• oneline commands
  • cat and EOF
  • while read from input
  • tail and timestamp
  • backup multiple files
  • ssh
  • find and tar
  • find and rename
  • find and sort
  • find and copy
  • download and extract
  • mirror website
  • kubectl apply from stdin
  • show 256 colors
  • rm and exclude
  • split file to equal size
• sync mirror
• get all declare
  • print env
• using string as variable name
• <<<, < <(..)
  • < <(..) && > >(..)
• parameter substitution
  • arguments substitution
  • quotas
• string manipulations
• compound comparison
  • SC2155
  • SC2155
  • escape code
• echo
  • echo var name from variable
  • echo var name
• ls
• bash completion
  • osx
  • linux
  • completion for alias
  • troubleshooting
• tricky
  • alias for sudo
  • get md5sum
  • env
  • shortcuts
  • man

oneline commands

[!TIP]

• iMarslo : kubernetes - oneline cmd
• johnnypea/useful-one-liners.sh
• ITT: Post useful shell aliases/functions
• Post your handy self made command line utilities

cat and EOF

[!NOTE|label:references:]

• Chapter 19. Here Documents
• bash Heredoc
  • using heredoc with ssh

    ssh -T user@host.com << EOF
    echo "The current local working directory is: $PWD"
    echo "The current remote working directory is: \$PWD"
    EOF
    

• * POSIX.1 states

  ...an operand naming a file can be specified as '-', which means to use the standard input instead of a named file ....
  

• kubectl apply from stdin

  [!NOTE|label:references:]

  • Need some explaination of kubectl stdin and pipe

  $ cat << 'EOF' | kubectl apply -f -
  ...
  ...
  EOF
  
  # or
  $ kubectl apply -f - << EOF
  ...
  ...
  EOF
  

• git apply from stdin

  $ cat >> 'EOF' | git apply --inaccurate-eof --ignore-whitespace
  ...
  ...
  EOF
  
  # or
  $ git apply --inaccurate-eof --ignore-whitespace --stat << 'EOF'
  ...
  ...
  EOF
   install |    6 ++----
   1 file changed, 2 insertions(+), 4 deletions(-)
  

• git apply from clipboard

  [!NOTE|label:references:]

  • Pipe (a patch in my clipboard) to git apply?

  $ pbpaste | git apply
  
  $ xsel --clipboard --input | git apply
  # or
  $ xclip -selection clipboard -o | git apply
  

• patch from stdin

  [!NOTE|label:references:]

  • How can I run patch through a heredoc in bash?

  $ patch --dry-run --ignore-whitespace << 'EOF'
  ...
  ...
  EOF
  

while read from input

[!NOTE|label:references:]

• How to use a shell command to only show the first column and last column in a text file?

$ while IFS=\| read -r col1 col2; do echo ">> $col1 .. $col2 <<"; done <<\INPUT
  a|b
  INPUT
>> a .. b <<

tail and timestamp

$ tail -f file | while read line; do echo -n $(date -u -Ins); echo -e "\t$line"; done

backup multiple files

$ cp -bfS.bak filename filename

ssh

• compress and ssh and extract

  $ tar cf - . | ssh elsewhere tar xf - -C /other/dir
  
  # or: https://www.commandlinefu.com/commands/view/4034/copy-a-folder-tree-through-ssh-using-compression-no-temporary-files
  $ ssh <host> 'tar -cz /<folder>/<subfolder>' | tar -xvz
  

• tips

  [!NOTE|label:references:]

  • How can I copy multiple files over scp in one command?

  # tips
  $ tar cfz - . | ssh otherhost "cd /mydir; tar xvzf -"
  
  # or: https://www.commandlinefu.com/commands/view/1629/pack-up-some-files-into-a-tarball-on-a-remote-server-without-writing-to-the-local-filesystem
  $ tar -czf - * | ssh example.com "cat > files.tar.gz"
  
  # the z-flag to tar does compression. Or you can use -C to ssh:
  $ tar cf - . | ssh -C otherhost "cd /mydir; tar xvf -"
  

find and tar

$ find . -name builds -prune -o -type f -print | tar czf ~/m.tar.gz --files-from -

# or find with maxdepth
$ find . -type f -name "config.xml" -maxdepth 2 -prune -print | tar czf ~/config.xml.130.tar.gz --files-from -

# find with special name
$ find . -name config\.xml -type f -print | tar czf ~/m.tar.gz --files-from -

# and ssh and extract
$ tar cf - . | ssh -C otherhost "cd /mydir; tar xvf -"

• for JENKINS_HOME

  • backup all config.xml in JENKINS_HOME

    $ find ${JENKINS_HOME}/jobs \
           -maxdepth 2 \
           -name config\.xml \
           -type f -print |
      tar czf ~/config.xml.tar.gz --files-from -
    

  • back build history

    $ find ${JENKINS_HOME}/jobs \
           -name builds \
           -prune -o \
           -type f \
           -print |
      tar czf ~/m.tar.gz --files-from -
    

• advanced ls

  $ find $PWD -maxdepth 1 -printf '%.5m %10M %#9u:%-9g %#5U:%-5G [%AD | %TD | %CD] [%Y] %p\n'
  
  # or
  $ find $PWD -maxdepth 1 -printf '%.5m %10M %#9u:%-9g %#5U:%-5G [%AD | %TD | %CD] [%Y] %p\n' | sort -rgbS 50%
  

• tar and ssh

  [!TIP|label:references:]

  • * iMarslo: ssh and tar
    • copy multiple files to remote server
    • tar all and extra in remote
    • copy local file content into remote

  $ tar czv file1 file2 file3 | ssh user@host 'tar xzv -C /target/dir'
  

• recursively unrar into dir containing archive

  $ find . -name '*.rar' -execdir unrar e {} \;
  

find and rename

$ find -iname "*.sh" -exec rename "s/.sh$/.shell/" {} \; -print

find and sort

• via timestamp

  [!NOTE]

  • How to Find and Sort Files Based on Modification Date and Time in Linux

    $ find . -type f -printf "\n%AD %AT %p" | head -n 11 | sort -k1.8n -k1.1nr -k1
    # or
    $ find . -type f -printf "\n%Tm/%Td/%TY %TT %p" | sort -k1.8n -k1.1nr -k1
    

  • * iMarslo : find printf
  • * printf time formats

    $ find . -printf "%T<format>\n"
    

  • sort by datetime format in bash
  • how to sort file by DD-MM-YYYY dates
  • Sort logs by date field in bash

  # via %T+
  $ find ~/.marslo -type f -printf "%10T+ | %p\n" | sort -r | head -10
  
  # via %Td-%Tm-%TY
  $ find ~/.marslo -type f -printf "\n%Td-%Tm-%TY %TT %p" |
    sort -b -k1.7,1.10 -k1.4,1.5 -k1.1,1.2 -r
  

  • via awk+sort

    $ cat a.txt
    ABC,1/02/2022,05:50
    OPQ,18/10/2023,07:50
    HIJ,31/09/2023,08:50
    DEF,1/02/2021,06:00
    
    $ awk -F'[,/]' '{printf "%04d-%02d-%02d\t%s\n", $4,$3,$2, $0}' a | sort -r | cut -f2-
    OPQ,18/10/2023,07:50
    HIJ,31/09/2023,08:50
    ABC,1/02/2022,05:50
    DEF,1/02/2021,06:00
    

find and copy

[!TIP]

• * iMarslo: find by timestamp

$ find . -type f -newermt '2023-10-16 00:00:00' -exec cp -a --parents -t /path/to/target "{}" \+

# or
$ diff=$(( ($(date --date "24-02-29" +%s) - $(date --date "231016" +%s) )/(60*60*24) ))
$ find . -type f -daystart -mtime -$((diff+1)) -exec cp -a --parents -t /path/to/target "{}" \+

download and extract

[!TIP|label:references:]

• * see also: iMarslo: download and extract

• gz

  $ wget -O - http://example.com/a.gz    | tar xz
  # or
  $ curl -fsSL http://example.com/a.gz   | tar xz
  # or
  $ curl -fsSL "http://example.com/a.gz" | tar zxvf -
  
  # or: https://www.commandlinefu.com/commands/view/353/extract-tarball-from-internet-without-local-saving
  $ wget -qO - "http://www.tarball.com/tarball.gz" | tar zxvf -
  

• tar.gz

  $ curl -fsSL https://dlcdn.apache.org/maven/maven-3/3.9.5/binaries/apache-maven-3.9.5-bin.tar.gz | tar xzf - -C /path/to/targeT
  

• tar.xz

  $ curl -fsSL https://ftp.gnu.org/gnu/glibc/glibc-2.38.tar.xz | tar -xJf - -C /path/to/target
  

• zip

  $ curl -fsSL https://downloads.gradle.org/distributions/gradle-8.4-bin.zip | bsdtar xzf - -C /path/to/target
  
  # with password
  $ curl -fsSL https://path/to/file.zip | bsdtar -xzf- --passphrase <PASSWD_OF_ZIP> - -C <EXTRACT_PATH>
  

mirror website

$ wget --mirror --page-requisites --html-extension --convert-links $URL

# https://www.linuxjournal.com/content/downloading-entire-web-site-wget
$ wget --recursive --no-clobber --page-requisites --html-extension --convert-links --restrict-file-names=windows --domains website.org --no-parent sample.com

# or download entire website: https://www.commandlinefu.com/commands/view/901/download-an-entire-website
$ wget --random-wait -r -p -e robots=off -U mozilla http://www.example.com

# https://superuser.com/a/1415765/112396
$ wget --recursive --level 5 --no-clobber --page-requisites --adjust-extension --span-hosts --convert-links --restrict-file-names=windows --domains sample.com --no-parent sample.com

# https://www.commandlinefu.com/commands/view/30/retrieve-a-list-of-all-webpages-on-a-site
$ URL=www.example.com && wget -rq --spider --force-html "http://$URL" && find $URL -type d > url-list.txt && rm -rf $URL

• download image only

  $ wget -r -l1 --no-parent -nH -nd -P/tmp -A".gif,.jpg" http://example.com/images
  

kubectl apply from stdin

$ cat << EOF | kubectl create -f -
apiVersion: v1
kind: Secret
metadata:
  name: mysecret
type: Opaque
data:
  username: $(echo -n 'admin' | base64)
  password: $(echo -n 'password' | base64)
EOF

show 256 colors

$ for code in {0..255}; do echo -e "\e[38;05;${code}m $code: Test"; done)

# or: https://www.commandlinefu.com/commands/view/6138/show-numerical-values-for-each-of-the-256-colors-in-bash
$ for i in {0..255}; do echo -e "\e[38;05;${i}m${i}"; done | column -c 80 -s ' '; echo -e "\e[m"

# or: https://www.commandlinefu.com/commands/view/11759/show-numerical-values-for-each-of-the-256-colors-in-bash-for-bold-and-normal-fonts
$ for code in $(seq -w 0 255); do for attr in 0 1; do printf "%s-%03s %bTest%b\n" "${attr}" "${code}" "\e[${attr};38;05;${code}m" "\e[m"; done; done | column -c $((COLUMNS*2))
# better vesion
$ for code in $(seq -w 0 255); do for attr in 0 1; do printf "%b%s-%03s%b\n"  "\e[${attr};38;05;${code}m" "${attr}" "${code}" "\e[m"; done; done | column -c $((COLUMNS*3))

# .. zsh ..
# or: https://www.commandlinefu.com/commands/view/5876/show-numerical-values-for-each-of-the-256-colors-in-zsh
$ for code in {000..255}; do print -P -- "$code: %F{$code}Test%f"; done

# or: https://www.commandlinefu.com/commands/view/12471/show-numerical-values-for-each-of-the-256-colors-in-zsh
for i in {0..255}; do echo -e "\e[38;05;${i}m\\\e[38;05;${i}m"; done | column -c 80 -s ' '; echo -e "\e[m"

rm and exclude

$ rm !(*.foo|*.bar|*.baz)

# https://www.commandlinefu.com/commands/view/4576/remove-everything-except-that-file
$ find . ! -name <FILENAME> -delete

# https://www.commandlinefu.com/commands/view/4570/remove-everything-except-that-file
$ ( shopt -s extglob; rm !(<PATTERN>) )

split file to equal size

$ split -b4m file.tgz file.tgz. ; for i in file.tgz.*; do SUBJ="Backup Archive"; MSG="Archive File Attached"; echo $MSG | mutt -a $i -s $SUBJ YourEmail@(E)mail.com

sync mirror

[!NOTE]

• How to create public mirrors for CentOS
• Configure DNF/Yum Mirror Server

$ rsync -aqzH --delay-updates --delete-after  msync.centos.org::CentOS /path/to/local/mirror/root

# stream 9
$ rsync -aqzH --delay-updates --delete-after rsync.stream.centos.org::CentOS-Stream-All /path/to/local/mirror/root

# or src
$ rsync -aqzH --delay-updates --delete-after rsync.stream.centos.org::CentOS-Stream-nosrc /path/to/local/mirror/root

# exclude debuginfo
$ rsync -aqzH --delay-updates --delete-after rsync.stream.centos.org::CentOS-Stream-nodebug /path/to/local/mirror/root

get all declare

[!NOTE|label:references:]

• How to list all variables names and their current values?
• What is the difference between source and export?

$ declare
$ declare -p
$ declare -xp

# or
$ typeset
$ typeset -p

# or
$ compgen -v
$ compgen -v | while read line; do echo $line=${!line};done
$ compgen -v | while read line; do declare -p $line; done

# or
$ export
$ printenv

print env

[!NOTE|label:references:]

• List all shell variables

$ set -o posix ; set | awk -F '=' '{ print $1 }'

# or
$ env
$ env | awk -F '=' '{ print $1 }'
$ env | awk -F '=' '{ print $1 }' | tr '\n' ' '

# or
$ printenv

using string as variable name

[!NOTE|label:references:]

• 3.5.3 Shell Parameter Expansion
• How to get a variable value if variable name is stored as string?
• Dynamic variable names in Bash

• eval

  $ aa='echo me'
  $ var='aa'
  $ eval echo \$$var
  echo me
  

• ${!var}

  $ var1="this is the real value"
  $ a="var1"
  $ echo "${!a}"
  this is the real value
  

• more usage

  $ sunny='''
  \033[38;5;226m    \\   /    \033[0m
  \033[38;5;226m     .-.     \033[0m
  \033[38;5;226m  ― (   ) ―  \033[0m
  \033[38;5;226m     `-’     \033[0m
  \033[38;5;226m    /   \\    \033[0m
  '''
  
  $ fewClouds='''
  \033[38;5;226m   \\  /\033[0m
  \033[38;5;226m _ /\"\"\033[38;5;250m.-.    \033[0m
  \033[38;5;226m   \\_\033[38;5;250m(   ).  \033[0m
  \033[38;5;226m   /\033[38;5;250m(___(__) \033[0m
  
  '''
  
  $ codeMap=(
               ["01"]="sunny"
               ["02"]="fewClouds"
             )
  $ icon="$(/usr/bin/curl -sg "https://api.openweathermap.org/data/3.0/onecall?lat=37.3541132&lon=-121.955174&units=metric&exclude=hourly,daily,minutely,alerts&appid=${OWM_API_TOKEN}" | jq -r .current.weather[].icon)"
  $ echo ${icon}
  02n
  
  $ echo -e "${!codeMap["${icon:0:-1}"]}"
  

  

<<<, < <(..)

[!TIP]

• < <( is Process Substitution
  • The difference between <(...) and >(...) is merely which way the redirections are done

< <(..) && > >(..)

[!NOTE]

• process substitution

• syntax

  $ command1 < <( command2 )
  # equals to
  $ command2 | command1
  
  # if read from file, then using `< /path/to/file`
  

• SubShell

• example:

  $ while read line; do echo "-- ${line} --"; done < <(ls -1)
  
  # equals to: http://mywiki.wooledge.org/BashFAQ/024
  $ ls -1 | while read line; do echo "-- ${line} --"; done
  # equals to
  $ ls -1 | xargs -n1 -i bash -c "echo \"-- {} --\""
  
  # equals to read from file via `< /path/to/file`
  $ ls -1 > ls.txt
  $ while read line; do echo "-- ${line} --"; done < ls.txt
  

$ wc < <(date)
    1       6      29

# same as:
$ date | wc
    1       6      29

• < <(..)

  [!TIP|label:referencs:]

  • subshell

  • tips:

    # If commandA can read the data from stdin
    commandB | commandA                 # You can now get the exit code of commandB from PIPESTATUS.
    commandB > >(commandA)              # You can now get the exit code of commandB from $? (or by putting this in an if)
    
    # If commandA cannot read it from stdin, but requires a file argument
    commandB > >(commandA <(cat))       # Again, commandB's exit code is available from $?
    
    # You can also keep commandB's output in memory.  When you do this, you can get commandB's exit code from $? or put the assignment in an if
    b=$(commandB); commandA <<< "$b"    # Here, commandA reads commandB's output from stdin
    

  • common usage

    $ diff <(sort list1) <(sort list2)
    
    # or
    $ while read file; do
        echo -e "\n\033[1;33m${file}\n---\033[0m"
        sed -n "/<<<<<<< HEAD/,/>>>>>>> /!d;=;p" ${file}
        echo -e "\n\033[1;33m---\033[0m"
      done < <(git grep --no-color -l "<<<<<<< HEAD")
    

• > >(..)

  [!TIP]

  • Process Substitution
    • >(...) is used less frequently; the most common situation is in conjunction with tee(1).
    • >(...) is handy when redirecting the output to multiple files, based on some criteria.

  # For example:
  $ some_command | tee >(grep A > A.out) >(grep B > B.out) >(grep C > C.out) > /dev/null
  

parameter substitution

arguments substitution

           p1 p2 p3 p4 p5 p6 

 ./args.sh p1 p2 p3 p4 p5 p6 

           p1 p2 p3 p4 p5 p6 

              p2 p3 p4 p5 p6 

              p2             

              p2 p3          

                       p5 p6 

                       p5    

                          p6 

           p1 p2 p3 p4 p5    

• sample with uncertain parameters

  local opt=''
  local loop=true
  local path params
  
  while ${loop} && [[ $# -gt 0 ]]; do
    case "$1" in
      -*) opt+="$1 "; shift;;
       *) loop=false       ;;
    esac
  done
  
  if [[ 1 = "$#" ]]; then
    path=''
    params="$1"
  else
    path=${*: -1}
    params=${*:1:$#-1}
  fi
  

  sample script c.sh

  echo '---------------- before shift -------------------'
  echo ".. \$# : $#"
  echo ".. \$@ : $@"
  echo ".. \$* : $*"
  
  echo '---------------- after shift -------------------'
  opt=''
  ss=''
  loop=true
  
  while $loop && [[ $# -gt 0 ]]; do
    case "$1" in
      -*) opt+="$1 "; shift;;
       *) loop=false       ;;
    esac
  done
  
  echo ".. \$#   : $#"
  echo ".. \$@   : $@"
  echo ".. \$*   : $*"
  echo ".. \$opt : $opt"
  
  if [[ 0 = "$#" ]]; then
    echo -e "\033[0;33mERROR: must provide at least one non-opt param\033[0m"
    exit 2
  elif [[ 1 = "$#" ]]; then
    path=''
    params="$1"
  else
    path=${*: -1}
    params=${*:1:$#-1}
  fi
  
  echo '---------------- result -------------------'
  echo ">> opt    : ${opt}"
  echo ">> params : ${params}"
  echo ">> path   : ${path}"
  

  result

  $ ./c.sh -1 -2 --3-4 a b c d e
  ---------------- before shift -------------------
  .. $# : 8
  .. $@ : -1 -2 --3-4 a b c d e
  .. $* : -1 -2 --3-4 a b c d e
  ---------------- after shift -------------------
  .. $#   : 5
  .. $@   : a b c d e
  .. $*   : a b c d e
  .. $opt : -1 -2 --3-4
  .. $ss  : a b c d e
  ---------------- result -------------------
  >> opt    : -1 -2 --3-4
  >> params : a b c d
  >> path   : e
  
  $ ./c.sh aa bb
  ---------------- before shift -------------------
  .. $# : 2
  .. $@ : aa bb
  .. $* : aa bb
  ---------------- after shift -------------------
  .. $#   : 2
  .. $@   : aa bb
  .. $*   : aa bb
  .. $opt :
  .. $ss  : aa bb
  ---------------- result -------------------
  >> opt    :
  >> params : aa
  >> path   : bb
  
  $ ./c.sh -1
  ---------------- before shift -------------------
  .. $# : 1
  .. $@ : -1
  .. $* : -1
  ---------------- after shift -------------------
  .. $#   : 0
  .. $@   :
  .. $*   :
  .. $opt : -1
  ERROR: must provide at least one non-opt param
  

quotas

• ${@@Q}

  # a.sh
  line="${@@Q}"
  echo $line
  
  $ bash a.sh -a -b --c='1 2 3'
  '-a' '-b' '--c=1 2 3'
  

  # https://stackoverflow.com/a/39463371/2940319
  $ expand-q() { for i; do echo ${i@Q}; done; }
  $ expand-q -a -b --c='1 2 3'
  '-a'
  '-b'
  '--c=1 2 3'
  

  # https://stackoverflow.com/a/72745869/2940319
  function quote() {
    local QUOTED_ARRAY=()
    for ARGUMENT; do
      case ${ARGUMENT} in
        --*=*)
          QUOTED_ARRAY+=( "${ARGUMENT%%=*}=$(printf "%q" "${ARGUMENT#*=}")" )
          shift
        ;;
        *)
          QUOTED_ARRAY+=( "$(printf " %q" "${ARGUMENT}")" )
        ;;
      esac
    done
    echo ${QUOTED_ARRAY[@]}
  }
  
  ARGUMENTS="$(quote "${@}")"
  echo "${ARGUMENTS}"
  

• printf " %q" "${@}"

  [!NOTE]

  • git-effort

  while test -n "$1"; do
    case "$1" in
      -- ) shift; GIT_OPT=$(printf " %q" "${@}"); break ;;
    esac
  done
  GIT_OPT="${GIT_OPT#\ \'\'}"
  

  # https://stackoverflow.com/a/39463371/2940319
  $ params-q() { printf "%q\n" "$@"; }
  $ params-q -a -b --c='1 2 3'
  -a
  -b
  --c=1\ 2\ 3
  

• String replacement

  [!TIP]

  • * iMarslo: add ' or " to strings

  # a.sh
  while test -n "$1"; do
    case "$1" in
      -- ) shift; GIT_OPT="$@";;
      *  ) shift;;
    esac
  done
  
  GIT_OPT=$(echo "${GIT_OPT}" |
               sed -r 's/\s+--/\n--/g' |
               sed -r "s/^([^=]+)=(.+)$/\1='\2'/g" |
               sed -e 'N;s/\n/ /'
            )
  echo $GIT_OPT
  
  $ bash a.sh -a -b -- --c='1 2 3'
  --c='1 2 3'
  

  # https://stackoverflow.com/a/8723305/2940319
  # a.sh
  C=''
  for i in "$@"; do
      i="${i//\\/\\\\}"
      C="$C \"${i//\"/\\\"}\""
  done
  echo $C
  
  $ bash ~/a.sh -a -b --c='1 2 3'
  "-a" "-b" "--c=1 2 3"
  

string manipulations

compound comparison

SC2155

• problematic code:

  ([ "$x" ] || [ "$y" ]) && [ "$z" ]
  

• correct code:

  { [ "$x" ] || [ "$y" ]; } && [ "$z" ]
  

• example
  • git-retag

SC2155

• problematic code:

  export foo="$(mycmd)"
  

• correct code:

  foo="$(mycmd)"
  export foo
  

escape code

[!TIP] references:

• Color Codes, Escapes & Languages
• Escape codes
• Escape sequences
• Quote and Quote-like Operators

echo

echo var name from variable

[!NOTE]

• Chapter 28. Indirect References
• 3.5.3 Shell Parameter Expansion: {!parameter}
• 9.2. Typing variables: declare or typeset
• sample:

  $ foo=bar             # `bar` is the var name
  $ bar=baz             # `baz` is the var value
  

• typeset

  $ typeset -p "${foo}"$
  declare -- bar="baz"
  

• eval \$$

  $ eval echo \$$foo
  baz
  

  • more:

    $ echo \$$foo
    $bar
    # or
    $ echo '$'$foo
    $bar
    

• {!parameter}

  $ echo "${!foo}"
  baz
  

echo var name

[!NOTE]

• Shell: print both variable name and value?
• * How to Echo the Variable Name Instead of Variable Value
• typeset -p
• sample

  $ a1='a'
  $ a2='aa'
  $ c1='c'
  $ c2='cc'
  

• typeset

  $ typeset -p c2
  declare -- c2="cc"
  

• {!parameter@}

  $ echo "${!c@}"
  c1 c2
  
  $ echo "${!a@}"
  a1 a2
  

• more

  superEcho() {
    echo "$1 = ${!1}"
  }
  
  $ superEcho foo
  foo = bar
  $ superEcho bar
  bar = baz
  

ls

[!NOTE|label:references]

• How can I make ls only display files?

# show file only
$ ls -p | command grep -v /

# show folder only
$ ls -p | command grep / | command grep "^."

# show all files ( including hidden )
$ ls -Ap | command grep -v / | command grep "^."

# show all folders ( including hidden )
$ ls -Ap | command grep / | command grep "^."

# show hidden folder only
$ ls -Ap | command grep / | command grep "^\." | command grep "\."

# show hidden file only
$ ls -Ap | command grep -v / | command grep "^\." | command grep "\."

# show all including hidden
$ ls -Ap

# show hidden file and folder
$ ls -Ap | command grep "^\."

bash completion

[!NOTE|label:references]

• * Creating a bash completion script
• * An introduction to bash completion: part 1
• * An introduction to bash completion: part 2

  $ complete -W "--help --verbose --version" foo
  $ foo --<TAB>
  --help
  --verbose
  --version
  

• 8.7 Programmable Completion Builtins
• 8.6 Programmable Completion
• 8.8 A Programmable Completion Example
• cykerway/complete-alias
• Multi Level Bash Completion
• List all commands that a shell knows
• * iMarslo : _vim()
• Integralist/1. bash autocomplete for your custom programs.md
• 8.6 Programmable Completion : _completion_loader()

• 8.4.6 Letting Readline Type For You

• paths:

  • osx: $(brew --prefix)/etc/bash_completion.d
    • completion files in bash-completion@2: $(brew --prefix bash-completion@2)/share/bash-completion/completions/
  • centos: /usr/share/bash-completion/completions or /etc/bash_completion.d
  • ubuntu: /usr/share/bash-completion/completions

• print existing completion

  $ complete -p vim
  complete -o bashdefault -o default -F _fzf_opts_completion vim
  
  $ complete -p ffs
  complete -o bashdefault -o default -o nosort -F _fd ffs
  
  $ complete -p ff
  complete -o bashdefault -o default -o nosort -F _fd ff
  

• remove completion

  $ complete -p vim
  complete -o bashdefault -o default -F _fzf_opts_completion vim
  
  $ complete -r vim
  
  $ complete -p vim
  -bash: complete: vim: no completion specification
  

• list all completions

  $ complete
  
  # show all commands
  $ compgen -c
  

  • more

    # aliases
    $ compgen -a
    
    # built-ins
    $ compgen -b
    
    # keywords
    $ compgen -k
    
    # functions
    $ compgen -A function
    
    # list all the above
    $ compgen -A function -abck
    

  details...

  $ complete
  complete -o default -F _quotaon quotaon
  complete -o default -F _fzf_path_completion mv
  complete -F _postcat postcat
  complete -o default -o nospace -v -F _fzf_var_completion printenv
  complete -o default -F __start_kubectl kcn
  complete -F _filedir_xspec mpg321
  complete -F _filedir_xspec tex
  complete -F _make gmake
  complete -o bashdefault -o default -F _fzf_path_completion diff3
  complete -o default -F _ansible ansible
  complete -o default -F _fzf_path_completion head
  complete -o default -F __start_kubectl kt1
  complete -o default -F __start_kubectl kt2
  complete -o default -F _fzf_path_completion uniq
  complete -F _command else
  complete -o default -F __start_kubectl kt3
  complete -F _ldapdelete ldapdelete
  complete -F _configure configure
  complete -F _filedir_xspec freeamp
  complete -F _lzma lzma
  complete -o default -F __start_kubectl kcc
  complete -F _filedir_xspec gqmpeg
  complete -F _filedir_xspec texi2html
  complete -o default -F _complete_groovydoc groovydoc
  complete -F _filedir_xspec hbpp
  complete -F _xsltproc xsltproc
  complete -F _filedir_xspec jadetex
  complete -F _docker droot
  complete -o default -F _longopt mkfifo
  complete -o bashdefault -o default -F _fzf_path_completion svn
  complete -o default -F _fzf_path_completion tee
  complete -F _javaws javaws
  complete -F _mktemp mktemp
  complete -F _filedir_xspec rpm2cpio
  complete -F _docker dvi
  complete -F _make pmake
  complete -o default -F _repquota repquota
  complete -F _filedir_xspec hbrun
  complete -F _autoscan autoscan
  complete -o default -F __start_kubectl kubectl
  complete -o default -F _screen screen
  complete -F _filedir_xspec ps2pdf14
  complete -o default -F _fzf_path_completion grep
  complete -F _fzf_path_completion vi
  complete -F _autoreconf autoheader
  complete -F _composite composite
  complete -F _fzf_path_completion bat
  complete -F _filedir_xspec ps2pdf13
  complete -o default -F _longopt objdump
  complete -F _filedir_xspec ps2pdf12
  complete -o default -F _longopt sha1sum
  complete -o default -F _longopt cut
  complete -F _filedir_xspec lyx
  complete -o bashdefault -o default -F _fzf_path_completion file
  complete -F _gcc gpc
  complete -F _filedir_xspec latex
  complete -o default -F _look look
  complete -F _gradle gradlew.bat
  complete -o bashdefault -o default -F _fzf_path_completion hx
  complete -F _filedir_xspec poedit
  complete -F _fzf_path_completion view
  complete -o bashdefault -o default -F _fzf_path_completion dirname
  complete -F _function typeset
  complete -o bashdefault -o default -F _fzf_path_completion hg
  complete -F _command nohup
  complete -a -F _fzf_alias_completion unalias
  complete -F _vipw vipw
  complete -g groupdel
  complete -F _make gnumake
  complete -u groups
  complete -F _filedir_xspec chromium-browser
  complete -F _filedir_xspec opera
  complete -F _filedir_xspec kbabel
  complete -F _fzf_host_completion telnet
  complete -F _gcc g77
  complete -F _filedir_xspec bzme
  complete -o bashdefault -o default -F _fzf_complete_ssh ssh
  complete -F _command vsound
  complete -c which
  complete -F _fzf_path_completion tar
  complete -o default -F _longopt m4
  complete -F _filedir_xspec madplay
  complete -o default -F _fzf_opts_completion fzf-tmux
  complete -F _docker drm
  complete -F _filedir_xspec dviselect
  complete -o default -F _fzf_path_completion cp
  complete -F _mas mas
  complete -F _animate animate
  complete -F _man whatis
  complete -o default -F _complete_groovysh groovysh.sh
  complete -F _filedir_xspec evince
  complete -o bashdefault -o default -F _brew brew
  complete -F _docker dcleanall
  complete -F _filedir_xspec realplay
  complete -o default -F _longopt strip
  complete -o bashdefault -o default -o nospace -F __git_wrap__gitk_main gitk
  complete -v readonly
  complete -o nospace -F _fzf_path_completion rsync
  complete -F _ctest ctest
  complete -o nospace -F _fzf_dir_completion cd
  complete -o default -F _complete_groovydoc groovydoc.bash
  complete -F _known_hosts showmount
  complete -F _filedir_xspec kdvi
  complete -o default -F _longopt tac
  complete -F _ldapaddmodify ldapmodify
  complete -F _filedir_xspec elinks
  complete -F _known_hosts fping
  complete -o default -F _longopt env
  complete -o default -F _quota quota
  complete -F _gradle ./gradlew
  complete -u chfn
  complete -F _docker drp
  complete -F _filedir_xspec compress
  complete -F _filedir_xspec pdfjadetex
  complete -F _filedir_xspec kghostview
  complete -F _man man
  complete -F _filedir_xspec pbunzip2
  complete -o default -F _brctl brctl
  complete -c type
  complete -F _ldapcompare ldapcompare
  complete -F _known_hosts ssh-installkeys
  complete -F _filedir_xspec iceweasel
  complete -F _filedir_xspec gtranslator
  complete -F _fzf_path_completion unzip
  complete -o default -F _longopt expand
  complete -o default -F _complete_groovyConsole groovyConsole.bash
  complete -o bashdefault -o default -o nospace -F _fzf_path_completion git
  complete -F _filedir_xspec lrunzip
  complete -o default -F _fzf_path_completion ln
  complete -F _command aoss
  complete -F _docker drps
  complete -F _filedir_xspec ggv
  complete -F _filedir_xspec oomath
  complete -F _filedir_xspec dvipdfmx
  complete -o default -F _fzf_path_completion ld
  complete -F _fzf_path_completion gunzip
  complete -F _filedir_xspec makeinfo
  complete -F _filedir_xspec okular
  complete -o default -F _complete_groovysh groovysh
  complete -F _ldapsearch ldapsearch
  complete -F _command xargs
  complete -j -P '"%' -S '"' jobs
  complete -o default -F _complete_groovy groovy.sh
  complete -F _filedir_xspec oowriter
  complete -o bashdefault -o default -F _fzf_path_completion emacsclient
  complete -F _cpack cpack
  complete -o default -F _fzf_path_completion tail
  complete -o default -F _longopt unexpand
  complete -o default -F _longopt netstat
  complete -F _docker dexe
  complete -o default -F _fzf_path_completion ls
  complete -F _filedir_xspec epiphany
  complete -o nospace -F __gio gio
  complete -o bashdefault -o default -F _fzf_path_completion nvim
  complete -o dirnames -o nospace -F _fzf_dir_completion pushd
  complete -F _filedir_xspec acroread
  complete -o default -o nospace -v -F _fzf_var_completion unset
  complete -F _postmap postalias
  complete -F _nmap nmap
  complete -o default -F _longopt csplit
  complete -F _known_hosts rsh
  complete -F _filedir_xspec sxemacs
  complete -F _command exec
  complete -F _filedir_xspec aviplay
  complete -F _ldapmodrdn ldapmodrdn
  complete -F _filedir_xspec rgvim
  complete -F _chsh chsh
  complete -F _autoconf autoconf
  complete -o default -F _longopt nm
  complete -o default -F _longopt nl
  complete -o default -F _complete_grape grape.bash
  complete -o nospace -F _user_at_host ytalk
  complete -F _fzf_proc_completion kill
  complete -F _fzf_path_completion java
  complete -F _cmake cmake
  complete -u sux
  complete -F _cancel cancel
  complete -F _filedir_xspec znew
  complete -o default -F _complete_groovydoc groovydoc.sh
  complete -F _id id
  complete -o default -F _longopt paste
  complete -F _ldapaddmodify ldapadd
  complete -F _docker dip
  complete -o bashdefault -F _perldoc perldoc
  complete -F _filedir_xspec kwrite
  complete -F _root_command really
  complete -o default -F _complete_groovyc groovyc.bash
  complete -o bashdefault -o default -o nospace -F __git_wrap__tig_main tig
  complete -F _filedir_xspec firefox
  complete -o bashdefault -o default -F _fzf_path_completion open
  complete -F _ip ip
  complete -o default -F __start_kubectl klc
  complete -F _docker drit
  complete -F _filedir_xspec dvipdfm
  complete -F _filedir_xspec ly2dvi
  complete -F _filedir_xspec oodraw
  complete -F _docker drun
  complete -F _import import
  complete -o default -F __start_kubectl kcswatch
  complete -F _gzip pigz
  complete -o default -F __start_kubectl kln
  complete -F _autoscan autoupdate
  complete -F _known_hosts dig
  complete -o nospace -F _user_at_host talk
  complete -F _filedir_xspec xemacs
  complete -F _docker dls
  complete -o nospace -F _dd dd
  complete -F _jarsigner jarsigner
  complete -F _filedir_xspec kpdf
  complete -F _man apropos
  complete -o default -F _longopt df
  complete -F _command eval
  complete -F _docker di
  complete -F _postsuper postsuper
  complete -F _postconf postconf
  complete -F _filedir_xspec bibtex
  complete -o default -F _pip_completion pip
  complete -F _docker dclr
  complete -F _postfix postfix
  complete -F _fzf_path_completion chown
  complete -F _filedir_xspec netscape
  complete -o default -F _longopt wget
  complete -F _command do
  complete -F _cargo cargo
  complete -F _gradle gradle
  complete -F _pgrep pgrep
  complete -F _filedir_xspec gview
  complete -F _filedir_xspec lzfgrep
  complete -o bashdefault -o default -o nosort -F _fd ffs
  complete -F _filedir_xspec lzless
  complete -o default -F _fzf_path_completion du
  complete -F _renice renice
  complete -F _lsof lsof
  complete -F _docker dv
  complete -F _known_hosts tracepath
  complete -o default -F __start_kubectl kit
  complete -o default -F _fzf_path_completion wc
  complete -F _fzf_path_completion gzip
  complete -F _newgrp newgrp
  complete -o default -F _ansible-galaxy ansible-galaxy
  complete -F _filedir_xspec cdiff
  complete -F _fzf_path_completion emacs
  complete -F _filedir_xspec zipinfo
  complete -F _docker dcleani
  complete -F _filedir_xspec google-chrome
  complete -F _gcc c++
  complete -F _crontab crontab
  complete -F _filedir_xspec rview
  complete -A shopt shopt
  complete -F _docker dcleanc
  complete -F _root_command sudo
  complete -F _killall pkill
  complete -F _fzf_path_completion javac
  complete -F _fzf_path_completion ftp
  complete -o default -F _longopt uname
  complete -o bashdefault -o default -F _rg rg
  complete -F _known_hosts ping
  complete -F _filedir_xspec wine
  complete -F _filedir_xspec galeon
  complete -F _filedir_xspec pdflatex
  complete -F _docker dex
  complete -F _known_hosts rlogin
  complete -o default -F _fzf_opts_completion fzf
  complete -F _filedir_xspec portecle
  complete -o default -F _longopt sha384sum
  complete -o default -F _fzf_path_completion rm
  complete -F _filedir_xspec modplugplay
  complete -F _ri ri
  complete -o default -F _quotaoff quotaoff
  complete -F _filedir_xspec dillo
  complete -F _filedir_xspec fbxine
  complete -F _filedir_xspec lokalize
  complete -F _root_command gksudo
  complete -F _command nice
  complete -o default -F _longopt tr
  complete -o default -F _npm_completion npm
  complete -F _filedir_xspec oocalc
  complete -o default -F _complete_groovyc groovyc.sh
  complete -F _gradle gradlew
  complete -o default -F _longopt sha256sum
  complete -F _root_command gksu
  complete -F _filedir_xspec qiv
  complete -F _chgrp chgrp
  complete -F _filedir_xspec ps2pdfwr
  complete -o default -F _edquota edquota
  complete -F _filedir_xspec harbour
  complete -o bashdefault -o default -F _fzf_path_completion basename
  complete -o default -F _longopt ptx
  complete -F _filedir_xspec dvitype
  complete -o nospace -F __gsettings gsettings
  complete -F _gradle ./gradlew.bat
  complete -F _known_hosts traceroute
  complete -F _fzf_path_completion bzip2
  complete -j -P '"%' -S '"' fg
  complete -o bashdefault -o default -o nosort -F _fd ff
  complete -F _convert convert
  complete -F _filedir_xspec unpigz
  complete -o default -F _complete_groovy groovy
  complete -o bashdefault -o default -o nosort -F _fd fd
  complete -F _filedir_xspec mozilla
  complete -F _filedir_xspec dvips
  complete -o default -F _longopt who
  complete -F _montage montage
  complete -F _complete compgen
  complete -F _filedir_xspec ps2pdf
  complete -F _filedir_xspec gpdf
  complete -F _complete complete
  complete -F _filedir_xspec texi2dvi
  complete -o dirnames -F _umount umount
  complete -F _function function
  complete -o bashdefault -o default -F _fzf_path_completion mvim
  complete -o default -F _fzf_path_completion less
  complete -o default -F _longopt mknod
  complete -F _command padsp
  complete -F _passwd passwd
  complete -F _filedir_xspec kate
  complete -F _pkg_config pkg-config
  complete -o default -F _longopt bison
  complete -F _filedir_xspec mozilla-firefox
  complete -F _filedir_xspec kid3-qt
  complete -o default -F _longopt od
  complete -F _fzf_path_completion bunzip2
  complete -o default -o dirnames -F _mount mount
  complete -F _function declare
  complete -F _filedir_xspec pdftex
  complete -F _ag ag
  complete -o default -o nospace -F _fzf_var_completion export
  complete -F _vipw vigr
  complete -o default -F _ansible-doc ansible-doc
  complete -F _nslookup nslookup
  complete -F _ssh slogin
  complete -o nospace -F _alias alias
  complete -F _fzf_path_completion gvim
  complete -F _filedir_xspec kaffeine
  complete -F _stream stream
  complete -F _docker drdp
  complete -o default -F _complete_grape grape.sh
  complete -F _filedir_xspec mpg123
  complete -F _fzf_path_completion find
  complete -F _filedir_xspec lzegrep
  complete -o default -F _ansible-pull ansible-pull
  complete -o default -F _longopt split
  complete -o bashdefault -o default -F _fzf_path_completion zip
  complete -F _ssh autossh
  complete -F _filedir_xspec xv
  complete -o default -F _longopt fold
  complete -F _known_hosts mtr
  complete -o bashdefault -o default -F _fzf_path_completion ruby
  complete -o nospace -F _fzf_path_completion scp
  complete -F _known_hosts ping6
  complete -F _filedir_xspec timidity
  complete -F _filedir_xspec xdvi
  complete -F _filedir_xspec xfig
  complete -F _filedir_xspec xpdf
  complete -o default -F _longopt indent
  complete -o bashdefault -o default -F _fzf_path_completion chmod
  complete -o nospace -F _user_at_host finger
  complete -o bashdefault -o default -o nospace -F _python_argcomplete pipx
  complete -F _ktutil ktutil
  complete -F _xz xz
  complete -F _filedir_xspec oobase
  complete -F _docker dpa
  complete -F _fzf_path_completion perl
  complete -F _root_command kdesudo
  complete -F _docker drmi
  complete -F _filedir_xspec ogg123
  complete -F _filedir_xspec lzgrep
  complete -u w
  complete -F _filedir_xspec ee
  complete -F _sh sh
  complete -o default -F __start_kubectl kubecolor
  complete -F _docker dps
  complete -F _filedir_xspec gharbour
  complete -u su
  complete -o default -F _complete_grape grape
  complete -o default -F _longopt irb
  complete -F _known_hosts host
  complete -o default -F __start_kubectl k
  complete -o bashdefault -o default -F _fzf_path_completion ex
  complete -o default -F _complete_groovyConsole groovyConsole
  complete -o nospace -F __gdbus gdbus
  complete -F _sysctl sysctl
  complete -F _sqlite3 sqlite3
  complete -o default -F _iconv iconv
  complete -F _command tsocks
  complete -F _docker d
  complete -F _xmllint xmllint
  complete -o default -F _fzf_path_completion diff
  complete -F _ldapwhoami ldapwhoami
  complete -F _bzip2 pbzip2
  complete -F _postmap postmap
  complete -o bashdefault -o filenames -F _pandoc pandoc
  complete -F _filedir_xspec bzcat
  complete -F _filedir_xspec unlzma
  complete -F _filedir_xspec dragon
  complete -F _xzdec xzdec
  complete -o default -F _longopt shar
  complete -F _filedir_xspec ooimpress
  complete -F _cpio cpio
  complete -F _filedir_xspec xanim
  complete -o default -F _complete_groovysh groovysh.bash
  complete -o default -F _ansible-vault ansible-vault
  complete -j -P '"%' -S '"' disown
  complete -F _filedir_xspec xine
  complete -o default -F _longopt bash
  complete -o default -F _longopt md5sum
  complete -o bashdefault -o default -F _fzf_path_completion source
  complete -F _filedir_xspec amaya
  complete -F _filedir_xspec gv
  complete -F _make make
  complete -o default -F _fzf_path_completion curl
  complete -A stopped -P '"%' -S '"' bg
  complete -o default -F __start_kubectl kubeproxy
  complete -F _filedir_xspec kid3
  complete -o nospace -F __gresource gresource
  complete -F _filedir_xspec lilypond
  complete -o default -F _longopt bc
  complete -F _identify identify
  complete -F _filedir_xspec modplug123
  complete -o default -F __start_kubectl k4
  complete -F _pack200 pack200
  complete -A binding bind
  complete -o default -F _setquota setquota
  complete -b builtin
  complete -F _unpack200 unpack200
  complete -o default -F _quotacheck quotacheck
  complete -F _filedir_xspec pbzcat
  complete -F _known_hosts tracepath6
  complete -o default -F _complete_groovyc groovyc
  complete -o default -F _longopt shasum
  complete -F _command ltrace
  complete -o default -F __start_kubectl k3
  complete -F _fzf_path_completion gcc
  complete -F __app gapplication
  complete -o bashdefault -o default -F _fzf_path_completion xdg-open
  complete -o default -F _ansible-playbook ansible-playbook
  complete -u write
  complete -F _known_hosts traceroute6
  complete -F _fzf_path_completion jar
  complete -o default -F _longopt date
  complete -F _gcc gcj
  complete -F _filedir_xspec rgview
  complete -o default -F _fzf_path_completion cat
  complete -o default -F _fzf_path_completion awk
  complete -o default -F _complete_groovyConsole groovyConsole.sh
  complete -o default -F _longopt sha512sum
  complete -F _filedir_xspec unxz
  complete -o default -F _longopt seq
  complete -o default -F _longopt mkdir
  complete -F _filedir_xspec rvim
  complete -o default -F __start_kubectl krn
  complete -o default -F _longopt sha224sum
  complete -A helptopic help
  complete -F _fzf_path_completion sftp
  complete -A setopt set
  complete -o default -F __start_kubectl krc
  complete -F _compare compare
  complete -F _tmux tmux
  complete -F _ssh_copy_id ssh-copy-id
  complete -o default -F _fzf_path_completion sort
  complete -o default -F _longopt pr
  complete -o default -F _longopt colordiff
  complete -o default -F _fzf_path_completion patch
  complete -F _fzf_path_completion g++
  complete -o bashdefault -o default -F _fzf_path_completion python
  complete -F _conjure conjure
  complete -F _ldappasswd ldappasswd
  complete -F _filedir_xspec playmidi
  complete -o default -F __start_kubectl kcEvicted
  complete -o default -F _openssl openssl
  complete -o default -F _longopt fmt
  complete -o default -F _fzf_path_completion sed
  complete -F _tcpdump tcpdump
  complete -F _javadoc javadoc
  complete -F _filedir_xspec lzcat
  complete -o default -F _longopt gperf
  complete -F _command time
  complete -F _filedir_xspec zcat
  complete -F _mogrify mogrify
  complete -F _display display
  complete -F _root_command fakeroot
  complete -o default -F _complete_groovy groovy.bash
  complete -F _filedir_xspec lynx
  complete -u slay
  complete -F _filedir_xspec uncompress
  complete -F _autoreconf autoreconf
  complete -F _filedir_xspec xzcat
  complete -o default -F _fzf_dir_completion rmdir
  complete -F _filedir_xspec slitex
  complete -o bashdefault -o default -F _fzf_opts_completion vim
  complete -F _filedir_xspec aaxine
  complete -F _filedir_xspec advi
  complete -o bashdefault -o default -F _fzf_path_completion more
  complete -o default -F _longopt units
  complete -F _docker dcleanfull
  complete -o default -F _longopt touch
  complete -F _filedir_xspec lzmore
  complete -F _command then
  complete -F _command command
  complete -F _docker dkill
  complete -o default -F __start_kubectl kd
  complete -F _known_hosts fping6
  complete -u runuser
  complete -F _filedir_xspec dvipdf
  complete -o default -F __start_kubectl kc
  complete -F _gradle gradle.bat
  

osx

[!NOTE]

• Bash Completion
• How to Enable Bash Completion on macOS

$ brew install bash-completion

$ echo "[ -f /usr/local/etc/bash_completion  ] && . /usr/local/etc/bash_completion" >> ~/.bash_profile
$ cat ~/.bash_profile
[ -f /usr/local/etc/bash_completion ] && . /usr/local/etc/bash_completion

• to check link of bash-completion

  $ brew unlink bash-completion --dry-run
  Would remove:
  /usr/local/etc/bash_completion
  /usr/local/etc/bash_completion.d/abook
  /usr/local/etc/bash_completion.d/ant
  ...
  

• add more completion files

  $ fd --gen-completions | sudo tee $(brew --prefix)/etc/bash_completion.d/fd
  

• more

  $ brew search completion
  ==> Formulae
  apm-bash-completion       docker-completion         open-completion           stormssh-completion
  bash-completion ✔         fabric-completion         packer-completion         t-completion
  bash-completion@2         gem-completion            pip-completion            tmuxinator-completion
  boom-completion           gradle-completion ✔       rails-completion          vagrant-completion
  brew-cask-completion ✔    grunt-completion          rake-completion           wp-cli-completion
  bundler-completion        kitchen-completion        ruby-completion           yarn-completion
  cap-completion            launchctl-completion      rustc-completion          zsh-completions
  conda-zsh-completion      maven-completion          sonar-completion
  django-completion         mix-completion            spring-completion
  
  ==> Casks
  compositor
  

linux

• enable

  if ! shopt -oq posix; then
    if [ -f /usr/share/bash-completion/bash_completion ]; then
      . /usr/share/bash-completion/bash_completion
    elif [ -f /etc/bash_completion ]; then
      . /etc/bash_completion
    fi
  fi
  

• add more completion files

  $ fd --gen-completions | sudo tee /usr/share/bash-completion/completions/fd
  

  • centos

    $ fd --gen-completions | sudo tee /etc/bash_completion.d/fd
    

completion for alias

[!TIP|label:rerefences:]

• * iMarslo: complete-alias
• _complete_alias | cykerway/complete-alias
• How to work with complete -F _start_kubectl when alias contains --kubeconfig? | How do I get bash completion for command aliases?

• download/install

  # download bash_completion.sh for kubectl
  $ curl -fsSL https://github.com/cykerway/complete-alias/raw/master/complete_alias -o ~/.bash_completion.sh
  # or rhel/centos
  $ sudo curl -fsSL https://github.com/marslo/dotfiles/raw/main/.marslo/.completion/complete_alias -o /etc/profile.d/complete_alias.sh
  # or osx
  $ sudo curl -fsSL https://github.com/marslo/dotfiles/raw/main/.marslo/.completion/complete_alias -o $(brew --prefix)/etc/bash_completion.d/complete_alias
  
  $ sudo chmod +x !$
  

• setup for specific alias

  $ echo "complete -F _complete_alias <alias>" >> ~/.bash_profile
  

  • example

    # i.e.: for kubec* ( kubectl or kubecolor )
    $ complete -o nosort -o bashdefault -o default -F _complete_alias $(alias | sed -rn 's/^alias ([^=]+)=.+kubec.+$/\1/p' | xargs)
    
    # or
    $ alias k=kubectl
    $ echo "complete -F _complete_alias k" >> ~/.bash_profile
    

troubleshooting

• -bash: _compopt_o_filenames: command not found

• [-bash: [: too many arguments](../../linux/devenv.md#bash--too-many-arguments)

• $ ssh bash_completion: _comp_compgen_known_hosts__impl: -F: an empty filename is specified

  [!NOTE|label:references:]

  • Problem with ssh and bash-completion
  • Autocomplete server names for SSH and SCP
  • compgen -A hostname | __fzf_list_hosts

  • clear completion

    $ complete -r ssh
    

  • or add into /usr/local/etc/bash_completion.d/ssh or $(brew --prefix)/etc/bash_completion.d/ssh

    ssh completion script

    # https://unix.stackexchange.com/a/181603/29178
    _ssh_hosts()
    {
        local cur prev opts
        COMPREPLY=()
        cur="${COMP_WORDS[COMP_CWORD]}"
        prev="${COMP_WORDS[COMP_CWORD-1]}"
        opts=$(command grep '^Host' ~/.ssh/config ~/.ssh/config.d/* 2>/dev/null | command grep -v '[?*]' | cut -d ' ' -f 2-)
    
        COMPREPLY=( $(compgen -W "$opts" -- ${cur}) )
        return 0
    }
    
    _ssh()
    {
        local cur prev configfile
        local -a config
        # configfile="$HOME/.ssh/config"
    
        COMPREPLY=()
        _get_comp_words_by_ref -n : cur prev
        #cur=`_get_cword :`
        #prev=`_get_pword`
    
        _ssh_suboption_check && return 0
    
        case $prev in
            -F|-i|-S)
                _filedir
                return 0
                ;;
            -c)
                _ssh_ciphers
                return 0
                ;;
            -m)
                _ssh_macs
                return 0
                ;;
            -l)
                COMPREPLY=( $( compgen -u -- "$cur" ) )
                return 0
                ;;
            -o)
                _ssh_options
                return 0
                ;;
            -w)
                _available_interfaces
                return 0
                ;;
            -b)
                _ssh_bindaddress
                return 0
                ;;
        esac
    
        if [[ "$cur" == -F* ]]; then
            cur=${cur#-F}
            _filedir
            # Prefix completions with '-F'
            COMPREPLY=( "${COMPREPLY[@]/#/-F}" )
            cur=-F$cur  # Restore cur
        elif [[ "$cur" == -* ]]; then
            COMPREPLY=( $( compgen -W '-1 -2 -4 -6 -A -a -C -f -g -K -k -M \
                -N -n -q -s -T -t -V -v -X -v -Y -y -b -b -c -D -e -F \
                -i -L -l -m -O -o -p -R -S -w' -- "$cur" ) )
        else
            # Search COMP_WORDS for '-F configfile' or '-Fconfigfile' argument
            set -- "${COMP_WORDS[@]}"
            while [ $# -gt 0 ]; do
                if [ "${1:0:2}" = -F ]; then
                    if [ ${#1} -gt 2 ]; then
                        configfile="$(dequote "${1:2}")"
                    else
                        shift
                        [ "$1" ] && configfile="$(dequote "$1")"
                    fi
                    break
                fi
                shift
            done
            # marslo >> disable _known_hosts_real from $configfile
            # marslo >> using self-defined _ssh_hosts function
            # _known_hosts_real -a -F "$configfile" "$cur"
            _ssh_hosts
            if [ $COMP_CWORD -ne 1 ]; then
                _compopt_o_filenames
                COMPREPLY=( "${COMPREPLY[@]}" $( compgen -c -- "$cur" ) )
            fi
        fi
    
        return 0
    }
    shopt -u hostcomplete && complete -F _ssh ssh slogin autossh
    
    $ complete -F _ssh ssh
    

tricky

alias for sudo

[!TIP|label:references:]

• Aliases not available when using sudo
• 6.6 Aliases

alias sudo='sudo '

get md5sum

• get file in tar without exacting

  $ tar -O -xf file.tar.gz file.txt | md5sum
  
  # or
  $ tar xfO file.tar.gz file.txt | md5sum
  

• get file in zip without extracting

  $ unzip -p file.zip file.txt | md5sum
  

env

• HISTTIMEFORMAT

  # https://www.commandlinefu.com/commands/view/3642/save-date-and-time-for-each-command-in-history
  export HISTTIMEFORMAT="%h/%d-%H:%M:%S "
  
  # or: YYYY-MM-DD HH:MM:SS : https://www.commandlinefu.com/commands/view/3646/save-date-and-time-for-each-command-in-history
  $ export HISTTIMEFORMAT='%F %T '
  

• GREP_OPTIONS

  $ GREP_OPTIONS='-D skip --binary-files=without-match --ignore-case'
  

shortcuts

• inserts the results of an autocompletion in the command line

  $ <command> <kbd>esc</kbd> <kbd>*</kbd>
  

  • i.e.: $ echo | -> esc *

man

• linux file system

  $ man hier
  

• show ascii

  $ man ascii
  

• ASCII code of key

  $ showkey -a