# tricky * [process bar](#process-bar) * [with dot `.`](#with-dot-) * [with `▉ ▎ ▌ ▊`](#with-▉-▎-▌-▊) * [with `[###----]`](#with-----) * [with `|\|/`](#with-\\) * [Integralist/python progress bar.py](#integralistpython-progress-barpy) * [spinner](#spinner) * [Braille Patterns](#braille-patterns) * [others](#others) * [bash script](#bash-script) * [save & restore screen](#save--restore-screen) * [`tput`](#tput) * [`echo`](#echo) * [terminfo escape sequences](#terminfo-escape-sequences) * [`tput`](#tput-1) * [reset terminal](#reset-terminal) * [clear screen](#clear-screen) * [show term](#show-term) * [show terminal width](#show-terminal-width) * [customized colorful output](#customized-colorful-output) * [`Operation not permitted`](#operation-not-permitted) * [array](#array) * [differences in bash parameter calls](#differences-in-bash-parameter-calls) * [wildcard expansion](#wildcard-expansion) ### process bar {% hint style="info" %} > reference: > > * [How to add a progress bar to a shell script?](https://stackoverflow.com/questions/238073/how-to-add-a-progress-bar-to-a-shell-script) > {% endhint %} #### with dot `.` > reference: > > * [colorful output : `c()`](https://raw.githubusercontent.com/ppo/bash-colors/master/bash-colors.sh) > * [`c()` can be also found in .marslorc](https://github.com/marslo/mylinux/blob/master/confs/home/.marslo/.marslorc#L138) ```bash while true; do (( i++ == 0 )) && printf $(c sY)%-6s$(c) 'waiting ...' || printf $(c sY)%s$(c) '.' sleep 1 done ``` ![waiting bar with dot](/files/-Me-690MnajXAuX6GeD5) #### [with `▉ ▎ ▌ ▊`](https://stackoverflow.com/a/65532561/2940319) > another: > > * [A progress bar for the shell](https://ownyourbits.com/2017/07/16/a-progress-bar-for-the-shell/) ```bash # main function designed for quickly copying to another program progressBar() { Bar="" # Progress Bar / Volume level Len=25 # Length of Progress Bar / Volume level Div=4 # Divisor into Volume for # of blocks Fill="▒" # Fill up to $Len Arr=( "▉" "▎" "▌" "▊" ) # UTF-8 left blocks: 7/8, 1/4, 1/2, 3/4 FullBlock=$((${1} / Div)) # Number of full blocks PartBlock=$((${1} % Div)) # Size of partial block (array index) while [[ $FullBlock -gt 0 ]]; do Bar="$Bar${Arr[0]}" # Add 1 full block into Progress Bar (( FullBlock-- )) # Decrement full blocks counter done # if remainder zero no partial block, else append character from array if [[ $PartBlock -gt 0 ]]; then Bar="$Bar${Arr[$PartBlock]}"; fi # Pad Progress Bar with fill character while [[ "${#Bar}" -lt "$Len" ]]; do Bar="$Bar$Fill"; done echo progress : "$1 $Bar" exit 0 # Remove this line when copying into program } # progressBar Main () { tput civis # Turn off cursor for ((i=0; i<=100; i++)); do CurrLevel=$(progressBar "$i") # Generate progress bar 0 to 100 echo -ne "$CurrLevel"\\r # Reprint overtop same line sleep .04 done echo -e \\n # Advance line to keep last progress echo "$0 Done" tput cnorm # Turn cursor back on } # main Main "$@" ``` ![progress bar with ▎▌ ▊ ▉](/files/-Me-690OK5KzkAw1TY7M) #### [with `[###----]`](https://stackoverflow.com/a/64932365/2940319) > another solution: > > * [fearside/ProgressBar](https://github.com/fearside/ProgressBar/blob/master/progressbar.sh) ```bash BAR='##############################' FILL='------------------------------' totalLines=100 barLen=30 count=0 while [ ${count} -lt ${totalLines} ]; do # update progress bar count=$(( ${count}+ 1 )) percent=$(( (${count} * 100 / ${totalLines} * 100)/ 100 )) i=$(( ${percent} * ${barLen} / 100 )) echo -ne "\r[${BAR:0:$i}${FILL:$i:barLen}] ${count}/${totalLines} (${percent}%)" sleep .1 done ``` ![progress bar with \[###----\]](/files/-Me-690PtMwLlWkac2yc) #### [with `|\|/`](https://stackoverflow.com/a/3330834/2940319) ```bash while :; do for s in / - \\ \| do printf "\r$s" sleep .1 done done ``` ![progress bar with |\\|/](/files/-Me-690QRz5MJpZmiasw) #### [Integralist/python progress bar.py](https://gist.github.com/Integralist/01aed051251476c4bd6daa4b076eb23a) ### spinner > \[!TIP|label:check more:] > > * [\* iMarslo: gist/\_spinner.md](https://gist.github.com/marslo/3f4b1eae28902394ad3201d1b5ea5537) #### Braille Patterns > \[!NOTE|label:references:] > > * [unicode - Braille Patterns](https://symbl.cc/en/unicode/blocks/braille-patterns/) > > * [wikipedia - Braille Patterns](https://en.wikipedia.org/wiki/Braille_Patterns) > > * [SamEureka/spinner.sh](https://gist.github.com/SamEureka/3e61942d37256550b40d0ffe75bc22c4) > > * [Braille Patterns - U2800.pdf](https://unicode.org/charts/PDF/U2800.pdf) > > > Braille 8 dot Cell Numbering > > > > ``` > > +---+---+ > > | 1 | 4 | > > +---+---+ > > | 2 | 5 | > > +---+---+ > > | 3 | 6 | > > +---+---+ > > | 7 | 8 | > > +---+---+ > > ``` **4-dots** | UNICODE | ICON | HTML ENCODING | COMMENTS | | :-----: | :--: | :-----------: | -------- | | `28C4` | ⣄ | `⣄` | `378` | | `28C6` | ⣆ | `⣆` | `2378` | | `2847` | ⡇ | `⡇` | `1237` | | `280F` | ⠏ | `⠏` | `1234` | | `280B` | ⠋ | `⠋` | `124` | | `2839` | ⠹ | `⠹` | `1456` | | `28B8` | ⢸ | `⢸` | `4568` | | `28F0` | ⣰ | `⣰` | `5678` | | `28E0` | ⣠ | `⣠` | `678` | [![4-dots](https://github.com/marslo/iDevOps/raw/master/screenshot/spinner/spinner-8.gif)](https://github.com/marslo/iDevOps/raw/master/screenshot/spinner/spinner-8.gif) ```bash local spinner=( '⣄' '⣆' '⡇' '⠏' '⠋' '⠹' '⢸' '⣰' '⣠' ) local spinner=( "$(c Rs)⣄$(c)" # red "$(c Ys)⣆$(c)" # yellow "$(c Gs)⡇$(c)" # green "$(c Bs)⠏$(c)" # blue "$(c Ms)⠋$(c)" # magenta "$(c Ys)⠹$(c)" # yellow "$(c Gs)⢸$(c)" # green "$(c Bs)⣰$(c)" # blue "$(c Ms)⣠$(c)" # magenta ) ``` **7-dots** | UNICODE | ICON | HTML ENCODING | COMMENTS | | :-----: | :--: | :-----------: | --------- | | `28FE` | ⣾ | `⣾` | `2345678` | | `28FD` | ⣽ | `⣽` | `1345678` | | `28FB` | ⣻ | `⣻` | `1245678` | | `28BF` | ⢿ | `⢿` | `1234568` | | `287F` | ⡿ | `⡿` | `1234567` | | `28DF` | ⣟ | `⣟` | `1234578` | | `28EF` | ⣯ | `⣯` | `1234678` | | `28F7` | ⣷ | `⣷` | `1235678` | [![7-dots](https://github.com/marslo/iDevOps/raw/master/screenshot/spinner/spinner-5.gif)](https://github.com/marslo/iDevOps/raw/master/screenshot/spinner/spinner-5.gif) ```bash local spinner=( '⣾' '⣽' '⣻' '⢿' '⡿' '⣟' '⣯' '⣷' '⣿' ) local spinner=( "$(c Rs)⣾$(c)" # red "$(c Ys)⣽$(c)" # yellow "$(c Gs)⣻$(c)" # green "$(c Cs)⢿$(c)" # cyan "$(c Rs)⡿$(c)" # red "$(c Ys)⣟$(c)" # yellow "$(c Gs)⣯$(c)" # green "$(c Cs)⣷$(c)" # cyan ) ``` **1-dot** [![1-dot](https://github.com/marslo/iDevOps/raw/master/screenshot/spinner/spinner-6.gif)](https://github.com/marslo/iDevOps/raw/master/screenshot/spinner/spinner-6.gif) ```bash local spinner=( '⠁' '⠂' '⠄' '⡀' '⢀' '⠠' '⠐' '⠈' ) local spinner=( "$(c Ys)⠁$(c)" # yellow "$(c Gs)⠂$(c)" # green "$(c Cs)⠄$(c)" # cyan "$(c Ms)⡀$(c)" # magenta "$(c Ys)⢀$(c)" # yellow "$(c Gs)⠠$(c)" # green "$(c Cs)⠐$(c)" # cyan "$(c Ms)⠈$(c)" # magenta ) ``` #### others [![](https://github.com/marslo/iDevOps/raw/master/screenshot/spinner/spinner-2.gif)](https://github.com/marslo/iDevOps/raw/master/screenshot/spinner/spinner-2.gif) ```bash local spinner=( '∙∙∙∙∙' '●∙∙∙∙' '∙●∙∙∙' '∙∙●∙∙' '∙∙∙●∙' '∙∙∙∙●' ) local spinner=( "∙∙∙∙∙" "$(c Ys)●$(c)∙∙∙∙" # yellow "∙$(c Gs)●$(c)∙∙∙" # green "∙∙$(c Cs)●$(c)∙∙" # cyan "∙∙∙$(c Bs)●$(c)∙" # blue "∙∙∙∙$(c Ms)●$(c)" # magenta ) local spinner=( "$(c Rs)∙∙∙∙∙$(c)" # red "$(c Ys)●∙∙∙∙$(c)" # yellow "$(c Gs)∙●∙∙∙$(c)" # green "$(c Cs)∙∙●∙∙$(c)" # cyan "$(c Bs)∙∙∙●∙$(c)" # blue "$(c Ms)∙∙∙∙●$(c)" # magenta ) ``` #### bash script [**with stdout**](https://gist.github.com/marslo/3f4b1eae28902394ad3201d1b5ea5537#file-spinner-with-stdout-sh) > \[!TIP|label:use case:] > > * [\* iMarslo: ccm.sh - copilot commit message](https://github.com/marslo/dotfiles/blob/main/.marslo/bin/ccm.sh) ```bash #!/usr/bin/env bash # credit: https://github.com/ppo/bash-colors # shellcheck disable=SC2015,SC2059 c() { [ $# == 0 ] && printf "\e[0m" || printf "$1" | sed 's/\(.\)/\1;/g;s/\([SDIUFNHT]\)/2\1/g;s/\([KRGYBMCW]\)/3\1/g;s/\([krgybmcw]\)/4\1/g;y/SDIUFNHTsdiufnhtKRGYBMCWkrgybmcw/12345789123457890123456701234567/;s/^\(.*\);$/\\e[\1m/g'; } # capture ctrl-c to exit the sub-process # return the sub-process stdout ( to external variable ) function withSpinner() { local msg="$1"; shift local __resultvar="$1"; shift local spinner=( "$(c Rs)⣾$(c)" "$(c Ys)⣽$(c)" "$(c Gs)⣻$(c)" "$(c Cs)⢿$(c)" "$(c Rs)⡿$(c)" "$(c Ys)⣟$(c)" "$(c Gs)⣯$(c)" "$(c Cs)⣷$(c)" ) local frame=0 local output local cmdPid local pgid='' local interrupted=0 # define the cursor recovery function restoreCursor() { printf "\033[?25h" >&2; } # make sure that any exit restores the cursor trap 'restoreCursor' EXIT # hide cursor printf "\033[?25l" >&2 printf "%s " "$msg" >&2 set -m trap 'interrupted=1; [ -n "$pgid" ] && kill -TERM -- -$pgid 2>/dev/null' INT # use file descriptor to capture output local tmpout tmpout=$(mktemp) exec 3<> "${tmpout}" # shellcheck disable=SC2031,SC2030 output="$( { # execute command and redirect output to file descriptor 3 "$@" >&3 2>/dev/null & cmdPid=$! pgid=$(ps -o pgid= "$cmdPid" | tr -d ' ') # update the spinner while the command is running while kill -0 "$cmdPid" 2>/dev/null && (( interrupted == 0 )); do printf "\r\033[K%s %b" "${msg}" "${spinner[frame]}" >&2 ((frame = (frame + 1) % ${#spinner[@]})) sleep 0.08 done wait "$cmdPid" 2>/dev/null # show the captured content cat "${tmpout}" } )" # clean the temporary file exec 3>&- rm -f "${tmpout}" # \r : beginning of line # \033[K : clear current position to end of line # shellcheck disable=SC2031 if (( interrupted )); then printf "\r\033[K\033[31m✗\033[0m Interrupted!\033[K\n" >&2 [ -n "${pgid}" ] && kill -TERM -- -"${pgid}" 2>/dev/null else # or using `printf "\r" >&2` directly without sub-progress status output printf "\r\033[K\033[32m✓\033[0m Done!\033[K\n" >&2 fi # assign the result to an external variable printf -v "$__resultvar" "%s" "$output" } function main() { # shellcheck disable=SC2155 local tmpfile=$(mktemp) trap 'rm -f "${tmpfile}"' EXIT local response withSpinner "Loading..." response \ curl -s https:// ... # check curl output echo "${response}" } main "$@" # vim:tabstop=2:softtabstop=2:shiftwidth=2:expandtab:filetype=sh: ``` [**with exitcode**](https://gist.github.com/marslo/3f4b1eae28902394ad3201d1b5ea5537#file-spinner-with-exitcode-sh) ```bash #!/usr/bin/env bash # credit: https://github.com/ppo/bash-colors # shellcheck disable=SC2015,SC2059 c() { [ $# == 0 ] && printf "\e[0m" || printf "$1" | sed 's/\(.\)/\1;/g;s/\([SDIUFNHT]\)/2\1/g;s/\([KRGYBMCW]\)/3\1/g;s/\([krgybmcw]\)/4\1/g;y/SDIUFNHTsdiufnhtKRGYBMCWkrgybmcw/12345789123457890123456701234567/;s/^\(.*\);$/\\e[\1m/g'; } # capture ctrl-c to exit the sub-process function withSpinner() { local msg="$1"; shift local __resultvar="$1"; shift local spinner=( "$(c Rs)⣄$(c)" "$(c Ys)⣆$(c)" "$(c Gs)⡇$(c)" "$(c Bs)⠏$(c)" "$(c Ms)⠋$(c)" "$(c Ys)⠹$(c)" "$(c Gs)⢸$(c)" "$(c Bs)⣰$(c)" "$(c Ms)⣠$(c)" ) local frame=0 local output local cmdPid local pgid="" local interrupted=0 # explicit recovery cursor function restoreCursor() { printf "\033[?25h" >&2; } # ensure that any exit restores the cursor. trap 'restoreCursor' EXIT # hide cursor printf "\033[?25l" >&2 printf "%s " "${msg}" >&2 set -m trap 'interrupted=1; [ -n "${pgid}" ] && kill -TERM -- -${pgid} 2>/dev/null' INT # shellcheck disable=SC2034,SC2030 output="$( { "$@" 2>/dev/null & cmdPid=$! pgid=$(ps -o pgid= ${cmdPid} | tr -d ' ') echo "${pgid}" > "${tmpfile}" while kill -0 "$cmdPid" 2>/dev/null && (( interrupted == 0 )); do printf "\r\033[K%s %b" "${msg}" "${spinner[frame]}" >&2 ((frame = (frame + 1) % ${#spinner[@]})) sleep 0.1 done wait "${cmdPid}" 2>/dev/null } )" # \r : beginning of line # \033[K : clear current position to end of line if (( interrupted )); then printf "\r\033[K\033[31m✗\033[0m Interrupted!\033[K\n" >&2 # shellcheck disable=SC2031 [ -n "${pgid}" ] && kill -TERM -- -"${pgid}" 2>/dev/null else printf "\r\033[K\033[32m✓\033[0m Done!\033[K\n" >&2 fi # a separate recovery cursor is no longer required because the exit trap is handled } # main function function main() { tmpfile=$(mktemp) trap 'rm -f "${tmpfile}"' EXIT withSpinner "Loading..." result sleep 5 echo "Exit code: $?" } main "$@" # vim:tabstop=2:softtabstop=2:shiftwidth=2:expandtab:filetype=sh: ``` ### save & restore screen {% hint style="info" %} > reference > > * [Terminal codes (ANSI/VT100) introduction](https://wiki.bash-hackers.org/scripting/terminalcodes) > {% endhint %} #### `tput` * clear ```bash $ tput smcup ``` * restore ```bash $ tput rmcup ``` #### `echo` * save ```bash $ echo -e '\033[?47h' ``` * restore ```bash $ echo -e '\033[?47l' ``` ### terminfo escape sequences ```bash $ infocmp ... colors#256, cols#80, it#8, lines#24, pairs#32767, bel=^G, blink=\E[5m, bold=\E[1m, cbt=\E[Z, civis=\E[?25l, clear=\E[H\E[2J, cnorm=\E[?12l\E[?25h, cr=^M, ... ``` ### `tput` #### reset terminal > \[!NOTE] > > * [Shell does not show typed-in commands, what do I do to fix it?](https://askubuntu.com/a/1238357/92979) ```bash $ reset # or $ stty sane ``` #### clear screen ```bash $ tput home # or $ tput cup %py %px # or $ tput cup %py %px >/dev/null ``` #### show term ```bash $ tput color ``` #### show terminal width ```bash $ tput cols ``` #### [customized colorful output](https://unix.stackexchange.com/a/163781/29178) {% hint style="info" %} > references: > > * [imarslo: highlight output](https://github.com/marslo/ibook/blob/marslo/docs/cheatsheet/tricky.html#highlight-output) > {% endhint %} ```bash $ export GREP_COLORS="sl=0;33;49:ms=1;34;49" $ find /etc/ -type f | head | grep --color=always '^\|[^/]*$' ``` ![customized color output](/files/-Me-690RI_6f-diE_SEe) ### `Operation not permitted` > \[!NOTE|label:references:] > > * [How to Fix 'rm: cannot remove '/etc/resolv.conf': Operation not permitted'](https://support.tools/post/fix-stuck-resolv-conf/) > * [Can not edit resolv.conf](https://askubuntu.com/a/1276691/92979) > * [Un-removable /etc/resolv.conf](https://askubuntu.com/questions/125847/un-removable-etc-resolv-conf) > * mac equivalent > * [chflags](https://ss64.com/mac/chflags.html) > * `/bin/ls -lO` > > ```bash > $ /bin/ls -lO > total 288 > -rwxr-xr-x@ 1 marslo staff compressed,dataless 1116834851 Feb 21 17:00 Ubuntu2204-221101.AppxBundle > ``` ```bash $ sudo lsattr /etc/resolv.conf ----i-------------- /etc/resolv.conf $ sudo rm -rf /etc/resolv.conf rm: cannot remove '/etc/resolv.conf': Operation not permitted # solution $ sudo chattr -i /etc/resolv.conf $ sudo lsattr /etc/resolv.conf ------------------- /etc/resolv.conf $ sudo mv /etc/resolv.conf{,.bak} # revert back $ sudo chattr +i /etc/resolv.conf $ sudo lsattr /etc/resolv.conf ----i-------------- /etc/resolv.conf ``` ### array #### differences in bash parameter calls > \[!NOTE:label:thinking:]\ > I got a issue with/without `eval` commands like: > > > ```bash > > local fdOpt="--type f --hidden --follow --unrestricted --ignore-file $HOME/.fdignore" > > local ignores=( > > '*.pem' '*.p12' > > '*.png' '*.jpg' '*.jpeg' '*.gif' '*.svg' > > '*.zip' '*.tar' '*.gz' '*.bz2' '*.xz' '*.7z' '*.rar' > > 'Music' '.target_book' '_book' 'OneDrive*' > > ) > > while read -r pattern; do fdOpt+=" --exclude '${pattern}'"; done <<< "$(printf '%s\n' "${ignores[@]}")" > > fdOpt+=' --exec-batch ls -t' > > ``` > > * the `--exclude` options are not passed correctly when using : > > > ```bash > > fd . ${fdOpt} | fzf ${foption} --bind="enter:become(${VIM} {+})" > > ``` > > * but it works when using `eval` : > > > ```bash > > eval "fd . ${fdOpt}" | fzf ${foption} --bind="enter:become(${VIM} {+})" > > ``` > \[!TIP|label:tips:] > > > since `fdOpt` is **a single string** (containing multiple arguments), Bash treats it as **one single argument** when passed to `fd`. This leads to the following issues: > > > > `--exclude '*.png'` is treated as **one single argument**, rather than **two separate ones**: `--exclude` and `'*.png'`; > > > > As a result, fd cannot correctly interpret the glob pattern and treats it as a literal string;\ > > Therefore, `--exclude '*.png'` does not actually exclude anything. > > recommend using arrays to store multiple arguments and then pass them to the command. > > > ```bash > > # array > > local -a fdArgs=(--type f --hidden --follow --unrestricted --ignore-file "${HOME}/.fdignore") > > local ignores=( > > '*.pem' '*.p12' > > '*.png' '*.jpg' '*.jpeg' '*.gif' '*.svg' > > '*.zip' '*.tar' '*.gz' '*.bz2' '*.xz' '*.7z' '*.rar' > > 'Music' '.target_book' '_book' 'OneDrive*' > > ) > > > > for pattern in "${ignores[@]}"; do fdArgs+=(--exclude "${pattern}"); done > > fdArgs+=(--exec-batch ls -t) > > > > # array call > > # +------------+ > > fd . "${fdArgs[@]}" | fzf ${foption} --bind="enter:become(${VIM} {+})" > > ``` > > details: | FORM | WORKS? | REASON | | ---------------------- | -------------------- | ------------------------------------------------------------------ | | `fd . ${fdOpt}` | ❌ No | ${fdOpt} is a single string; arguments are not properly split | | `eval "fd . ${fdOpt}"` | ✅ Yes | Bash re-splits the command string before execution, but it’s risky | | `fd . "${fdArgs[@]}"` | ✅✅ Yes (Recommended) | Uses an argument array — most recommended, safe, and clean | | METHOD | ARGUMENT PARSING | SAFETY | WILDCARD EXPANSION | RECOMMENDED USE CASE | | ------------- | ---------------------------------------- | ------ | ------------------- | ---------------------------------------------------------------- | | `$cmd` | ❌ Incorrect, treated as a single command | ❌ Low | ❌ No | Avoid using | | `eval "$cmd"` | ✅ Correctly splits arguments | ⚠️ Low | ✅ Yes | Quick testing or executing ad-hoc command strings | | `"${cmd[@]}"` | ✅ Correct and safe argument passing | ✅ High | ❌ No (no expansion) | Recommended for building command argument lists programmatically | ```bash $ ls bar.bak bar.txt demo.sh foo.log foo.txt $ bash demo.sh → Running: echo Listing *.txt with excludes: --exclude '*.log' --exclude '*.bak' Listing bar.txt foo.txt with excludes: --exclude '*.log' --exclude '*.bak' # +-------------+ # *.txt got expanded → Running with eval: echo Listing *.txt with excludes: --exclude '*.log' --exclude '*.bak' Listing bar.txt foo.txt with excludes: --exclude *.log --exclude *.bak # +-------------+ # *.txt got expanded → Running with array: echo Listing *.txt with excludes: --exclude *.log --exclude *.bak Listing *.txt with excludes: --exclude *.log --exclude *.bak ``` ```bash $ cat -c demo.sh #!/usr/bin/env bash set -euo pipefail function plainString() { local cmd="echo Listing *.txt with excludes: --exclude '*.log' --exclude '*.bak'" echo "→ Running: $cmd" $cmd } function evalString() { local cmd="echo Listing *.txt with excludes: --exclude '*.log' --exclude '*.bak'" echo "→ Running with eval: $cmd" eval "$cmd" } function arrayCall() { local -a cmd=("echo" "Listing" "*.txt" "with" "excludes:" "--exclude" "*.log" "--exclude" "*.bak") echo "→ Running with array: ${cmd[*]}" "${cmd[@]}" } plainString echo '' evalString echo '' arrayCall # vim:tabstop=2:softtabstop=2:shiftwidth=2:expandtab:filetype=sh: ``` #### wildcard expansion | METHOD | WILDCARD EXPANDED? | EXPLANATION | | --------------------- | ------------------ | -------------------------------------------------------------- | | `eval "echo *.txt"` | ✅ Yes | Shell expands the wildcard during evaluation | | `eval "echo '*.txt'"` | ❌ No | `'*.txt'` is a quoted string literal, not subject to expansion | | `"${arr[@]}"` | ❌ No | Arguments are passed as literal strings, no globbing applied | --- # Agent Instructions: Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter: ``` GET https://imarslo.gitbook.io/book/basic/util/tricky.md?ask= ``` The question should be specific, self-contained, and written in natural language. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.