYMBOLS
PASSWORD_STORE_CLIP_TIME
PASSWORD_STORE_EXTENSIONS_DIR
PASSWORD_STORE_ENABLE_EXTENSIONS
PASSWORD_STORE_SIGNING_KEY

$ export PASSWORD_STORE_DIR=~/.password-store

install

# osx
$ brew install pass

# ubuntu/debian
$ sudo apt-get install pass

# fedora/rhel
$ sudo yum install pass

init
[!TIP|label:references:]
- How to manage Linux passwords with the pass command
- I try to add passwords to the "pass" password manager. But my attempts fail with "no public key" GPG errors. Why?
- to avoid the issue like:
  $ pass generate test 30 gpg: marslo: skipped: No public key gpg: [stdin]: encryption failed: No public key Password encryption aborted.
```
$ gpg --full-generate-key
```

insert

$ pass insert <NAME>

# i.e.:
$ pass insert test
Enter password for test: abc
Retype password for test: abc
$ pass test
abc

# copy
$ pass -c test
Copied test to clipboard. Will clear in 45 seconds.

generate

[!NOTE|label:references:]
PASSWORD_STORE_CHARACTER_SET_NO_SYMBOLS isn't respected
[pass] Provide symbol set as command line argument
How to generate secure passwords using terminal (Mac/Linux) ?
default and envs
PASSWORD_STORE_DIR=$HOME/.password-store
PASSWORD_STORE_EXTENSIONS_DIR=${PASSWORD_STORE_DIR}/.extensions
PASSWORD_STORE_CLIP_TIME=45
PASSWORD_STORE_GENERATED_LENGTH=25
others:
PASSWORD_STORE_CHARACTER_SET='[:alnum:].,!?&*%_~$#^@{}[]()<>|=/\+-'
Vim: word vs WORD

customize charset

$ export PASSWORD_STORE_CHARACTER_SET='a-zA-Z0-9'
$ yes | pass generate test 30
The generated password for test is:
HnD7XyeFDtOrw5oDhn22U8AjHVV9cf
$ yes | pass generate test 30
The generated password for test is:
t57PYCw4r0tHSXCa4zW2DVGNuizQ1k

$ export PASSWORD_STORE_CHARACTER_SET='a-zA-Z0-9()'
$ yes | pass generate test 50
The generated password for test is:
wof1Hw92QXe(G3)MkMRp5Wx3UCMgHIpt)7ENNn(f8r(ZRcztQ1
$ yes | pass generate test 30
The generated password for test is:
60m2XHtqfTsvfJT(YYV1wKlBBoOJYb

generate qrcode
```
$ pass generate <name> --qrcode
```

generate via /dev/urandom

$ head /dev/urandom | tr -dc 'A-Za-z0-9!@#$%^&*()' | head -c 32 && echo
xGPqC%MeE2HU3NkH#JeA##RB^YbX49cd

$ head /dev/urandom | tr -dc 'A-Za-z0-9!@#$%^&*()?:_-~+<=>' | head -c 32 && echo
e?XEGaD68^FNYI5#E^aFVgv:(6_pL>!I

$ head /dev/urandom | tr -dc 'A-Za-z0-9!"#$%&'\''()*+,-./:;<=>?@[\]^_`{|}~' | head -c 32 && echo
+&7<o(zfE[WC30v'D[&RH~;qM-8J>oQC

generate via openssl

$ openssl rand -base64 32
DfXwoBz8UAel09qN1rR97luKy+aFuC8N0Fua+YaSW8A=

# or: https://www.commandlinefu.com/commands/view/24565/generate-a-random-password-30-characters-long
$ openssl rand -rand /dev/urandom -base64 32

remove

$ pass rm test -f
removed '/Users/marslo/.marslo/.password-store/test.gpg'

advanced usage

[!NOTE|label:references:]
extensions
roddhjav/pass-tomb
tadfisher/pass-otp) | pass-otp.bash.completion
roddhjav/pass-import
roddhjav/pass-update
roddhjav/pass-audit
ayushnix/pass-coffin
ayushnix/pass-tessen
additional tools
Pass for Alfred

alfred workflow

$ brew isntall --HEAD pinentry-mac

# using pinentry-mac instead of pinentry for alfred workflow
$ [[ -d "$HOME/.gnupg" ]] || mkdir "$HOME/.gnupg"
$ echo "pinentry-program $(brew --prefix)/bin/pinentry-mac" > $HOME/.gnupg/gpg-agent.conf
$ gpgconf --kill gpg-agent                           # restart the agent

pw() {
  export PASSWORD_STORE_CLIP_TIME=8
  export PASSWORD_STORE_X_SELECTION=primary
  pass -c2 $1; sleep 5; pass -c $1; sleep 5; pass otp -c $1; exit
}

extend

# ~/.bashrc
$ alias passred="PASSWORD_STORE_DIR=~/.pass/red pass"
$ alias passblue="PASSWORD_STORE_DIR=~/.pass/blue pass"

$ cat /usr/share/bash-completion/completions/pass
_passred(){
    PASSWORD_STORE_DIR=~/.pass/red/ _pass
}
complete -o filenames -o nospace -F _passred passred
_passblue(){
    PASSWORD_STORE_DIR=~/.pass/blue/ _pass
}
complete -o filenames -o nospace -F _passblue passblue
$ source /usr/share/bash-completion/completions/pass

git

$ git config --global credential.helper /usr/bin/pass-git-helper

$ cat ~/.gitconfig
[github.com]
target=dev/github

[*.fooo-bar.*]
target=dev/fooo-bar

client

# create local password store
$ pass init <gpg key id>
# enable management of local changes through git
$ pass git init
# add the the remote git repository as 'origin'
$ pass git remote add origin user@server:~/.password-store
# push your local pass history
$ pass git push -u --all

plugins

pass-otp

[!NOTE|label:references:]
#137 Bash completion

# --- install ---
# osx
$ brew install pass-otp
$ brew uses --recursive --installed oath-toolkit
pass-otp

# --- usage ---
## init
$ pass otp insert -e sandbox/otp
Enter otpauth:// URI for sandbox/otp: otpauth://totp/totp-secret?secret=sandbox
## show otp code
$ pass otp sandbox/otp
148395

OTP

[!NOTE|label:references:]
OATH-Toolkit
Use oathtool Linux command line for 2 step verification (2FA)
One-Time-Passwords using oathtool on Ubuntu 14.04(+)

pass-otp

[!NOTE|label:references:]

tips:

$ brew which-formula oathtool
oath-toolkit

$ brew uses --recursive --installed oath-toolkit
pass-otp

$ oathtool $(openssl rand -hex 16)
848050

PGP

[!NOTE|label:references:]
Protecting Code Integrity with PGP
Protecting Code Integrity with PGP — Part 1: Basic Concepts and Tools | 用 PGP 保护代码完整性（一）：基本概念和工具
Protecting Code Integrity with PGP — Part 2: Generating Your Master Key | 用 PGP 保护代码完整性（二）：生成你的主密钥
Protecting Code Integrity with PGP — Part 3: Generating PGP Subkeys | 用 PGP 保护代码完整性（三）：生成 PGP 子密钥
Protecting Code Integrity with PGP — Part 4: Moving Your Master Key to Offline Storage | 用 PGP 保护代码完整性（四）：将主密钥移到离线存储中
Protecting Code Integrity with PGP — Part 5: Moving Subkeys to a Hardware Device | 用 PGP 保护代码完整性（五）：将子密钥移到一个硬件设备中
Protecting Code Integrity with PGP — Part 6: Using PGP with Git | 用 PGP 保护代码完整性（六）：在 Git 上使用 PGP
Protecting Code Integrity with PGP — Part 7: Protecting Online Accounts | 用 PGP 保护代码完整性（七）：保护在线帐户

passwd

[!NOTE|label:references:]
Managing Linux users with the passwd command

network tools

[!NOTE|label:see also:]
iMarslo : linux/network

`vnstat`

$ vnstat -l 1 -i en7
Monitoring en7...    (press CTRL-C to stop)

   rx:     4.10 kbit/s   21.00 KiB          tx:         0 bit/s   6.00 KiB^C

 en7  /  traffic statistics
                           rx         |       tx
--------------------------------------+------------------
  bytes                    21.00 KiB  |        6.00 KiB
--------------------------------------+------------------
          max           53.25 kbit/s  |    12.29 kbit/s
      average           17.20 kbit/s  |     4.92 kbit/s
          min                0 bit/s  |         0 bit/s
--------------------------------------+------------------
  packets                         60  |              52
--------------------------------------+------------------
          max                 15 p/s  |          16 p/s
      average                  6 p/s  |           5 p/s
          min                  2 p/s  |           0 p/s
--------------------------------------+------------------
  time                    10 seconds

`ipcalc`

$ ipcalc 10.25.130.2/23
Address:   10.25.130.2          00001010.00011001.1000001 0.00000010
Netmask:   255.255.254.0 = 23   11111111.11111111.1111111 0.00000000
Wildcard:  0.0.1.255            00000000.00000000.0000000 1.11111111
=>
Network:   10.25.130.0/23       00001010.00011001.1000001 0.00000000
HostMin:   10.25.130.1          00001010.00011001.1000001 0.00000001
HostMax:   10.25.131.254        00001010.00011001.1000001 1.11111110
Broadcast: 10.25.131.255        00001010.00011001.1000001 1.11111111
Hosts/Net: 510                   Class A, Private Internet

$ ipcalc 10.25.131.1/23
Address:   10.25.131.1          00001010.00011001.1000001 1.00000001
Netmask:   255.255.254.0 = 23   11111111.11111111.1111111 0.00000000
Wildcard:  0.0.1.255            00000000.00000000.0000000 1.11111111
=>
Network:   10.25.130.0/23       00001010.00011001.1000001 0.00000000
HostMin:   10.25.130.1          00001010.00011001.1000001 0.00000001
HostMax:   10.25.131.254        00001010.00011001.1000001 1.11111110
Broadcast: 10.25.131.255        00001010.00011001.1000001 1.11111111
Hosts/Net: 510                   Class A, Private Internet

`iostat`

$ iostat
              disk0       cpu    load average
    KB/t  tps  MB/s  us sy id   1m   5m   15m
   19.85   37  0.72   3  1 96  1.78 1.90 1.69

`tcpdump`

[!NOTE|label:references:]
* Tcpdump

$ sudo tcpdump -A -i en7
tcpdump: verbose output suppressed, use -v or -vv for full protocol decode
listening on en7, link-type EN10MB (Ethernet), capture size 262144 bytes
00:33:02.787671 IP 10.25.130.117.53629 > a23-43-240-92.deploy.static.akamaitechnologies.com.https: Flags [.], ack 697481089, win 2048, length 0
E..(....@...
..u.+.\.}..r...)...P...:...
00:33:02.790119 IP 10.25.130.117.51541 > sh-vdc01.mycompany.com.domain: 53089+ PTR? 92.240.43.23.in-addr.arpa. (43)
E..GP....._.
..u
&t..U.5.3...a...........92.240.43.23.in-addr.arpa.....
00:33:02.812866 ARP, Request who-has gw-voice-idf.cdu-cn.mycompany.com tell gw-vg224-idf.cdu-cn.mycompany.com, length 46
....
....
13 packets captured
25 packets received by filter
0 packets dropped by kernel

$ sudo tcpdump -n -i any src or dst target.ip.address [ -v ]

# i.e.
$ sudo tcpdump -n -i any src or dst git.domain.com -v
tcpdump: data link type PKTAP
tcpdump: listening on any, link-type PKTAP (Apple DLT_PKTAP), snapshot length 524288 bytes
00:02:55.698822 IP (tos 0x0, ttl 64, id 0, offset 0, flags [DF], proto TCP (6), length 52)
    10.25.130.104.63447 > 10.69.78.140.29418: Flags [F.], cksum 0x8fe0 (correct), seq 2566890566, ack 4019765769, win 2058, options [nop,nop,TS val 1955309758 ecr 154499413], length 0

`dstat`

strace

[!NOTE|label:references:]
I have a tab completion that hangs, is it possible to use strace to find out what is going on?
Resolve nested aliases to their source commands

$ ... run cmd ...

# or
$ pid=$(echo ??)
$ sudo strace -fp ${pid} -o log

# or
$ sudo -v
$ sudo strace -fp $$ -o log &

# -- more --
$ set -o functrace xtrace
$ PS4=' ${BASH_SOURCE}:$FUNCNAME:$LINENO: '

intercept stdout/stderr of another process

$ strace -ff -e trace=write -e write=1,2 -p SOME_PID

# https://www.commandlinefu.com/commands/view/5450/intercept-stdoutstderr-of-another-process
$ strace -ff -e write=1,2 -s 1024 -p PID 2>&1 | grep "^ |" | cut -c11-60 | sed -e 's/ //g' | xxd -r -p

# https://www.commandlinefu.com/commands/view/6743/intercept-stdoutstderr-of-another-process-or-disowned-process
$ strace -e write=1,2 -p $PID 2>&1 | sed -un "/^ |/p" | sed -ue "s/^.\{9\}\(.\{50\}\).\+/\1/g" -e 's/ //g' | xxd -r -p

debug script

$ strace -e clone,execve,pipe,dup2 \
         -f bash -c 'cat <(/bin/true) <(/bin/false) <(/bin/echo)'
execve("/usr/bin/bash", ["bash", "-c", "cat <(/bin/true) <(/bin/false) <"...], 0x7fff9b9c6f98 /* 75 vars */) = 0
pipe([3, 4])                            = 0
dup2(3, 63)                             = 63
clone(child_stack=NULL, flags=CLONE_CHILD_CLEARTID|CLONE_CHILD_SETTID|SIGCHLD, child_tidptr=0x7f7cf6a8ca10) = 289963
strace: Process 289963 attached
[pid 289962] pipe([3, 4])               = 0
[pid 289962] dup2(3, 62)                = 62
[pid 289962] clone(child_stack=NULL, flags=CLONE_CHILD_CLEARTID|CLONE_CHILD_SETTID|SIGCHLD <unfinished ...>
[pid 289963] dup2(4, 1)                 = 1
[pid 289962] <... clone resumed>, child_tidptr=0x7f7cf6a8ca10) = 289964
strace: Process 289964 attached
[pid 289963] clone(child_stack=NULL, flags=CLONE_CHILD_CLEARTID|CLONE_CHILD_SETTID|SIGCHLD <unfinished ...>
[pid 289962] pipe([3, 4])               = 0
strace: Process 289965 attached
[pid 289963] <... clone resumed>, child_tidptr=0x7f7cf6a8ca10) = 289965
[pid 289962] dup2(3, 61)                = 61
[pid 289962] clone(child_stack=NULL, flags=CLONE_CHILD_CLEARTID|CLONE_CHILD_SETTID|SIGCHLD <unfinished ...>
[pid 289964] dup2(4, 1)                 = 1
[pid 289965] execve("/bin/true", ["/bin/true"], 0x55ec7c007680 /* 73 vars */strace: Process 289966 attached
 <unfinished ...>
[pid 289962] <... clone resumed>, child_tidptr=0x7f7cf6a8ca10) = 289966
[pid 289964] clone(child_stack=NULL, flags=CLONE_CHILD_CLEARTID|CLONE_CHILD_SETTID|SIGCHLD <unfinished ...>
[pid 289965] <... execve resumed>)      = 0
strace: Process 289967 attached
[pid 289964] <... clone resumed>, child_tidptr=0x7f7cf6a8ca10) = 289967
[pid 289966] dup2(4, 1)                 = 1
[pid 289967] execve("/bin/false", ["/bin/false"], 0x55ec7c007af0 /* 73 vars */ <unfinished ...>
[pid 289966] clone(child_stack=NULL, flags=CLONE_CHILD_CLEARTID|CLONE_CHILD_SETTID|SIGCHLD, child_tidptr=0x7f7cf6a8ca10) = 289968
[pid 289967] <... execve resumed>)      = 0
strace: Process 289968 attached
[pid 289962] execve("/usr/bin/cat", ["cat", "/dev/fd/63", "/dev/fd/62", "/dev/fd/61"], 0x55ec7c007bc0 /* 73 vars */ <unfinished ...>
[pid 289968] execve("/bin/echo", ["/bin/echo"], 0x55ec7c007e20 /* 73 vars */ <unfinished ...>
[pid 289962] <... execve resumed>)      = 0
[pid 289968] <... execve resumed>)      = 0
[pid 289965] +++ exited with 0 +++
[pid 289963] --- SIGCHLD {si_signo=SIGCHLD, si_code=CLD_EXITED, si_pid=289965, si_uid=10564, si_status=0, si_utime=0, si_stime=0} ---
[pid 289963] +++ exited with 0 +++
[pid 289962] --- SIGCHLD {si_signo=SIGCHLD, si_code=CLD_EXITED, si_pid=289963, si_uid=10564, si_status=0, si_utime=0, si_stime=0} ---
[pid 289967] +++ exited with 1 +++
[pid 289964] --- SIGCHLD {si_signo=SIGCHLD, si_code=CLD_EXITED, si_pid=289967, si_uid=10564, si_status=1, si_utime=0, si_stime=0} ---
[pid 289964] +++ exited with 1 +++
[pid 289962] --- SIGCHLD {si_signo=SIGCHLD, si_code=CLD_EXITED, si_pid=289964, si_uid=10564, si_status=1, si_utime=0, si_stime=0} ---

[pid 289968] +++ exited with 0 +++
[pid 289966] --- SIGCHLD {si_signo=SIGCHLD, si_code=CLD_EXITED, si_pid=289968, si_uid=10564, si_status=0, si_utime=0, si_stime=0} ---
[pid 289966] +++ exited with 0 +++
--- SIGCHLD {si_signo=SIGCHLD, si_code=CLD_EXITED, si_pid=289966, si_uid=10564, si_status=0, si_utime=0, si_stime=0} ---
+++ exited with 0 +++

xtrace

xtrace() {
  local eval_cmd
  printf -v eval_cmd '%q' "${@}"
  { set -x
    eval "${eval_cmd}"
  } 2>&1 | grep '^++'
  return "${PIPESTATUS[0]}"
}

`dtruss`

[!TIP|label:references:]
the MacOS alternatives strace
Using modified dtruss.sh

$ sudo dtruss <cmd>

$ sudo dtruss ls
dtrace: system integrity protection is on, some features will not be available

SYSCALL(args)      = return
README.md   artifactory  devops   jenkins  osx    screenshot  vim
SUMMARY.md  cheatsheet   english  linux    programming  tools     virtualization
munmap(0x1155AB000, 0xA0000)     = 0 0
munmap(0x11564B000, 0x8000)    = 0 0
munmap(0x115653000, 0x4000)    = 0 0
munmap(0x115657000, 0x4000)    = 0 0
munmap(0x11565B000, 0x58000)     = 0 0
fsgetpath(0x7FF7BA418580, 0x400, 0x7FF7BA418568)     = 40 0
fsgetpath(0x7FF7BA418580, 0x400, 0x7FF7BA418568)     = 14 0
csrctl(0x0, 0x7FF7BA41898C, 0x4)     = -1 1
__mac_syscall(0x7FF819AD4E1B, 0x2, 0x7FF7BA4187F0)     = 0 0
csrctl(0x0, 0x7FF7BA41899C, 0x4)     = -1 1
__mac_syscall(0x7FF819AD1DA4, 0x5A, 0x7FF7BA418930)    = 0 0
dtrace: error on enabled probe ID 1741 (ID 573: syscall::sysctl:return): invalid kernel access in action #10 at DIF offset 28
dtrace: error on enabled probe ID 1741 (ID 573: syscall::sysctl:return): invalid kernel access in action #10 at DIF offset 28
dtrace: error on enabled probe ID 1741 (ID 573: syscall::sysctl:return): invalid kernel access in action #10 at DIF offset 28
dtrace: error on enabled probe ID 1741 (ID 573: syscall::sysctl:return): invalid kernel access in action #10 at DIF offset 28
open("/\0", 0x20100000, 0x0)     = 3 0
openat(0x3, "System/Cryptexes/OS\0", 0x100000, 0x0)    = 4 0
dup(0x4, 0x0, 0x0)     = 5 0
fstatat64(0x4, 0x7FF7BA4176D1, 0x7FF7BA417AD0)     = 0 0
openat(0x4, "System/Library/dyld/\0", 0x100000, 0x0)     = 6 0
fcntl(0x6, 0x32, 0x7FF7BA417760)     = 0 0
dup(0x6, 0x0, 0x0)     = 7 0
dup(0x5, 0x0, 0x0)     = 8 0
close(0x3)     = 0 0
close(0x5)     = 0 0
close(0x4)     = 0 0
close(0x6)     = 0 0
shared_region_check_np(0x7FF7BA418048, 0x0, 0x0)     = 0 0
fsgetpath(0x7FF7BA4185B0, 0x400, 0x7FF7BA4184E8)     = 83 0
fcntl(0x8, 0x32, 0x7FF7BA4185B0)     = 0 0
close(0x8)     = 0 0
close(0x7)     = 0 0
getfsstat64(0x0, 0x0, 0x2)     = 9 0
getfsstat64(0x106102040, 0x4C38, 0x2)    = 9 0
getattrlist("/\0", 0x7FF7BA4184F0, 0x7FF7BA418460)     = 0 0
stat64("/System/Volumes/Preboot/Cryptexes/OS/System/Library/dyld/dyld_shared_cache_x86_64h\0", 0x7FF7BA418828, 0x0)    = 0 0
dtrace: error on enabled probe ID 1690 (ID 845: syscall::stat64:return): invalid address (0x0) in action #11 at DIF offset 12
stat64("/usr/local/Cellar/coreutils/9.4/bin/gls\0", 0x7FF7BA417CC0, 0x0)     = 0 0
open("/usr/local/Cellar/coreutils/9.4/bin/gls\0", 0x0, 0x0)    = 3 0
mmap(0x0, 0x33358, 0x1, 0x40002, 0x3, 0x0)     = 0x105B18000 0
fcntl(0x3, 0x32, 0x7FF7BA417DD0)     = 0 0
close(0x3)     = 0 0
munmap(0x105B18000, 0x33358)     = 0 0
stat64("/usr/local/Cellar/coreutils/9.4/bin/gls\0", 0x7FF7BA418220, 0x0)     = 0 0
stat64("/usr/lib/libSystem.B.dylib\0", 0x7FF7BA417230, 0x0)    = -1 2
stat64("/System/Volumes/Preboot/Cryptexes/OS/usr/lib/libSystem.B.dylib\0", 0x7FF7BA4171E0, 0x0)    = -1 2
stat64("/usr/lib/libSystem.B.dylib\0", 0x7FF7BA417230, 0x0)    = -1 2
stat64("/usr/lib/libobjc.A.dylib\0", 0x7FF7BA414E80, 0x0)    = -1 2
stat64("/System/Volumes/Preboot/Cryptexes/OS/usr/lib/libobjc.A.dylib\0", 0x7FF7BA414E30, 0x0)    = -1 2
stat64("/usr/lib/libobjc.A.dylib\0", 0x7FF7BA414E80, 0x0)    = -1 2
stat64("/usr/lib/system/libsystem_blocks.dylib\0", 0x7FF7BA414E80, 0x0)    = -1 2
stat64("/System/Volumes/Preboot/Cryptexes/OS/usr/lib/system/libsystem_blocks.dylib\0", 0x7FF7BA414E20, 0x0)    = -1 2
stat64("/usr/lib/system/libsystem_blocks.dylib\0", 0x7FF7BA414E80, 0x0)    = -1 2
stat64("/usr/lib/system/libxpc.dylib\0", 0x7FF7BA414E80, 0x0)    = -1 2
stat64("/System/Volumes/Preboot/Cryptexes/OS/usr/lib/system/libxpc.dylib\0", 0x7FF7BA414E30, 0x0)  = -1 2
stat64("/usr/lib/system/libxpc.dylib\0", 0x7FF7BA414E80, 0x0)    = -1 2
stat64("/usr/lib/system/libsystem_trace.dylib\0", 0x7FF7BA414E80, 0x0)     = -1 2
stat64("/System/Volumes/Preboot/Cryptexes/OS/usr/lib/system/libsystem_trace.dylib\0", 0x7FF7BA414E20, 0x0)     = -1 2
stat64("/usr/lib/system/libsystem_trace.dylib\0", 0x7FF7BA414E80, 0x0)     = -1 2
stat64("/usr/lib/system/libcorecrypto.dylib\0", 0x7FF7BA414E80, 0x0)     = -1 2
stat64("/System/Volumes/Preboot/Cryptexes/OS/usr/lib/system/libcorecrypto.dylib\0", 0x7FF7BA414E30, 0x0) = -1 2
stat64("/usr/lib/system/libcorecrypto.dylib\0", 0x7FF7BA414E80, 0x0)     = -1 2
stat64("/usr/lib/system/libsystem_malloc.dylib\0", 0x7FF7BA414E80, 0x0)    = -1 2
stat64("/System/Volumes/Preboot/Cryptexes/OS/usr/lib/system/libsystem_malloc.dylib\0", 0x7FF7BA414E20, 0x0)    = -1 2
stat64("/usr/lib/system/libsystem_malloc.dylib\0", 0x7FF7BA414E80, 0x0)    = -1 2
stat64("/usr/lib/system/libdispatch.dylib\0", 0x7FF7BA414E80, 0x0)     = -1 2
stat64("/System/Volumes/Preboot/Cryptexes/OS/usr/lib/system/libdispatch.dylib\0", 0x7FF7BA414E30, 0x0)   = -1 2
stat64("/usr/lib/system/libdispatch.dylib\0", 0x7FF7BA414E80, 0x0)     = -1 2
stat64("/usr/lib/system/libsystem_featureflags.dylib\0", 0x7FF7BA414E80, 0x0)    = -1 2
stat64("/System/Volumes/Preboot/Cryptexes/OS/usr/lib/system/libsystem_featureflags.dylib\0", 0x7FF7BA414E20, 0x0)    = -1 2
stat64("/usr/lib/system/libsystem_featureflags.dylib\0", 0x7FF7BA414E80, 0x0)    = -1 2
stat64("/usr/lib/system/libsystem_c.dylib\0", 0x7FF7BA414E80, 0x0)     = -1 2
stat64("/System/Volumes/Preboot/Cryptexes/OS/usr/lib/system/libsystem_c.dylib\0", 0x7FF7BA414E30, 0x0)   = -1 2
stat64("/usr/lib/system/libsystem_c.dylib\0", 0x7FF7BA414E80, 0x0)     = -1 2
stat64("/usr/lib/libc++.1.dylib\0", 0x7FF7BA414E80, 0x0)     = -1 2
stat64("/System/Volumes/Preboot/Cryptexes/OS/usr/lib/libc++.1.dylib\0", 0x7FF7BA414E30, 0x0)     = -1 2
stat64("/usr/lib/libc++.1.dylib\0", 0x7FF7BA414E80, 0x0)     = -1 2
stat64("/usr/lib/libc++abi.dylib\0", 0x7FF7BA414E80, 0x0)    = -1 2
stat64("/System/Volumes/Preboot/Cryptexes/OS/usr/lib/libc++abi.dylib\0", 0x7FF7BA414E30, 0x0)    = -1 2
stat64("/usr/lib/libc++abi.dylib\0", 0x7FF7BA414E80, 0x0)    = -1 2
stat64("/usr/lib/system/libdyld.dylib\0", 0x7FF7BA414E80, 0x0)     = -1 2
stat64("/System/Volumes/Preboot/Cryptexes/OS/usr/lib/system/libdyld.dylib\0", 0x7FF7BA414E30, 0x0)   = -1 2
stat64("/usr/lib/system/libdyld.dylib\0", 0x7FF7BA414E80, 0x0)     = -1 2
stat64("/usr/lib/system/libsystem_info.dylib\0", 0x7FF7BA414E80, 0x0)    = -1 2
stat64("/System/Volumes/Preboot/Cryptexes/OS/usr/lib/system/libsystem_info.dylib\0", 0x7FF7BA414E30, 0x0)    = -1 2
stat64("/usr/lib/system/libsystem_info.dylib\0", 0x7FF7BA414E80, 0x0)    = -1 2
stat64("/usr/lib/system/libsystem_darwin.dylib\0", 0x7FF7BA414E80, 0x0)    = -1 2
stat64("/System/Volumes/Preboot/Cryptexes/OS/usr/lib/system/libsystem_darwin.dylib\0", 0x7FF7BA414E20, 0x0)    = -1 2
stat64("/usr/lib/system/libsystem_darwin.dylib\0", 0x7FF7BA414E80, 0x0)    = -1 2
stat64("/usr/lib/system/libsystem_notify.dylib\0", 0x7FF7BA414E80, 0x0)    = -1 2
stat64("/System/Volumes/Preboot/Cryptexes/OS/usr/lib/system/libsystem_notify.dylib\0", 0x7FF7BA414E20, 0x0)    = -1 2
stat64("/usr/lib/system/libsystem_notify.dylib\0", 0x7FF7BA414E80, 0x0)    = -1 2
stat64("/usr/lib/system/libsystem_networkextension.dylib\0", 0x7FF7BA414E80, 0x0)    = -1 2
stat64("/System/Volumes/Preboot/Cryptexes/OS/usr/lib/system/libsystem_networkextension.dylib\0", 0x7FF7BA414E20, 0x0)    = -1 2
stat64("/usr/lib/system/libsystem_networkextension.dylib\0", 0x7FF7BA414E80, 0x0)    = -1 2
stat64("/usr/lib/system/libsystem_asl.dylib\0", 0x7FF7BA414E80, 0x0)     = -1 2
stat64("/System/Volumes/Preboot/Cryptexes/OS/usr/lib/system/libsystem_asl.dylib\0", 0x7FF7BA414E30, 0x0) = -1 2
stat64("/usr/lib/system/libsystem_asl.dylib\0", 0x7FF7BA414E80, 0x0)     = -1 2
stat64("/usr/lib/system/libsystem_symptoms.dylib\0", 0x7FF7BA414E80, 0x0)    = -1 2
stat64("/System/Volumes/Preboot/Cryptexes/OS/usr/lib/system/libsystem_symptoms.dylib\0", 0x7FF7BA414E20, 0x0)    = -1 2
stat64("/usr/lib/system/libsystem_symptoms.dylib\0", 0x7FF7BA414E80, 0x0)    = -1 2
stat64("/usr/lib/system/libsystem_containermanager.dylib\0", 0x7FF7BA414E80, 0x0)    = -1 2
stat64("/System/Volumes/Preboot/Cryptexes/OS/usr/lib/system/libsystem_containermanager.dylib\0", 0x7FF7BA414E20, 0x0)    = -1 2
stat64("/usr/lib/system/libsystem_containermanager.dylib\0", 0x7FF7BA414E80, 0x0)    = -1 2
stat64("/usr/lib/system/libsystem_configuration.dylib\0", 0x7FF7BA414E80, 0x0)     = -1 2
stat64("/System/Volumes/Preboot/Cryptexes/OS/usr/lib/system/libsystem_configuration.dylib\0", 0x7FF7BA414E20, 0x0)     = -1 2
stat64("/usr/lib/system/libsystem_configuration.dylib\0", 0x7FF7BA414E80, 0x0)     = -1 2
stat64("/usr/lib/system/libsystem_sandbox.dylib\0", 0x7FF7BA414E80, 0x0)     = -1 2
stat64("/System/Volumes/Preboot/Cryptexes/OS/usr/lib/system/libsystem_sandbox.dylib\0", 0x7FF7BA414E20, 0x0)     = -1 2
stat64("/usr/lib/system/libsystem_sandbox.dylib\0", 0x7FF7BA414E80, 0x0)     = -1 2
stat64("/usr/lib/system/libquarantine.dylib\0", 0x7FF7BA414E80, 0x0)     = -1 2
stat64("/System/Volumes/Preboot/Cryptexes/OS/usr/lib/system/libquarantine.dylib\0", 0x7FF7BA414E30, 0x0) = -1 2
stat64("/usr/lib/system/libquarantine.dylib\0", 0x7FF7BA414E80, 0x0)     = -1 2
stat64("/usr/lib/system/libsystem_coreservices.dylib\0", 0x7FF7BA414E80, 0x0)    = -1 2
stat64("/System/Volumes/Preboot/Cryptexes/OS/usr/lib/system/libsystem_coreservices.dylib\0", 0x7FF7BA414E20, 0x0)    = -1 2
stat64("/usr/lib/system/libsystem_coreservices.dylib\0", 0x7FF7BA414E80, 0x0)    = -1 2
stat64("/usr/lib/system/libsystem_m.dylib\0", 0x7FF7BA414E80, 0x0)     = -1 2
stat64("/System/Volumes/Preboot/Cryptexes/OS/usr/lib/system/libsystem_m.dylib\0", 0x7FF7BA414E30, 0x0)   = -1 2
stat64("/usr/lib/system/libsystem_m.dylib\0", 0x7FF7BA414E80, 0x0)     = -1 2
stat64("/usr/lib/system/libmacho.dylib\0", 0x7FF7BA414E80, 0x0)    = -1 2
stat64("/System/Volumes/Preboot/Cryptexes/OS/usr/lib/system/libmacho.dylib\0", 0x7FF7BA414E30, 0x0)  = -1 2
stat64("/usr/lib/system/libmacho.dylib\0", 0x7FF7BA414E80, 0x0)    = -1 2
stat64("/usr/lib/system/libcommonCrypto.dylib\0", 0x7FF7BA414E80, 0x0)     = -1 2
stat64("/System/Volumes/Preboot/Cryptexes/OS/usr/lib/system/libcommonCrypto.dylib\0", 0x7FF7BA414E20, 0x0)     = -1 2
stat64("/usr/lib/system/libcommonCrypto.dylib\0", 0x7FF7BA414E80, 0x0)     = -1 2
stat64("/usr/lib/system/libunwind.dylib\0", 0x7FF7BA414E80, 0x0)     = -1 2
stat64("/System/Volumes/Preboot/Cryptexes/OS/usr/lib/system/libunwind.dylib\0", 0x7FF7BA414E30, 0x0)   = -1 2
stat64("/usr/lib/system/libunwind.dylib\0", 0x7FF7BA414E80, 0x0)     = -1 2
stat64("/usr/lib/liboah.dylib\0", 0x7FF7BA414E80, 0x0)     = -1 2
stat64("/System/Volumes/Preboot/Cryptexes/OS/usr/lib/liboah.dylib\0", 0x7FF7BA414E30, 0x0)     = -1 2
stat64("/usr/lib/liboah.dylib\0", 0x7FF7BA414E80, 0x0)     = -1 2
stat64("/usr/lib/system/libcopyfile.dylib\0", 0x7FF7BA414E80, 0x0)     = -1 2
stat64("/System/Volumes/Preboot/Cryptexes/OS/usr/lib/system/libcopyfile.dylib\0", 0x7FF7BA414E30, 0x0)   = -1 2
stat64("/usr/lib/system/libcopyfile.dylib\0", 0x7FF7BA414E80, 0x0)     = -1 2
stat64("/usr/lib/system/libcompiler_rt.dylib\0", 0x7FF7BA414E80, 0x0)    = -1 2
stat64("/System/Volumes/Preboot/Cryptexes/OS/usr/lib/system/libcompiler_rt.dylib\0", 0x7FF7BA414E30, 0x0)    = -1 2
stat64("/usr/lib/system/libcompiler_rt.dylib\0", 0x7FF7BA414E80, 0x0)    = -1 2
stat64("/usr/lib/system/libsystem_collections.dylib\0", 0x7FF7BA414E80, 0x0)     = -1 2
stat64("/System/Volumes/Preboot/Cryptexes/OS/usr/lib/system/libsystem_collections.dylib\0", 0x7FF7BA414E20, 0x0)     = -1 2
stat64("/usr/lib/system/libsystem_collections.dylib\0", 0x7FF7BA414E80, 0x0)     = -1 2
stat64("/usr/lib/system/libsystem_secinit.dylib\0", 0x7FF7BA414E80, 0x0)     = -1 2
stat64("/System/Volumes/Preboot/Cryptexes/OS/usr/lib/system/libsystem_secinit.dylib\0", 0x7FF7BA414E20, 0x0)     = -1 2
stat64("/usr/lib/system/libsystem_secinit.dylib\0", 0x7FF7BA414E80, 0x0)     = -1 2
stat64("/usr/lib/system/libremovefile.dylib\0", 0x7FF7BA414E80, 0x0)     = -1 2
stat64("/System/Volumes/Preboot/Cryptexes/OS/usr/lib/system/libremovefile.dylib\0", 0x7FF7BA414E30, 0x0) = -1 2
stat64("/usr/lib/system/libremovefile.dylib\0", 0x7FF7BA414E80, 0x0)     = -1 2
stat64("/usr/lib/system/libkeymgr.dylib\0", 0x7FF7BA414E80, 0x0)     = -1 2
stat64("/System/Volumes/Preboot/Cryptexes/OS/usr/lib/system/libkeymgr.dylib\0", 0x7FF7BA414E30, 0x0)   = -1 2
stat64("/usr/lib/system/libkeymgr.dylib\0", 0x7FF7BA414E80, 0x0)     = -1 2
stat64("/usr/lib/system/libsystem_dnssd.dylib\0", 0x7FF7BA414E80, 0x0)     = -1 2
stat64("/System/Volumes/Preboot/Cryptexes/OS/usr/lib/system/libsystem_dnssd.dylib\0", 0x7FF7BA414E20, 0x0)     = -1 2
stat64("/usr/lib/system/libsystem_dnssd.dylib\0", 0x7FF7BA414E80, 0x0)     = -1 2
stat64("/usr/lib/system/libcache.dylib\0", 0x7FF7BA414E80, 0x0)    = -1 2
stat64("/System/Volumes/Preboot/Cryptexes/OS/usr/lib/system/libcache.dylib\0", 0x7FF7BA414E30, 0x0)  = -1 2
stat64("/usr/lib/system/libcache.dylib\0", 0x7FF7BA414E80, 0x0)    = -1 2
stat64("/usr/lib/libSystem.B.dylib\0", 0x7FF7BA414E80, 0x0)    = -1 2
stat64("/System/Volumes/Preboot/Cryptexes/OS/usr/lib/libSystem.B.dylib\0", 0x7FF7BA414E30, 0x0)    = -1 2
stat64("/usr/lib/libSystem.B.dylib\0", 0x7FF7BA414E80, 0x0)    = -1 2
stat64("/usr/lib/system/libsystem_darwindirectory.dylib\0", 0x7FF7BA414E80, 0x0)     = -1 2
stat64("/System/Volumes/Preboot/Cryptexes/OS/usr/lib/system/libsystem_darwindirectory.dylib\0", 0x7FF7BA414E20, 0x0)     = -1 2
stat64("/usr/lib/system/libsystem_darwindirectory.dylib\0", 0x7FF7BA414E80, 0x0)     = -1 2
open("/dev/dtracehelper\0", 0x2, 0x0)    = 3 0
ioctl(0x3, 0x80086804, 0x7FF7BA416E18)     = 0 0
close(0x3)     = 0 0
open("/usr/local/Cellar/coreutils/9.4/bin/gls\0", 0x0, 0x0)    = 3 0
__mac_syscall(0x7FF819AD4E1B, 0x2, 0x7FF7BA4163D0)     = 0 0
map_with_linking_np(0x7FF7BA415FB0, 0x1, 0x7FF7BA415FE0)     = -1 22
close(0x3)     = 0 0
mprotect(0x105B08000, 0x4000, 0x1)     = 0 0
shared_region_check_np(0xFFFFFFFFFFFFFFFF, 0x0, 0x0)     = 0 0
mprotect(0x106100000, 0x40000, 0x1)    = 0 0
access("/AppleInternal/XBS/.isChrooted\0", 0x0, 0x0)     = -1 2
bsdthread_register(0x7FF819DC9B9C, 0x7FF819DC9B88, 0x2000)     = 1073742303 0
getpid(0x0, 0x0, 0x0)    = 49682 0
shm_open(0x7FF819C6CF42, 0x0, 0x19C6B388)    = 3 0
fstat64(0x3, 0x7FF7BA417340, 0x0)    = 0 0
mmap(0x0, 0x4000, 0x1, 0x40001, 0x3, 0x0)    = 0x105B1A000 0
close(0x3)     = 0 0
ioctl(0x2, 0x4004667A, 0x7FF7BA417404)     = 0 0
mprotect(0x105B23000, 0x1000, 0x0)     = 0 0
mprotect(0x105B2D000, 0x1000, 0x0)     = 0 0
mprotect(0x105B2E000, 0x1000, 0x0)     = 0 0
mprotect(0x105B38000, 0x1000, 0x0)     = 0 0
mprotect(0x105B1E000, 0x98, 0x1)     = 0 0
mprotect(0x105B1E000, 0x98, 0x3)     = 0 0
mprotect(0x105B1E000, 0x98, 0x1)     = 0 0
mprotect(0x105B39000, 0x1000, 0x1)     = 0 0
mprotect(0x105B3A000, 0x98, 0x1)     = 0 0
mprotect(0x105B3A000, 0x98, 0x3)     = 0 0
mprotect(0x105B3A000, 0x98, 0x1)     = 0 0
mprotect(0x105B1E000, 0x98, 0x3)     = 0 0
mprotect(0x105B1E000, 0x98, 0x1)     = 0 0
mprotect(0x105B39000, 0x1000, 0x3)     = 0 0
mprotect(0x105B39000, 0x1000, 0x1)     = 0 0
mprotect(0x106100000, 0x40000, 0x3)    = 0 0
mprotect(0x106100000, 0x40000, 0x1)    = 0 0
issetugid(0x0, 0x0, 0x0)     = 0 0
mprotect(0x106100000, 0x40000, 0x3)    = 0 0
getentropy(0x7FF7BA416C30, 0x20, 0x0)    = 0 0
mprotect(0x106100000, 0x40000, 0x1)    = 0 0
mprotect(0x106100000, 0x40000, 0x3)    = 0 0
mprotect(0x106100000, 0x40000, 0x1)    = 0 0
getattrlist("/usr/local/opt/coreutils/libexec/gnubin/ls\0", 0x7FF7BA4172E0, 0x7FF7BA4172F8)    = 0 0
access("/usr/local/Cellar/coreutils/9.4/bin\0", 0x4, 0x0)    = 0 0
open("/usr/local/Cellar/coreutils/9.4/bin\0", 0x0, 0x0)    = 3 0
fstat64(0x3, 0x7FAEECF042E0, 0x0)    = 0 0
csrctl(0x0, 0x7FF7BA41753C, 0x4)     = 0 0
fcntl(0x3, 0x32, 0x7FF7BA4171F0)     = 0 0
close(0x3)     = 0 0
open("/usr/local/Cellar/coreutils/9.4/bin/Info.plist\0", 0x0, 0x0)     = -1 2
proc_info(0x2, 0xC212, 0xD)    = 64 0
csops_audittoken(0xC212, 0x10, 0x7FF7BA417540)     = -1 22
dtrace: error on enabled probe ID 1741 (ID 573: syscall::sysctl:return): invalid kernel access in action #10 at DIF offset 28
dtrace: error on enabled probe ID 1741 (ID 573: syscall::sysctl:return): invalid kernel access in action #10 at DIF offset 28
csops(0xC212, 0x0, 0x7FF7BA4179A4)     = 0 0
mprotect(0x106100000, 0x40000, 0x3)    = 0 0
open_nocancel("/usr/share/locale/en_US.UTF-8/LC_COLLATE\0", 0x0, 0x0)    = 3 0
fcntl_nocancel(0x3, 0x3, 0x0)    = 0 0
getrlimit(0x1008, 0x7FF7BA417D10, 0x0)     = 0 0
fstat64(0x3, 0x7FF7BA417C88, 0x0)    = 0 0
dtrace: error on enabled probe ID 1714 (ID 961: syscall::read_nocancel:return): invalid kernel access in action #12 at DIF offset 68
close_nocancel(0x3)    = 0 0
open_nocancel("/usr/share/locale/en_US.UTF-8/LC_CTYPE\0", 0x0, 0x0)    = 3 0
fcntl_nocancel(0x3, 0x3, 0x0)    = 0 0
fstat64(0x3, 0x7FF7BA417DD0, 0x0)    = 0 0
fstat64(0x3, 0x7FF7BA417BD8, 0x0)    = 0 0
lseek(0x3, 0x0, 0x1)     = 0 0
lseek(0x3, 0x0, 0x0)     = 0 0
dtrace: error on enabled probe ID 1714 (ID 961: syscall::read_nocancel:return): invalid kernel access in action #12 at DIF offset 68
dtrace: error on enabled probe ID 1714 (ID 961: syscall::read_nocancel:return): invalid kernel access in action #12 at DIF offset 68
dtrace: error on enabled probe ID 1714 (ID 961: syscall::read_nocancel:return): invalid kernel access in action #12 at DIF offset 68
dtrace: error on enabled probe ID 1714 (ID 961: syscall::read_nocancel:return): invalid kernel access in action #12 at DIF offset 68
dtrace: error on enabled probe ID 1714 (ID 961: syscall::read_nocancel:return): invalid kernel access in action #12 at DIF offset 68
dtrace: error on enabled probe ID 1714 (ID 961: syscall::read_nocancel:return): invalid kernel access in action #12 at DIF offset 68
dtrace: error on enabled probe ID 1714 (ID 961: syscall::read_nocancel:return): invalid kernel access in action #12 at DIF offset 68
dtrace: error on enabled probe ID 1714 (ID 961: syscall::read_nocancel:return): invalid kernel access in action #12 at DIF offset 68
close_nocancel(0x3)    = 0 0
open_nocancel("/usr/share/locale/en_US.UTF-8/LC_MONETARY\0", 0x0, 0x0)     = 3 0
fstat64(0x3, 0x7FF7BA417DD8, 0x0)    = 0 0
dtrace: error on enabled probe ID 1714 (ID 961: syscall::read_nocancel:return): invalid kernel access in action #12 at DIF offset 68
close_nocancel(0x3)    = 0 0
open_nocancel("/usr/share/locale/en_US.UTF-8/LC_NUMERIC\0", 0x0, 0x0)    = 3 0
fstat64(0x3, 0x7FF7BA417DD8, 0x0)    = 0 0
dtrace: error on enabled probe ID 1714 (ID 961: syscall::read_nocancel:return): invalid kernel access in action #12 at DIF offset 68
close_nocancel(0x3)    = 0 0
open_nocancel("/usr/share/locale/en_US.UTF-8/LC_TIME\0", 0x0, 0x0)     = 3 0
fstat64(0x3, 0x7FF7BA417DD8, 0x0)    = 0 0
dtrace: error on enabled probe ID 1714 (ID 961: syscall::read_nocancel:return): invalid kernel access in action #12 at DIF offset 68
close_nocancel(0x3)    = 0 0
open_nocancel("/usr/share/locale/en_US.UTF-8/LC_MESSAGES/LC_MESSAGES\0", 0x0, 0x0)     = 3 0
fstat64(0x3, 0x7FF7BA417DD8, 0x0)    = 0 0
dtrace: error on enabled probe ID 1714 (ID 961: syscall::read_nocancel:return): invalid kernel access in action #12 at DIF offset 68
close_nocancel(0x3)    = 0 0
ioctl(0x1, 0x4004667A, 0x7FF7BA418324)     = 0 0
ioctl(0x1, 0x40087468, 0x7FF7BA4183F0)     = 0 0
open_nocancel(".\0", 0x1100004, 0x0)     = 3 0
dtrace: error on enabled probe ID 1741 (ID 573: syscall::sysctl:return): invalid kernel access in action #10 at DIF offset 28
dtrace: error on enabled probe ID 1741 (ID 573: syscall::sysctl:return): invalid kernel access in action #10 at DIF offset 28
fstatfs64(0x3, 0x7FF7BA417AB0, 0x0)    = 0 0
getdirentries64(0x3, 0x7FAEED80FC00, 0x2000)     = 568 0
close_nocancel(0x3)    = 0 0
sigprocmask(0x1, 0x0, 0x7FF7BA418350)    = 0x0 0
sigaltstack(0x0, 0x7FF7BA418340, 0x0)    = 0 0
fstat64(0x1, 0x7FF7BA416E58, 0x0)    = 0 0
ioctl(0x1, 0x4004667A, 0x7FF7BA416EA4)     = 0 0
dtrace: error on enabled probe ID 1712 (ID 963: syscall::write_nocancel:return): invalid kernel access in action #12 at DIF offset 68
dtrace: error on enabled probe ID 1712 (ID 963: syscall::write_nocancel:return): invalid kernel access in action #12 at DIF offset 68
close_nocancel(0x1)    = 0 0
close_nocancel(0x2)    = 0 0

troubleshooting

dtrace: system integrity protection is on

[!TIP]
* iMarlso: osx/system integrity protection

# csrutil disable
# or
# csrutil enable --without dtrace
# or
# csrutil enable --without dtrace --without debug

sar

netcat

[!NOTE|label:references:]
the netcat command in linux

check particular port

$ nc -zv 127.0.0.1 22
Connection to 127.0.0.1 port 22 [tcp/ssh] succeeded!

check ports in range

$ nc -znv -w 1 127.0.0.1 20-30
nc: connectx to 127.0.0.1 port 20 (tcp) failed: Connection refused
nc: connectx to 127.0.0.1 port 21 (tcp) failed: Connection refused
Connection to 127.0.0.1 port 22 [tcp/*] succeeded!
nc: connectx to 127.0.0.1 port 23 (tcp) failed: Connection refused
nc: connectx to 127.0.0.1 port 24 (tcp) failed: Connection refused
nc: connectx to 127.0.0.1 port 25 (tcp) failed: Connection refused
nc: connectx to 127.0.0.1 port 26 (tcp) failed: Connection refused
nc: connectx to 127.0.0.1 port 27 (tcp) failed: Connection refused
nc: connectx to 127.0.0.1 port 28 (tcp) failed: Connection refused

running simple web server

$ cat > index.html <<<EOF
<!DOCTYPE html>
<html>
    <head>
        <title>Simple Netcat Server</title>
    </head>
    <body>
        <h1>Welcome to simple netcat server!<h1>
    </body>
    </body>
<html>
EOF

$ echo -e "HTTP/1.1 200 OK\n\n$(cat index.html)" | nc -l 1234

or getting more

$ while true; do echo -e "HTTP/1.1 200 OK\n\n$(cat index.html)" | nc -l -w 1 1234; done
GET / HTTP/1.1
Host: localhost:1234
Connection: keep-alive
sec-ch-ua: "Chromium";v="110", "Not A(Brand";v="24", "Google Chrome";v="110"
sec-ch-ua-mobile: ?0
sec-ch-ua-platform: "macOS"
Upgrade-Insecure-Requests: 1
User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/110.0.0.0 Safari/537.36
Accept: text/html,application/xhtml+xml,application/xml;q=0.9,image/avif,image/webp,image/apng,*/*;q=0.8,application/signed-exchange;v=b3;q=0.7
Sec-Fetch-Site: none
Sec-Fetch-Mode: navigate
Sec-Fetch-User: ?1
Sec-Fetch-Dest: document
Accept-Encoding: gzip, deflate, br
Accept-Language: en,zh-CN;q=0.9,zh;q=0.8,en-US;q=0.7

GET /favicon.ico HTTP/1.1
Host: localhost:1234
Connection: keep-alive
sec-ch-ua: "Chromium";v="110", "Not A(Brand";v="24", "Google Chrome";v="110"
sec-ch-ua-mobile: ?0
User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/110.0.0.0 Safari/537.36
sec-ch-ua-platform: "macOS"
Accept: image/avif,image/webp,image/apng,image/svg+xml,image/*,*/*;q=0.8
Sec-Fetch-Site: same-origin
Sec-Fetch-Mode: no-cors
Sec-Fetch-Dest: image
Referer: http://localhost:1234/
Accept-Encoding: gzip, deflate, br
Accept-Language: en,zh-CN;q=0.9,zh;q=0.8,en-US;q=0.7
...

reverse proxy with netcat

emulating netcat -e

$ mkfifo foo ; nc -lk 2600 0<foo | /bin/bash 1>foo

`ip`

$ ip addr show | sed -nE "s/inet\s(.*)\/[0-9]+.*\s(\w+)/\2 \1/p"
  lo0 127.0.0.1
  en0 192.168.1.71

# for linux
$ ip addr show | sed -nE "s/inet\s(.*)\/[0-9]+.*\s(\w+)/\2 \1/p" | column -to ' => '
lo0 => 127.0.0.1
en0 => 192.168.1.71

datadog

others

[!NOTE|label:references:]
完全指南：在 Linux 中如何打印和管理打印机
440+ 个免费的编程 & 计算机科学的在线课程
在 Linux 上用 DNS 实现简单的负载均衡
Python 字节码介绍

Previousdevops Nextssh

Last updated 7 days ago

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admin tools

references:
20 Command Line Tools to Monitor Linux Performance
20 Linux System Monitoring Tools Every SysAdmin Should Know
Top 25 Best Linux Performance Monitoring and Debugging Tools
http://www.thegeekstuff.com/2010/12/50-unix-linux-sysadmin-tutorials
16 commands to check hardware information on Linux
Best UNIX shell-based tools
* alebcay/awesome-shell
* zh-cn
nosarthur/awesome-shell
* rockerBOO/awesome-neovim
jlevy/the-art-of-command-line
Learn Enough Command Line to Be Dangerous
Shell Style Guide
Use Bash Strict Mode (Unless You Love Debugging)
others
bayandin/awesome-awesomeness
emijrp/awesome-awesome
kahun/awesome-sysadmin
My Minimalist Over-powered Linux Setup Guide
* devynspencer/cute_commands.sh

encryption

gpg

[!NOTE|label:references:]
* The GNU Privacy Handbook
* The GNU Privacy Guard Manual
GPG入门教程
GPG(GnuPG)入门
FlowCrypt: PGP Encryption for Gmail

basic knowledge

[!NOTE|label:references:]
to show --dump-options: gpg --dump-options

letters indicating
[!TIP|label:references:]
- 简明 GPG 概念
- GPG 密钥的能力中， [C]、[S]、[A] 均属于签名方案，只有 [E] 是加密方案
- The GNU Privacy Guard Manual : 4.2.1 How to change the configuration
- OpenPGP Message Format : 5.2.3.21. Key Flags
- How are the GPG usage flags defined in the key details listing?
- Anatomy of a GPG Key
LETTER
MEANING
flag
CONSTANT
COMMENTS
[C]
Certification
0x01
PUBKEY_USAGE_CERT
认证其他秘钥/给其他证书签名
[S]
Signing
0x02
PUBKEY_USAGE_SIG
签名,如给文件添加数字签名, 给 git commit 签名
[A]
Authenticate
0x20
PUBKEY_USAGE_AUTH
身份验证, 如 ssh 登录
[E]
Encryption
0x04 or 0x08
PUBKEY_USAGE_ENC
加密, 如给文件加密, 给邮件加密

create new key

[!NOTE|label:references:]
Generating GPG Keys
How to create GPG keypairs
Generating a new GPG key

$ gpg --full-generate-key

$ gpg --batch --gen-key <<EOF
%no-protection
Key-Type:1
Key-Length:2048
Subkey-Type:1
Subkey-Length:2048
Name-Real: <John Doe>
Name-Email: <john.doe@domain.com>
Expire-Date:0
EOF

list keys

secret keys

$ gpg --list-secret-keys --keyid-format=long
gpg: checking the trustdb
gpg: marginals needed: 3  completes needed: 1  trust model: pgp
gpg: depth: 0  valid:   1  signed:   0  trust: 0-, 0q, 0n, 0m, 0f, 1u
[keyboxd]
---------
sec   ed25519/505104FC7CD6CA33 2024-05-08 [SC]
      00D2F41050BF7D9BE6B27545505104FC7CD6CA33
uid                 [ultimate] marslo <marslo.jiao@gmail.com>
ssb   cv25519/188C36434D6B9F66 2024-05-08 [E]

public keys

$ gpg --list-public-keys --keyid-format=long
[keyboxd]
---------
pub   ed25519/5C0980808D968494 2024-05-08 [SC]
      6AADCD68E268DEF623C4DD7E5C0980808D968494
uid                 [ultimate] marslo <marslo.jiao@gmail.com>
sub   cv25519/F065036D0FF76ABA 2024-05-08 [E]

list KEYID

$ gpg --list-keys --with-colons |
      awk -F: '$1 == "pub" && ($2 == "e" || $2 == "r" || $2 == "u") { print $5 }'

with fingerprint

$ gpg --list-secret-keys --with-colons --fingerprint
sec:u:255:22:5C0980808D968494:1715138996:::u:::scESC:::+::ed25519:::0:
fpr:::::::::6AADCD68E268DEF623C4DD7E5C0980808D968494:
grp:::::::::DA2F273B9FCDBCE44E8F5B1590CC29F774C557A5:
uid:u::::1715138996::689D1C164C7C46F315D0FF60C5CDE6E509C6D853::marslo <marslo.jiao@gmail.com>::::::::::0:
ssb:u:255:18:F065036D0FF76ABA:1715138996::::::e:::+::cv25519::
fpr:::::::::B6550514914F4E14976755BBF065036D0FF76ABA:
grp:::::::::C55CD6EE8B06EC939090352069AB9D37CFA0C7FA:

# list fingerprint only
$ gpg --list-keys --with-colons | awk -F: '$1 == "fpr" { print $10 }'
6AADCD68E268DEF623C4DD7E5C0980808D968494
B6550514914F4E14976755BBF065036D0FF76ABA

# or
$ gpg --list-secret-keys --with-colons --fingerprint | sed -n 's/^fpr:::::::::\([[:alnum:]]\+\):/\1/p'
6AADCD68E268DEF623C4DD7E5C0980808D968494
B6550514914F4E14976755BBF065036D0FF76ABA

remove keys

remove all keys

$ gpg --yes --delete-secret-and-public-key "marslo"
gpg (GnuPG) 2.4.5; Copyright (C) 2024 g10 Code GmbH
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.

sec  ed25519/133597088DEF3074 2024-05-08 marslo (marslo) <marslo.jiao@gmail.com>

Delete this key from the keyring? (y/N) y
This is a secret key! - really delete? (y/N) y

pub  ed25519/133597088DEF3074 2024-05-08 marslo (marslo) <marslo.jiao@gmail.com>
Delete this key from the keyring? (y/N) y

or via --batch

$ gpg --list-keys --with-colons \
    | awk -F: '$1 == "pub" && ($2 == "e" || $2 == "r" || $2 == "u") { print $5 }' \
    | xargs gpg --batch --yes --delete-secret-and-public-key

or via fingerprint

$ gpg --fingerprint --with-colons ${GPG_KEY} |\
      grep "^fpr" |\
      sed -n 's/^fpr:::::::::\([[:alnum:]]\+\):/\1/p' |\
      xargs gpg --batch --delete-secret-keys

export/import keys

[!NOTE|label:references:]
How to export a GPG private key and public key to a file
Moving GPG Keys Privately

export

export public key

$ gpg --output public.pgp --armor --export <KEYID>

check content

$ gpg --armor --export <KEYID>

# i.e.:
$ gpg --armor --export marslo
-----BEGIN PGP PUBLIC KEY BLOCK-----
...
-----END PGP PUBLIC KEY BLOCK-----

export secret key

$ gpg --output private.pgp --armor --export-secret-key <KEYID>
# or
$ gpg -o ~/private.asc --export-secret-key <KEYID>

export and ssh

$ gpg --export-secret-key SOMEKEYID | ssh othermachine gpg --import

$ gpg --output public.gpg --export SOMEKEYID && \
$ gpg --output - --export-secret-key SOMEKEYID |\
      cat public.gpg - |\
      gpg --armor --output keys.asc --symmetric --cipher-algo AES256

check content

$ gpg --armor --export-secret-keys <KEYID>

# i.e.:
$ gpg --armor --export-secret-keys marslo
-----BEGIN PGP PRIVATE KEY BLOCK-----
...
-----END PGP PRIVATE KEY BLOCK-----

backup keys

$ gpg --output backupkeys.pgp --armor --export-secret-keys --export-options export-backup <KEYID>
# or
$ gpg --output backupkeys.pgp --armor --export --export-options export-backup <KEYID>

import

[!NOTE|label:references:]
How to import secret keys into GPG keychain
pass and gpg: No public key
How to import secret gpg key (copied from one machine to another)?

# import private key
$ gpg --import private.pgp
gpg: /home/marslo/.gnupg/trustdb.gpg: trustdb created
gpg: key 5C0980808D968494: public key "marslo <marslo.jiao@gmail.com>" imported
gpg: key 5C0980808D968494: secret key imported
gpg: Total number processed: 1
gpg:               imported: 1
gpg:       secret keys read: 1
gpg:   secret keys imported: 1

# list keys
$ gpg --list-keys
/home/marslo/.gnupg/pubring.kbx
-------------------------------
pub   ed25519 2024-05-08 [SC]
      6AADCD68E268DEF623C4DD7E5C0980808D968494
uid           [ unknown] marslo <marslo.jiao@gmail.com>
sub   cv25519 2024-05-08 [E]

# trust
$ gpg --edit-key 6AADCD68E268DEF623C4DD7E5C0980808D968494 trust quit
  1 = I don't know or won't say
  2 = I do NOT trust
  3 = I trust marginally
  4 = I trust fully
  5 = I trust ultimately
  m = back to the main menu

gpg> Your decision? 5
gpg> Do you really want to set this key to ultimate trust? (y/N) y

# check key again
$ gpg --list-keys
gpg: checking the trustdb
gpg: marginals needed: 3  completes needed: 1  trust model: pgp
gpg: depth: 0  valid:   1  signed:   0  trust: 0-, 0q, 0n, 0m, 0f, 1u
/home/marslo/.gnupg/pubring.kbx
-------------------------------
pub   ed25519 2024-05-08 [SC]
      6AADCD68E268DEF623C4DD7E5C0980808D968494
uid           [ultimate] marslo <marslo.jiao@gmail.com>
sub   cv25519 2024-05-08 [E]

import publid key

# import public key
$ gpg --import public.pgp
gpg: key 5C0980808D968494: "marslo <marslo.jiao@gmail.com>" not changed
gpg: Total number processed: 1
gpg:              unchanged: 1

trust key

# verify available
$ gpg --edit-key <KEYID>

# trust
$ gpg --edit-key <KEYID>
gpg> trust
gpg> save
gpg> quit

recover from backup keys

$ gpg --import-options restore --import backupkeys.pgp

usage

[!NOTE|label:references:]
GPG使用方法总结（密钥管理，加解密文件）

pass

[!NOTE]
pass: the standard unix password manager
git repo: password-store
video: How to Use Pass Which Is a Command Line Password Manager
How to Use Pass Which Is a Command Line Password Manager
archlinux: pass
compatible clients
Clever uses of pass, the Unix password manager
Configuring Pass, the Standard Unix Password Manager

env

[!NOTE|label:references:]
completion
environment variable
PASSWORD_STORE_DIR
PASSWORD_STORE_KEY
PASSWORD_STORE_GENERATED_LENGTH
PASSWORD_STORE_CHARACTER_SET
PASSWORD_STORE_CHARACTER_SET_NO_SYMBOLS
PASSWORD_STORE_CLIP_TIME
PASSWORD_STORE_EXTENSIONS_DIR
PASSWORD_STORE_ENABLE_EXTENSIONS
PASSWORD_STORE_SIGNING_KEY

$ export PASSWORD_STORE_DIR=~/.password-store

install

# osx
$ brew install pass

# ubuntu/debian
$ sudo apt-get install pass

# fedora/rhel
$ sudo yum install pass

init
[!TIP|label:references:]
- How to manage Linux passwords with the pass command
- I try to add passwords to the "pass" password manager. But my attempts fail with "no public key" GPG errors. Why?
- to avoid the issue like:
  $ pass generate test 30 gpg: marslo: skipped: No public key gpg: [stdin]: encryption failed: No public key Password encryption aborted.
```
$ gpg --full-generate-key
```

insert

$ pass insert <NAME>

# i.e.:
$ pass insert test
Enter password for test: abc
Retype password for test: abc
$ pass test
abc

# copy
$ pass -c test
Copied test to clipboard. Will clear in 45 seconds.

generate

[!NOTE|label:references:]
PASSWORD_STORE_CHARACTER_SET_NO_SYMBOLS isn't respected
[pass] Provide symbol set as command line argument
How to generate secure passwords using terminal (Mac/Linux) ?
default and envs
PASSWORD_STORE_DIR=$HOME/.password-store
PASSWORD_STORE_EXTENSIONS_DIR=${PASSWORD_STORE_DIR}/.extensions
PASSWORD_STORE_CLIP_TIME=45
PASSWORD_STORE_GENERATED_LENGTH=25
others:
PASSWORD_STORE_CHARACTER_SET='[:alnum:].,!?&*%_~$#^@{}[]()<>|=/\+-'
Vim: word vs WORD

customize charset

$ export PASSWORD_STORE_CHARACTER_SET='a-zA-Z0-9'
$ yes | pass generate test 30
The generated password for test is:
HnD7XyeFDtOrw5oDhn22U8AjHVV9cf
$ yes | pass generate test 30
The generated password for test is:
t57PYCw4r0tHSXCa4zW2DVGNuizQ1k

$ export PASSWORD_STORE_CHARACTER_SET='a-zA-Z0-9()'
$ yes | pass generate test 50
The generated password for test is:
wof1Hw92QXe(G3)MkMRp5Wx3UCMgHIpt)7ENNn(f8r(ZRcztQ1
$ yes | pass generate test 30
The generated password for test is:
60m2XHtqfTsvfJT(YYV1wKlBBoOJYb

generate qrcode
```
$ pass generate <name> --qrcode
```

generate via /dev/urandom

$ head /dev/urandom | tr -dc 'A-Za-z0-9!@#$%^&*()' | head -c 32 && echo
xGPqC%MeE2HU3NkH#JeA##RB^YbX49cd

$ head /dev/urandom | tr -dc 'A-Za-z0-9!@#$%^&*()?:_-~+<=>' | head -c 32 && echo
e?XEGaD68^FNYI5#E^aFVgv:(6_pL>!I

$ head /dev/urandom | tr -dc 'A-Za-z0-9!"#$%&'\''()*+,-./:;<=>?@[\]^_`{|}~' | head -c 32 && echo
+&7<o(zfE[WC30v'D[&RH~;qM-8J>oQC

generate via openssl

$ openssl rand -base64 32
DfXwoBz8UAel09qN1rR97luKy+aFuC8N0Fua+YaSW8A=

# or: https://www.commandlinefu.com/commands/view/24565/generate-a-random-password-30-characters-long
$ openssl rand -rand /dev/urandom -base64 32

remove

$ pass rm test -f
removed '/Users/marslo/.marslo/.password-store/test.gpg'

advanced usage

[!NOTE|label:references:]
extensions
roddhjav/pass-tomb
tadfisher/pass-otp) | pass-otp.bash.completion
roddhjav/pass-import
roddhjav/pass-update
roddhjav/pass-audit
ayushnix/pass-coffin
ayushnix/pass-tessen
additional tools
Pass for Alfred

alfred workflow

$ brew isntall --HEAD pinentry-mac

# using pinentry-mac instead of pinentry for alfred workflow
$ [[ -d "$HOME/.gnupg" ]] || mkdir "$HOME/.gnupg"
$ echo "pinentry-program $(brew --prefix)/bin/pinentry-mac" > $HOME/.gnupg/gpg-agent.conf
$ gpgconf --kill gpg-agent                           # restart the agent

pw() {
  export PASSWORD_STORE_CLIP_TIME=8
  export PASSWORD_STORE_X_SELECTION=primary
  pass -c2 $1; sleep 5; pass -c $1; sleep 5; pass otp -c $1; exit
}

extend

# ~/.bashrc
$ alias passred="PASSWORD_STORE_DIR=~/.pass/red pass"
$ alias passblue="PASSWORD_STORE_DIR=~/.pass/blue pass"

$ cat /usr/share/bash-completion/completions/pass
_passred(){
    PASSWORD_STORE_DIR=~/.pass/red/ _pass
}
complete -o filenames -o nospace -F _passred passred
_passblue(){
    PASSWORD_STORE_DIR=~/.pass/blue/ _pass
}
complete -o filenames -o nospace -F _passblue passblue
$ source /usr/share/bash-completion/completions/pass

git

$ git config --global credential.helper /usr/bin/pass-git-helper

$ cat ~/.gitconfig
[github.com]
target=dev/github

[*.fooo-bar.*]
target=dev/fooo-bar

client

# create local password store
$ pass init <gpg key id>
# enable management of local changes through git
$ pass git init
# add the the remote git repository as 'origin'
$ pass git remote add origin user@server:~/.password-store
# push your local pass history
$ pass git push -u --all

plugins

pass-otp

[!NOTE|label:references:]
#137 Bash completion

# --- install ---
# osx
$ brew install pass-otp
$ brew uses --recursive --installed oath-toolkit
pass-otp

# --- usage ---
## init
$ pass otp insert -e sandbox/otp
Enter otpauth:// URI for sandbox/otp: otpauth://totp/totp-secret?secret=sandbox
## show otp code
$ pass otp sandbox/otp
148395

OTP

[!NOTE|label:references:]
OATH-Toolkit
Use oathtool Linux command line for 2 step verification (2FA)
One-Time-Passwords using oathtool on Ubuntu 14.04(+)

pass-otp

[!NOTE|label:references:]

tips:

$ brew which-formula oathtool
oath-toolkit

$ brew uses --recursive --installed oath-toolkit
pass-otp

$ oathtool $(openssl rand -hex 16)
848050

PGP

[!NOTE|label:references:]
Protecting Code Integrity with PGP
Protecting Code Integrity with PGP — Part 1: Basic Concepts and Tools | 用 PGP 保护代码完整性（一）：基本概念和工具
Protecting Code Integrity with PGP — Part 2: Generating Your Master Key | 用 PGP 保护代码完整性（二）：生成你的主密钥
Protecting Code Integrity with PGP — Part 3: Generating PGP Subkeys | 用 PGP 保护代码完整性（三）：生成 PGP 子密钥
Protecting Code Integrity with PGP — Part 4: Moving Your Master Key to Offline Storage | 用 PGP 保护代码完整性（四）：将主密钥移到离线存储中
Protecting Code Integrity with PGP — Part 5: Moving Subkeys to a Hardware Device | 用 PGP 保护代码完整性（五）：将子密钥移到一个硬件设备中
Protecting Code Integrity with PGP — Part 6: Using PGP with Git | 用 PGP 保护代码完整性（六）：在 Git 上使用 PGP
Protecting Code Integrity with PGP — Part 7: Protecting Online Accounts | 用 PGP 保护代码完整性（七）：保护在线帐户

passwd

[!NOTE|label:references:]
Managing Linux users with the passwd command

network tools

[!NOTE|label:see also:]
iMarslo : linux/network

`vnstat`

$ vnstat -l 1 -i en7
Monitoring en7...    (press CTRL-C to stop)

   rx:     4.10 kbit/s   21.00 KiB          tx:         0 bit/s   6.00 KiB^C

 en7  /  traffic statistics
                           rx         |       tx
--------------------------------------+------------------
  bytes                    21.00 KiB  |        6.00 KiB
--------------------------------------+------------------
          max           53.25 kbit/s  |    12.29 kbit/s
      average           17.20 kbit/s  |     4.92 kbit/s
          min                0 bit/s  |         0 bit/s
--------------------------------------+------------------
  packets                         60  |              52
--------------------------------------+------------------
          max                 15 p/s  |          16 p/s
      average                  6 p/s  |           5 p/s
          min                  2 p/s  |           0 p/s
--------------------------------------+------------------
  time                    10 seconds

`ipcalc`

$ ipcalc 10.25.130.2/23
Address:   10.25.130.2          00001010.00011001.1000001 0.00000010
Netmask:   255.255.254.0 = 23   11111111.11111111.1111111 0.00000000
Wildcard:  0.0.1.255            00000000.00000000.0000000 1.11111111
=>
Network:   10.25.130.0/23       00001010.00011001.1000001 0.00000000
HostMin:   10.25.130.1          00001010.00011001.1000001 0.00000001
HostMax:   10.25.131.254        00001010.00011001.1000001 1.11111110
Broadcast: 10.25.131.255        00001010.00011001.1000001 1.11111111
Hosts/Net: 510                   Class A, Private Internet

$ ipcalc 10.25.131.1/23
Address:   10.25.131.1          00001010.00011001.1000001 1.00000001
Netmask:   255.255.254.0 = 23   11111111.11111111.1111111 0.00000000
Wildcard:  0.0.1.255            00000000.00000000.0000000 1.11111111
=>
Network:   10.25.130.0/23       00001010.00011001.1000001 0.00000000
HostMin:   10.25.130.1          00001010.00011001.1000001 0.00000001
HostMax:   10.25.131.254        00001010.00011001.1000001 1.11111110
Broadcast: 10.25.131.255        00001010.00011001.1000001 1.11111111
Hosts/Net: 510                   Class A, Private Internet

`iostat`

$ iostat
              disk0       cpu    load average
    KB/t  tps  MB/s  us sy id   1m   5m   15m
   19.85   37  0.72   3  1 96  1.78 1.90 1.69

`tcpdump`

[!NOTE|label:references:]
* Tcpdump

$ sudo tcpdump -A -i en7
tcpdump: verbose output suppressed, use -v or -vv for full protocol decode
listening on en7, link-type EN10MB (Ethernet), capture size 262144 bytes
00:33:02.787671 IP 10.25.130.117.53629 > a23-43-240-92.deploy.static.akamaitechnologies.com.https: Flags [.], ack 697481089, win 2048, length 0
E..(....@...
..u.+.\.}..r...)...P...:...
00:33:02.790119 IP 10.25.130.117.51541 > sh-vdc01.mycompany.com.domain: 53089+ PTR? 92.240.43.23.in-addr.arpa. (43)
E..GP....._.
..u
&t..U.5.3...a...........92.240.43.23.in-addr.arpa.....
00:33:02.812866 ARP, Request who-has gw-voice-idf.cdu-cn.mycompany.com tell gw-vg224-idf.cdu-cn.mycompany.com, length 46
....
....
13 packets captured
25 packets received by filter
0 packets dropped by kernel

$ sudo tcpdump -n -i any src or dst target.ip.address [ -v ]

# i.e.
$ sudo tcpdump -n -i any src or dst git.domain.com -v
tcpdump: data link type PKTAP
tcpdump: listening on any, link-type PKTAP (Apple DLT_PKTAP), snapshot length 524288 bytes
00:02:55.698822 IP (tos 0x0, ttl 64, id 0, offset 0, flags [DF], proto TCP (6), length 52)
    10.25.130.104.63447 > 10.69.78.140.29418: Flags [F.], cksum 0x8fe0 (correct), seq 2566890566, ack 4019765769, win 2058, options [nop,nop,TS val 1955309758 ecr 154499413], length 0

`dstat`

strace

[!NOTE|label:references:]
I have a tab completion that hangs, is it possible to use strace to find out what is going on?
Resolve nested aliases to their source commands

$ ... run cmd ...

# or
$ pid=$(echo ??)
$ sudo strace -fp ${pid} -o log

# or
$ sudo -v
$ sudo strace -fp $$ -o log &

# -- more --
$ set -o functrace xtrace
$ PS4=' ${BASH_SOURCE}:$FUNCNAME:$LINENO: '

intercept stdout/stderr of another process

$ strace -ff -e trace=write -e write=1,2 -p SOME_PID

# https://www.commandlinefu.com/commands/view/5450/intercept-stdoutstderr-of-another-process
$ strace -ff -e write=1,2 -s 1024 -p PID 2>&1 | grep "^ |" | cut -c11-60 | sed -e 's/ //g' | xxd -r -p

# https://www.commandlinefu.com/commands/view/6743/intercept-stdoutstderr-of-another-process-or-disowned-process
$ strace -e write=1,2 -p $PID 2>&1 | sed -un "/^ |/p" | sed -ue "s/^.\{9\}\(.\{50\}\).\+/\1/g" -e 's/ //g' | xxd -r -p

debug script

$ strace -e clone,execve,pipe,dup2 \
         -f bash -c 'cat <(/bin/true) <(/bin/false) <(/bin/echo)'
execve("/usr/bin/bash", ["bash", "-c", "cat <(/bin/true) <(/bin/false) <"...], 0x7fff9b9c6f98 /* 75 vars */) = 0
pipe([3, 4])                            = 0
dup2(3, 63)                             = 63
clone(child_stack=NULL, flags=CLONE_CHILD_CLEARTID|CLONE_CHILD_SETTID|SIGCHLD, child_tidptr=0x7f7cf6a8ca10) = 289963
strace: Process 289963 attached
[pid 289962] pipe([3, 4])               = 0
[pid 289962] dup2(3, 62)                = 62
[pid 289962] clone(child_stack=NULL, flags=CLONE_CHILD_CLEARTID|CLONE_CHILD_SETTID|SIGCHLD <unfinished ...>
[pid 289963] dup2(4, 1)                 = 1
[pid 289962] <... clone resumed>, child_tidptr=0x7f7cf6a8ca10) = 289964
strace: Process 289964 attached
[pid 289963] clone(child_stack=NULL, flags=CLONE_CHILD_CLEARTID|CLONE_CHILD_SETTID|SIGCHLD <unfinished ...>
[pid 289962] pipe([3, 4])               = 0
strace: Process 289965 attached
[pid 289963] <... clone resumed>, child_tidptr=0x7f7cf6a8ca10) = 289965
[pid 289962] dup2(3, 61)                = 61
[pid 289962] clone(child_stack=NULL, flags=CLONE_CHILD_CLEARTID|CLONE_CHILD_SETTID|SIGCHLD <unfinished ...>
[pid 289964] dup2(4, 1)                 = 1
[pid 289965] execve("/bin/true", ["/bin/true"], 0x55ec7c007680 /* 73 vars */strace: Process 289966 attached
 <unfinished ...>
[pid 289962] <... clone resumed>, child_tidptr=0x7f7cf6a8ca10) = 289966
[pid 289964] clone(child_stack=NULL, flags=CLONE_CHILD_CLEARTID|CLONE_CHILD_SETTID|SIGCHLD <unfinished ...>
[pid 289965] <... execve resumed>)      = 0
strace: Process 289967 attached
[pid 289964] <... clone resumed>, child_tidptr=0x7f7cf6a8ca10) = 289967
[pid 289966] dup2(4, 1)                 = 1
[pid 289967] execve("/bin/false", ["/bin/false"], 0x55ec7c007af0 /* 73 vars */ <unfinished ...>
[pid 289966] clone(child_stack=NULL, flags=CLONE_CHILD_CLEARTID|CLONE_CHILD_SETTID|SIGCHLD, child_tidptr=0x7f7cf6a8ca10) = 289968
[pid 289967] <... execve resumed>)      = 0
strace: Process 289968 attached
[pid 289962] execve("/usr/bin/cat", ["cat", "/dev/fd/63", "/dev/fd/62", "/dev/fd/61"], 0x55ec7c007bc0 /* 73 vars */ <unfinished ...>
[pid 289968] execve("/bin/echo", ["/bin/echo"], 0x55ec7c007e20 /* 73 vars */ <unfinished ...>
[pid 289962] <... execve resumed>)      = 0
[pid 289968] <... execve resumed>)      = 0
[pid 289965] +++ exited with 0 +++
[pid 289963] --- SIGCHLD {si_signo=SIGCHLD, si_code=CLD_EXITED, si_pid=289965, si_uid=10564, si_status=0, si_utime=0, si_stime=0} ---
[pid 289963] +++ exited with 0 +++
[pid 289962] --- SIGCHLD {si_signo=SIGCHLD, si_code=CLD_EXITED, si_pid=289963, si_uid=10564, si_status=0, si_utime=0, si_stime=0} ---
[pid 289967] +++ exited with 1 +++
[pid 289964] --- SIGCHLD {si_signo=SIGCHLD, si_code=CLD_EXITED, si_pid=289967, si_uid=10564, si_status=1, si_utime=0, si_stime=0} ---
[pid 289964] +++ exited with 1 +++
[pid 289962] --- SIGCHLD {si_signo=SIGCHLD, si_code=CLD_EXITED, si_pid=289964, si_uid=10564, si_status=1, si_utime=0, si_stime=0} ---

[pid 289968] +++ exited with 0 +++
[pid 289966] --- SIGCHLD {si_signo=SIGCHLD, si_code=CLD_EXITED, si_pid=289968, si_uid=10564, si_status=0, si_utime=0, si_stime=0} ---
[pid 289966] +++ exited with 0 +++
--- SIGCHLD {si_signo=SIGCHLD, si_code=CLD_EXITED, si_pid=289966, si_uid=10564, si_status=0, si_utime=0, si_stime=0} ---
+++ exited with 0 +++

xtrace

xtrace() {
  local eval_cmd
  printf -v eval_cmd '%q' "${@}"
  { set -x
    eval "${eval_cmd}"
  } 2>&1 | grep '^++'
  return "${PIPESTATUS[0]}"
}

`dtruss`

[!TIP|label:references:]
the MacOS alternatives strace
Using modified dtruss.sh

$ sudo dtruss <cmd>

$ sudo dtruss ls
dtrace: system integrity protection is on, some features will not be available

SYSCALL(args)      = return
README.md   artifactory  devops   jenkins  osx    screenshot  vim
SUMMARY.md  cheatsheet   english  linux    programming  tools     virtualization
munmap(0x1155AB000, 0xA0000)     = 0 0
munmap(0x11564B000, 0x8000)    = 0 0
munmap(0x115653000, 0x4000)    = 0 0
munmap(0x115657000, 0x4000)    = 0 0
munmap(0x11565B000, 0x58000)     = 0 0
fsgetpath(0x7FF7BA418580, 0x400, 0x7FF7BA418568)     = 40 0
fsgetpath(0x7FF7BA418580, 0x400, 0x7FF7BA418568)     = 14 0
csrctl(0x0, 0x7FF7BA41898C, 0x4)     = -1 1
__mac_syscall(0x7FF819AD4E1B, 0x2, 0x7FF7BA4187F0)     = 0 0
csrctl(0x0, 0x7FF7BA41899C, 0x4)     = -1 1
__mac_syscall(0x7FF819AD1DA4, 0x5A, 0x7FF7BA418930)    = 0 0
dtrace: error on enabled probe ID 1741 (ID 573: syscall::sysctl:return): invalid kernel access in action #10 at DIF offset 28
dtrace: error on enabled probe ID 1741 (ID 573: syscall::sysctl:return): invalid kernel access in action #10 at DIF offset 28
dtrace: error on enabled probe ID 1741 (ID 573: syscall::sysctl:return): invalid kernel access in action #10 at DIF offset 28
dtrace: error on enabled probe ID 1741 (ID 573: syscall::sysctl:return): invalid kernel access in action #10 at DIF offset 28
open("/\0", 0x20100000, 0x0)     = 3 0
openat(0x3, "System/Cryptexes/OS\0", 0x100000, 0x0)    = 4 0
dup(0x4, 0x0, 0x0)     = 5 0
fstatat64(0x4, 0x7FF7BA4176D1, 0x7FF7BA417AD0)     = 0 0
openat(0x4, "System/Library/dyld/\0", 0x100000, 0x0)     = 6 0
fcntl(0x6, 0x32, 0x7FF7BA417760)     = 0 0
dup(0x6, 0x0, 0x0)     = 7 0
dup(0x5, 0x0, 0x0)     = 8 0
close(0x3)     = 0 0
close(0x5)     = 0 0
close(0x4)     = 0 0
close(0x6)     = 0 0
shared_region_check_np(0x7FF7BA418048, 0x0, 0x0)     = 0 0
fsgetpath(0x7FF7BA4185B0, 0x400, 0x7FF7BA4184E8)     = 83 0
fcntl(0x8, 0x32, 0x7FF7BA4185B0)     = 0 0
close(0x8)     = 0 0
close(0x7)     = 0 0
getfsstat64(0x0, 0x0, 0x2)     = 9 0
getfsstat64(0x106102040, 0x4C38, 0x2)    = 9 0
getattrlist("/\0", 0x7FF7BA4184F0, 0x7FF7BA418460)     = 0 0
stat64("/System/Volumes/Preboot/Cryptexes/OS/System/Library/dyld/dyld_shared_cache_x86_64h\0", 0x7FF7BA418828, 0x0)    = 0 0
dtrace: error on enabled probe ID 1690 (ID 845: syscall::stat64:return): invalid address (0x0) in action #11 at DIF offset 12
stat64("/usr/local/Cellar/coreutils/9.4/bin/gls\0", 0x7FF7BA417CC0, 0x0)     = 0 0
open("/usr/local/Cellar/coreutils/9.4/bin/gls\0", 0x0, 0x0)    = 3 0
mmap(0x0, 0x33358, 0x1, 0x40002, 0x3, 0x0)     = 0x105B18000 0
fcntl(0x3, 0x32, 0x7FF7BA417DD0)     = 0 0
close(0x3)     = 0 0
munmap(0x105B18000, 0x33358)     = 0 0
stat64("/usr/local/Cellar/coreutils/9.4/bin/gls\0", 0x7FF7BA418220, 0x0)     = 0 0
stat64("/usr/lib/libSystem.B.dylib\0", 0x7FF7BA417230, 0x0)    = -1 2
stat64("/System/Volumes/Preboot/Cryptexes/OS/usr/lib/libSystem.B.dylib\0", 0x7FF7BA4171E0, 0x0)    = -1 2
stat64("/usr/lib/libSystem.B.dylib\0", 0x7FF7BA417230, 0x0)    = -1 2
stat64("/usr/lib/libobjc.A.dylib\0", 0x7FF7BA414E80, 0x0)    = -1 2
stat64("/System/Volumes/Preboot/Cryptexes/OS/usr/lib/libobjc.A.dylib\0", 0x7FF7BA414E30, 0x0)    = -1 2
stat64("/usr/lib/libobjc.A.dylib\0", 0x7FF7BA414E80, 0x0)    = -1 2
stat64("/usr/lib/system/libsystem_blocks.dylib\0", 0x7FF7BA414E80, 0x0)    = -1 2
stat64("/System/Volumes/Preboot/Cryptexes/OS/usr/lib/system/libsystem_blocks.dylib\0", 0x7FF7BA414E20, 0x0)    = -1 2
stat64("/usr/lib/system/libsystem_blocks.dylib\0", 0x7FF7BA414E80, 0x0)    = -1 2
stat64("/usr/lib/system/libxpc.dylib\0", 0x7FF7BA414E80, 0x0)    = -1 2
stat64("/System/Volumes/Preboot/Cryptexes/OS/usr/lib/system/libxpc.dylib\0", 0x7FF7BA414E30, 0x0)  = -1 2
stat64("/usr/lib/system/libxpc.dylib\0", 0x7FF7BA414E80, 0x0)    = -1 2
stat64("/usr/lib/system/libsystem_trace.dylib\0", 0x7FF7BA414E80, 0x0)     = -1 2
stat64("/System/Volumes/Preboot/Cryptexes/OS/usr/lib/system/libsystem_trace.dylib\0", 0x7FF7BA414E20, 0x0)     = -1 2
stat64("/usr/lib/system/libsystem_trace.dylib\0", 0x7FF7BA414E80, 0x0)     = -1 2
stat64("/usr/lib/system/libcorecrypto.dylib\0", 0x7FF7BA414E80, 0x0)     = -1 2
stat64("/System/Volumes/Preboot/Cryptexes/OS/usr/lib/system/libcorecrypto.dylib\0", 0x7FF7BA414E30, 0x0) = -1 2
stat64("/usr/lib/system/libcorecrypto.dylib\0", 0x7FF7BA414E80, 0x0)     = -1 2
stat64("/usr/lib/system/libsystem_malloc.dylib\0", 0x7FF7BA414E80, 0x0)    = -1 2
stat64("/System/Volumes/Preboot/Cryptexes/OS/usr/lib/system/libsystem_malloc.dylib\0", 0x7FF7BA414E20, 0x0)    = -1 2
stat64("/usr/lib/system/libsystem_malloc.dylib\0", 0x7FF7BA414E80, 0x0)    = -1 2
stat64("/usr/lib/system/libdispatch.dylib\0", 0x7FF7BA414E80, 0x0)     = -1 2
stat64("/System/Volumes/Preboot/Cryptexes/OS/usr/lib/system/libdispatch.dylib\0", 0x7FF7BA414E30, 0x0)   = -1 2
stat64("/usr/lib/system/libdispatch.dylib\0", 0x7FF7BA414E80, 0x0)     = -1 2
stat64("/usr/lib/system/libsystem_featureflags.dylib\0", 0x7FF7BA414E80, 0x0)    = -1 2
stat64("/System/Volumes/Preboot/Cryptexes/OS/usr/lib/system/libsystem_featureflags.dylib\0", 0x7FF7BA414E20, 0x0)    = -1 2
stat64("/usr/lib/system/libsystem_featureflags.dylib\0", 0x7FF7BA414E80, 0x0)    = -1 2
stat64("/usr/lib/system/libsystem_c.dylib\0", 0x7FF7BA414E80, 0x0)     = -1 2
stat64("/System/Volumes/Preboot/Cryptexes/OS/usr/lib/system/libsystem_c.dylib\0", 0x7FF7BA414E30, 0x0)   = -1 2
stat64("/usr/lib/system/libsystem_c.dylib\0", 0x7FF7BA414E80, 0x0)     = -1 2
stat64("/usr/lib/libc++.1.dylib\0", 0x7FF7BA414E80, 0x0)     = -1 2
stat64("/System/Volumes/Preboot/Cryptexes/OS/usr/lib/libc++.1.dylib\0", 0x7FF7BA414E30, 0x0)     = -1 2
stat64("/usr/lib/libc++.1.dylib\0", 0x7FF7BA414E80, 0x0)     = -1 2
stat64("/usr/lib/libc++abi.dylib\0", 0x7FF7BA414E80, 0x0)    = -1 2
stat64("/System/Volumes/Preboot/Cryptexes/OS/usr/lib/libc++abi.dylib\0", 0x7FF7BA414E30, 0x0)    = -1 2
stat64("/usr/lib/libc++abi.dylib\0", 0x7FF7BA414E80, 0x0)    = -1 2
stat64("/usr/lib/system/libdyld.dylib\0", 0x7FF7BA414E80, 0x0)     = -1 2
stat64("/System/Volumes/Preboot/Cryptexes/OS/usr/lib/system/libdyld.dylib\0", 0x7FF7BA414E30, 0x0)   = -1 2
stat64("/usr/lib/system/libdyld.dylib\0", 0x7FF7BA414E80, 0x0)     = -1 2
stat64("/usr/lib/system/libsystem_info.dylib\0", 0x7FF7BA414E80, 0x0)    = -1 2
stat64("/System/Volumes/Preboot/Cryptexes/OS/usr/lib/system/libsystem_info.dylib\0", 0x7FF7BA414E30, 0x0)    = -1 2
stat64("/usr/lib/system/libsystem_info.dylib\0", 0x7FF7BA414E80, 0x0)    = -1 2
stat64("/usr/lib/system/libsystem_darwin.dylib\0", 0x7FF7BA414E80, 0x0)    = -1 2
stat64("/System/Volumes/Preboot/Cryptexes/OS/usr/lib/system/libsystem_darwin.dylib\0", 0x7FF7BA414E20, 0x0)    = -1 2
stat64("/usr/lib/system/libsystem_darwin.dylib\0", 0x7FF7BA414E80, 0x0)    = -1 2
stat64("/usr/lib/system/libsystem_notify.dylib\0", 0x7FF7BA414E80, 0x0)    = -1 2
stat64("/System/Volumes/Preboot/Cryptexes/OS/usr/lib/system/libsystem_notify.dylib\0", 0x7FF7BA414E20, 0x0)    = -1 2
stat64("/usr/lib/system/libsystem_notify.dylib\0", 0x7FF7BA414E80, 0x0)    = -1 2
stat64("/usr/lib/system/libsystem_networkextension.dylib\0", 0x7FF7BA414E80, 0x0)    = -1 2
stat64("/System/Volumes/Preboot/Cryptexes/OS/usr/lib/system/libsystem_networkextension.dylib\0", 0x7FF7BA414E20, 0x0)    = -1 2
stat64("/usr/lib/system/libsystem_networkextension.dylib\0", 0x7FF7BA414E80, 0x0)    = -1 2
stat64("/usr/lib/system/libsystem_asl.dylib\0", 0x7FF7BA414E80, 0x0)     = -1 2
stat64("/System/Volumes/Preboot/Cryptexes/OS/usr/lib/system/libsystem_asl.dylib\0", 0x7FF7BA414E30, 0x0) = -1 2
stat64("/usr/lib/system/libsystem_asl.dylib\0", 0x7FF7BA414E80, 0x0)     = -1 2
stat64("/usr/lib/system/libsystem_symptoms.dylib\0", 0x7FF7BA414E80, 0x0)    = -1 2
stat64("/System/Volumes/Preboot/Cryptexes/OS/usr/lib/system/libsystem_symptoms.dylib\0", 0x7FF7BA414E20, 0x0)    = -1 2
stat64("/usr/lib/system/libsystem_symptoms.dylib\0", 0x7FF7BA414E80, 0x0)    = -1 2
stat64("/usr/lib/system/libsystem_containermanager.dylib\0", 0x7FF7BA414E80, 0x0)    = -1 2
stat64("/System/Volumes/Preboot/Cryptexes/OS/usr/lib/system/libsystem_containermanager.dylib\0", 0x7FF7BA414E20, 0x0)    = -1 2
stat64("/usr/lib/system/libsystem_containermanager.dylib\0", 0x7FF7BA414E80, 0x0)    = -1 2
stat64("/usr/lib/system/libsystem_configuration.dylib\0", 0x7FF7BA414E80, 0x0)     = -1 2
stat64("/System/Volumes/Preboot/Cryptexes/OS/usr/lib/system/libsystem_configuration.dylib\0", 0x7FF7BA414E20, 0x0)     = -1 2
stat64("/usr/lib/system/libsystem_configuration.dylib\0", 0x7FF7BA414E80, 0x0)     = -1 2
stat64("/usr/lib/system/libsystem_sandbox.dylib\0", 0x7FF7BA414E80, 0x0)     = -1 2
stat64("/System/Volumes/Preboot/Cryptexes/OS/usr/lib/system/libsystem_sandbox.dylib\0", 0x7FF7BA414E20, 0x0)     = -1 2
stat64("/usr/lib/system/libsystem_sandbox.dylib\0", 0x7FF7BA414E80, 0x0)     = -1 2
stat64("/usr/lib/system/libquarantine.dylib\0", 0x7FF7BA414E80, 0x0)     = -1 2
stat64("/System/Volumes/Preboot/Cryptexes/OS/usr/lib/system/libquarantine.dylib\0", 0x7FF7BA414E30, 0x0) = -1 2
stat64("/usr/lib/system/libquarantine.dylib\0", 0x7FF7BA414E80, 0x0)     = -1 2
stat64("/usr/lib/system/libsystem_coreservices.dylib\0", 0x7FF7BA414E80, 0x0)    = -1 2
stat64("/System/Volumes/Preboot/Cryptexes/OS/usr/lib/system/libsystem_coreservices.dylib\0", 0x7FF7BA414E20, 0x0)    = -1 2
stat64("/usr/lib/system/libsystem_coreservices.dylib\0", 0x7FF7BA414E80, 0x0)    = -1 2
stat64("/usr/lib/system/libsystem_m.dylib\0", 0x7FF7BA414E80, 0x0)     = -1 2
stat64("/System/Volumes/Preboot/Cryptexes/OS/usr/lib/system/libsystem_m.dylib\0", 0x7FF7BA414E30, 0x0)   = -1 2
stat64("/usr/lib/system/libsystem_m.dylib\0", 0x7FF7BA414E80, 0x0)     = -1 2
stat64("/usr/lib/system/libmacho.dylib\0", 0x7FF7BA414E80, 0x0)    = -1 2
stat64("/System/Volumes/Preboot/Cryptexes/OS/usr/lib/system/libmacho.dylib\0", 0x7FF7BA414E30, 0x0)  = -1 2
stat64("/usr/lib/system/libmacho.dylib\0", 0x7FF7BA414E80, 0x0)    = -1 2
stat64("/usr/lib/system/libcommonCrypto.dylib\0", 0x7FF7BA414E80, 0x0)     = -1 2
stat64("/System/Volumes/Preboot/Cryptexes/OS/usr/lib/system/libcommonCrypto.dylib\0", 0x7FF7BA414E20, 0x0)     = -1 2
stat64("/usr/lib/system/libcommonCrypto.dylib\0", 0x7FF7BA414E80, 0x0)     = -1 2
stat64("/usr/lib/system/libunwind.dylib\0", 0x7FF7BA414E80, 0x0)     = -1 2
stat64("/System/Volumes/Preboot/Cryptexes/OS/usr/lib/system/libunwind.dylib\0", 0x7FF7BA414E30, 0x0)   = -1 2
stat64("/usr/lib/system/libunwind.dylib\0", 0x7FF7BA414E80, 0x0)     = -1 2
stat64("/usr/lib/liboah.dylib\0", 0x7FF7BA414E80, 0x0)     = -1 2
stat64("/System/Volumes/Preboot/Cryptexes/OS/usr/lib/liboah.dylib\0", 0x7FF7BA414E30, 0x0)     = -1 2
stat64("/usr/lib/liboah.dylib\0", 0x7FF7BA414E80, 0x0)     = -1 2
stat64("/usr/lib/system/libcopyfile.dylib\0", 0x7FF7BA414E80, 0x0)     = -1 2
stat64("/System/Volumes/Preboot/Cryptexes/OS/usr/lib/system/libcopyfile.dylib\0", 0x7FF7BA414E30, 0x0)   = -1 2
stat64("/usr/lib/system/libcopyfile.dylib\0", 0x7FF7BA414E80, 0x0)     = -1 2
stat64("/usr/lib/system/libcompiler_rt.dylib\0", 0x7FF7BA414E80, 0x0)    = -1 2
stat64("/System/Volumes/Preboot/Cryptexes/OS/usr/lib/system/libcompiler_rt.dylib\0", 0x7FF7BA414E30, 0x0)    = -1 2
stat64("/usr/lib/system/libcompiler_rt.dylib\0", 0x7FF7BA414E80, 0x0)    = -1 2
stat64("/usr/lib/system/libsystem_collections.dylib\0", 0x7FF7BA414E80, 0x0)     = -1 2
stat64("/System/Volumes/Preboot/Cryptexes/OS/usr/lib/system/libsystem_collections.dylib\0", 0x7FF7BA414E20, 0x0)     = -1 2
stat64("/usr/lib/system/libsystem_collections.dylib\0", 0x7FF7BA414E80, 0x0)     = -1 2
stat64("/usr/lib/system/libsystem_secinit.dylib\0", 0x7FF7BA414E80, 0x0)     = -1 2
stat64("/System/Volumes/Preboot/Cryptexes/OS/usr/lib/system/libsystem_secinit.dylib\0", 0x7FF7BA414E20, 0x0)     = -1 2
stat64("/usr/lib/system/libsystem_secinit.dylib\0", 0x7FF7BA414E80, 0x0)     = -1 2
stat64("/usr/lib/system/libremovefile.dylib\0", 0x7FF7BA414E80, 0x0)     = -1 2
stat64("/System/Volumes/Preboot/Cryptexes/OS/usr/lib/system/libremovefile.dylib\0", 0x7FF7BA414E30, 0x0) = -1 2
stat64("/usr/lib/system/libremovefile.dylib\0", 0x7FF7BA414E80, 0x0)     = -1 2
stat64("/usr/lib/system/libkeymgr.dylib\0", 0x7FF7BA414E80, 0x0)     = -1 2
stat64("/System/Volumes/Preboot/Cryptexes/OS/usr/lib/system/libkeymgr.dylib\0", 0x7FF7BA414E30, 0x0)   = -1 2
stat64("/usr/lib/system/libkeymgr.dylib\0", 0x7FF7BA414E80, 0x0)     = -1 2
stat64("/usr/lib/system/libsystem_dnssd.dylib\0", 0x7FF7BA414E80, 0x0)     = -1 2
stat64("/System/Volumes/Preboot/Cryptexes/OS/usr/lib/system/libsystem_dnssd.dylib\0", 0x7FF7BA414E20, 0x0)     = -1 2
stat64("/usr/lib/system/libsystem_dnssd.dylib\0", 0x7FF7BA414E80, 0x0)     = -1 2
stat64("/usr/lib/system/libcache.dylib\0", 0x7FF7BA414E80, 0x0)    = -1 2
stat64("/System/Volumes/Preboot/Cryptexes/OS/usr/lib/system/libcache.dylib\0", 0x7FF7BA414E30, 0x0)  = -1 2
stat64("/usr/lib/system/libcache.dylib\0", 0x7FF7BA414E80, 0x0)    = -1 2
stat64("/usr/lib/libSystem.B.dylib\0", 0x7FF7BA414E80, 0x0)    = -1 2
stat64("/System/Volumes/Preboot/Cryptexes/OS/usr/lib/libSystem.B.dylib\0", 0x7FF7BA414E30, 0x0)    = -1 2
stat64("/usr/lib/libSystem.B.dylib\0", 0x7FF7BA414E80, 0x0)    = -1 2
stat64("/usr/lib/system/libsystem_darwindirectory.dylib\0", 0x7FF7BA414E80, 0x0)     = -1 2
stat64("/System/Volumes/Preboot/Cryptexes/OS/usr/lib/system/libsystem_darwindirectory.dylib\0", 0x7FF7BA414E20, 0x0)     = -1 2
stat64("/usr/lib/system/libsystem_darwindirectory.dylib\0", 0x7FF7BA414E80, 0x0)     = -1 2
open("/dev/dtracehelper\0", 0x2, 0x0)    = 3 0
ioctl(0x3, 0x80086804, 0x7FF7BA416E18)     = 0 0
close(0x3)     = 0 0
open("/usr/local/Cellar/coreutils/9.4/bin/gls\0", 0x0, 0x0)    = 3 0
__mac_syscall(0x7FF819AD4E1B, 0x2, 0x7FF7BA4163D0)     = 0 0
map_with_linking_np(0x7FF7BA415FB0, 0x1, 0x7FF7BA415FE0)     = -1 22
close(0x3)     = 0 0
mprotect(0x105B08000, 0x4000, 0x1)     = 0 0
shared_region_check_np(0xFFFFFFFFFFFFFFFF, 0x0, 0x0)     = 0 0
mprotect(0x106100000, 0x40000, 0x1)    = 0 0
access("/AppleInternal/XBS/.isChrooted\0", 0x0, 0x0)     = -1 2
bsdthread_register(0x7FF819DC9B9C, 0x7FF819DC9B88, 0x2000)     = 1073742303 0
getpid(0x0, 0x0, 0x0)    = 49682 0
shm_open(0x7FF819C6CF42, 0x0, 0x19C6B388)    = 3 0
fstat64(0x3, 0x7FF7BA417340, 0x0)    = 0 0
mmap(0x0, 0x4000, 0x1, 0x40001, 0x3, 0x0)    = 0x105B1A000 0
close(0x3)     = 0 0
ioctl(0x2, 0x4004667A, 0x7FF7BA417404)     = 0 0
mprotect(0x105B23000, 0x1000, 0x0)     = 0 0
mprotect(0x105B2D000, 0x1000, 0x0)     = 0 0
mprotect(0x105B2E000, 0x1000, 0x0)     = 0 0
mprotect(0x105B38000, 0x1000, 0x0)     = 0 0
mprotect(0x105B1E000, 0x98, 0x1)     = 0 0
mprotect(0x105B1E000, 0x98, 0x3)     = 0 0
mprotect(0x105B1E000, 0x98, 0x1)     = 0 0
mprotect(0x105B39000, 0x1000, 0x1)     = 0 0
mprotect(0x105B3A000, 0x98, 0x1)     = 0 0
mprotect(0x105B3A000, 0x98, 0x3)     = 0 0
mprotect(0x105B3A000, 0x98, 0x1)     = 0 0
mprotect(0x105B1E000, 0x98, 0x3)     = 0 0
mprotect(0x105B1E000, 0x98, 0x1)     = 0 0
mprotect(0x105B39000, 0x1000, 0x3)     = 0 0
mprotect(0x105B39000, 0x1000, 0x1)     = 0 0
mprotect(0x106100000, 0x40000, 0x3)    = 0 0
mprotect(0x106100000, 0x40000, 0x1)    = 0 0
issetugid(0x0, 0x0, 0x0)     = 0 0
mprotect(0x106100000, 0x40000, 0x3)    = 0 0
getentropy(0x7FF7BA416C30, 0x20, 0x0)    = 0 0
mprotect(0x106100000, 0x40000, 0x1)    = 0 0
mprotect(0x106100000, 0x40000, 0x3)    = 0 0
mprotect(0x106100000, 0x40000, 0x1)    = 0 0
getattrlist("/usr/local/opt/coreutils/libexec/gnubin/ls\0", 0x7FF7BA4172E0, 0x7FF7BA4172F8)    = 0 0
access("/usr/local/Cellar/coreutils/9.4/bin\0", 0x4, 0x0)    = 0 0
open("/usr/local/Cellar/coreutils/9.4/bin\0", 0x0, 0x0)    = 3 0
fstat64(0x3, 0x7FAEECF042E0, 0x0)    = 0 0
csrctl(0x0, 0x7FF7BA41753C, 0x4)     = 0 0
fcntl(0x3, 0x32, 0x7FF7BA4171F0)     = 0 0
close(0x3)     = 0 0
open("/usr/local/Cellar/coreutils/9.4/bin/Info.plist\0", 0x0, 0x0)     = -1 2
proc_info(0x2, 0xC212, 0xD)    = 64 0
csops_audittoken(0xC212, 0x10, 0x7FF7BA417540)     = -1 22
dtrace: error on enabled probe ID 1741 (ID 573: syscall::sysctl:return): invalid kernel access in action #10 at DIF offset 28
dtrace: error on enabled probe ID 1741 (ID 573: syscall::sysctl:return): invalid kernel access in action #10 at DIF offset 28
csops(0xC212, 0x0, 0x7FF7BA4179A4)     = 0 0
mprotect(0x106100000, 0x40000, 0x3)    = 0 0
open_nocancel("/usr/share/locale/en_US.UTF-8/LC_COLLATE\0", 0x0, 0x0)    = 3 0
fcntl_nocancel(0x3, 0x3, 0x0)    = 0 0
getrlimit(0x1008, 0x7FF7BA417D10, 0x0)     = 0 0
fstat64(0x3, 0x7FF7BA417C88, 0x0)    = 0 0
dtrace: error on enabled probe ID 1714 (ID 961: syscall::read_nocancel:return): invalid kernel access in action #12 at DIF offset 68
close_nocancel(0x3)    = 0 0
open_nocancel("/usr/share/locale/en_US.UTF-8/LC_CTYPE\0", 0x0, 0x0)    = 3 0
fcntl_nocancel(0x3, 0x3, 0x0)    = 0 0
fstat64(0x3, 0x7FF7BA417DD0, 0x0)    = 0 0
fstat64(0x3, 0x7FF7BA417BD8, 0x0)    = 0 0
lseek(0x3, 0x0, 0x1)     = 0 0
lseek(0x3, 0x0, 0x0)     = 0 0
dtrace: error on enabled probe ID 1714 (ID 961: syscall::read_nocancel:return): invalid kernel access in action #12 at DIF offset 68
dtrace: error on enabled probe ID 1714 (ID 961: syscall::read_nocancel:return): invalid kernel access in action #12 at DIF offset 68
dtrace: error on enabled probe ID 1714 (ID 961: syscall::read_nocancel:return): invalid kernel access in action #12 at DIF offset 68
dtrace: error on enabled probe ID 1714 (ID 961: syscall::read_nocancel:return): invalid kernel access in action #12 at DIF offset 68
dtrace: error on enabled probe ID 1714 (ID 961: syscall::read_nocancel:return): invalid kernel access in action #12 at DIF offset 68
dtrace: error on enabled probe ID 1714 (ID 961: syscall::read_nocancel:return): invalid kernel access in action #12 at DIF offset 68
dtrace: error on enabled probe ID 1714 (ID 961: syscall::read_nocancel:return): invalid kernel access in action #12 at DIF offset 68
dtrace: error on enabled probe ID 1714 (ID 961: syscall::read_nocancel:return): invalid kernel access in action #12 at DIF offset 68
close_nocancel(0x3)    = 0 0
open_nocancel("/usr/share/locale/en_US.UTF-8/LC_MONETARY\0", 0x0, 0x0)     = 3 0
fstat64(0x3, 0x7FF7BA417DD8, 0x0)    = 0 0
dtrace: error on enabled probe ID 1714 (ID 961: syscall::read_nocancel:return): invalid kernel access in action #12 at DIF offset 68
close_nocancel(0x3)    = 0 0
open_nocancel("/usr/share/locale/en_US.UTF-8/LC_NUMERIC\0", 0x0, 0x0)    = 3 0
fstat64(0x3, 0x7FF7BA417DD8, 0x0)    = 0 0
dtrace: error on enabled probe ID 1714 (ID 961: syscall::read_nocancel:return): invalid kernel access in action #12 at DIF offset 68
close_nocancel(0x3)    = 0 0
open_nocancel("/usr/share/locale/en_US.UTF-8/LC_TIME\0", 0x0, 0x0)     = 3 0
fstat64(0x3, 0x7FF7BA417DD8, 0x0)    = 0 0
dtrace: error on enabled probe ID 1714 (ID 961: syscall::read_nocancel:return): invalid kernel access in action #12 at DIF offset 68
close_nocancel(0x3)    = 0 0
open_nocancel("/usr/share/locale/en_US.UTF-8/LC_MESSAGES/LC_MESSAGES\0", 0x0, 0x0)     = 3 0
fstat64(0x3, 0x7FF7BA417DD8, 0x0)    = 0 0
dtrace: error on enabled probe ID 1714 (ID 961: syscall::read_nocancel:return): invalid kernel access in action #12 at DIF offset 68
close_nocancel(0x3)    = 0 0
ioctl(0x1, 0x4004667A, 0x7FF7BA418324)     = 0 0
ioctl(0x1, 0x40087468, 0x7FF7BA4183F0)     = 0 0
open_nocancel(".\0", 0x1100004, 0x0)     = 3 0
dtrace: error on enabled probe ID 1741 (ID 573: syscall::sysctl:return): invalid kernel access in action #10 at DIF offset 28
dtrace: error on enabled probe ID 1741 (ID 573: syscall::sysctl:return): invalid kernel access in action #10 at DIF offset 28
fstatfs64(0x3, 0x7FF7BA417AB0, 0x0)    = 0 0
getdirentries64(0x3, 0x7FAEED80FC00, 0x2000)     = 568 0
close_nocancel(0x3)    = 0 0
sigprocmask(0x1, 0x0, 0x7FF7BA418350)    = 0x0 0
sigaltstack(0x0, 0x7FF7BA418340, 0x0)    = 0 0
fstat64(0x1, 0x7FF7BA416E58, 0x0)    = 0 0
ioctl(0x1, 0x4004667A, 0x7FF7BA416EA4)     = 0 0
dtrace: error on enabled probe ID 1712 (ID 963: syscall::write_nocancel:return): invalid kernel access in action #12 at DIF offset 68
dtrace: error on enabled probe ID 1712 (ID 963: syscall::write_nocancel:return): invalid kernel access in action #12 at DIF offset 68
close_nocancel(0x1)    = 0 0
close_nocancel(0x2)    = 0 0

troubleshooting

dtrace: system integrity protection is on

[!TIP]
* iMarlso: osx/system integrity protection

# csrutil disable
# or
# csrutil enable --without dtrace
# or
# csrutil enable --without dtrace --without debug

sar

netcat

[!NOTE|label:references:]
the netcat command in linux

check particular port

$ nc -zv 127.0.0.1 22
Connection to 127.0.0.1 port 22 [tcp/ssh] succeeded!

check ports in range

$ nc -znv -w 1 127.0.0.1 20-30
nc: connectx to 127.0.0.1 port 20 (tcp) failed: Connection refused
nc: connectx to 127.0.0.1 port 21 (tcp) failed: Connection refused
Connection to 127.0.0.1 port 22 [tcp/*] succeeded!
nc: connectx to 127.0.0.1 port 23 (tcp) failed: Connection refused
nc: connectx to 127.0.0.1 port 24 (tcp) failed: Connection refused
nc: connectx to 127.0.0.1 port 25 (tcp) failed: Connection refused
nc: connectx to 127.0.0.1 port 26 (tcp) failed: Connection refused
nc: connectx to 127.0.0.1 port 27 (tcp) failed: Connection refused
nc: connectx to 127.0.0.1 port 28 (tcp) failed: Connection refused

running simple web server

$ cat > index.html <<<EOF
<!DOCTYPE html>
<html>
    <head>
        <title>Simple Netcat Server</title>
    </head>
    <body>
        <h1>Welcome to simple netcat server!<h1>
    </body>
    </body>
<html>
EOF

$ echo -e "HTTP/1.1 200 OK\n\n$(cat index.html)" | nc -l 1234

or getting more

$ while true; do echo -e "HTTP/1.1 200 OK\n\n$(cat index.html)" | nc -l -w 1 1234; done
GET / HTTP/1.1
Host: localhost:1234
Connection: keep-alive
sec-ch-ua: "Chromium";v="110", "Not A(Brand";v="24", "Google Chrome";v="110"
sec-ch-ua-mobile: ?0
sec-ch-ua-platform: "macOS"
Upgrade-Insecure-Requests: 1
User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/110.0.0.0 Safari/537.36
Accept: text/html,application/xhtml+xml,application/xml;q=0.9,image/avif,image/webp,image/apng,*/*;q=0.8,application/signed-exchange;v=b3;q=0.7
Sec-Fetch-Site: none
Sec-Fetch-Mode: navigate
Sec-Fetch-User: ?1
Sec-Fetch-Dest: document
Accept-Encoding: gzip, deflate, br
Accept-Language: en,zh-CN;q=0.9,zh;q=0.8,en-US;q=0.7

GET /favicon.ico HTTP/1.1
Host: localhost:1234
Connection: keep-alive
sec-ch-ua: "Chromium";v="110", "Not A(Brand";v="24", "Google Chrome";v="110"
sec-ch-ua-mobile: ?0
User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/110.0.0.0 Safari/537.36
sec-ch-ua-platform: "macOS"
Accept: image/avif,image/webp,image/apng,image/svg+xml,image/*,*/*;q=0.8
Sec-Fetch-Site: same-origin
Sec-Fetch-Mode: no-cors
Sec-Fetch-Dest: image
Referer: http://localhost:1234/
Accept-Encoding: gzip, deflate, br
Accept-Language: en,zh-CN;q=0.9,zh;q=0.8,en-US;q=0.7
...

reverse proxy with netcat

emulating netcat -e

$ mkfifo foo ; nc -lk 2600 0<foo | /bin/bash 1>foo

`ip`

$ ip addr show | sed -nE "s/inet\s(.*)\/[0-9]+.*\s(\w+)/\2 \1/p"
  lo0 127.0.0.1
  en0 192.168.1.71

# for linux
$ ip addr show | sed -nE "s/inet\s(.*)\/[0-9]+.*\s(\w+)/\2 \1/p" | column -to ' => '
lo0 => 127.0.0.1
en0 => 192.168.1.71

datadog

others

[!NOTE|label:references:]
完全指南：在 Linux 中如何打印和管理打印机
440+ 个免费的编程 & 计算机科学的在线课程
在 Linux 上用 DNS 实现简单的负载均衡
Python 字节码介绍

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Last updated 7 days ago

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