{{tag>Brouillon Bash Script}}

= Script bash fonctions en vrac

Voir [[notes_hexa|Fonctions conversion Hexa ASCII]]

Fonctions récupérées de http://www.trapkit.de/tools/checksec.sh

<code bash>
#! /bin/bash
 
set -euo pipefail
IFS=$' \t\n'
export LC_ALL=C

SCRIPT_NAME=$(basename "$0")
readonly SCRIPT_NAME
SCRIPT_DIR=$(readlink -m "$(dirname "$0")")
readonly SCRIPT_DIR

# Launch this script as root
if [ $EUID != 0 ]; then
    sudo "$0" "$@"
    exit $?
fi

[ -r /etc/default/plop ] && . /etc/default/plop

# check if command exists
command_exists() { type $1  > /dev/null 2>&1; }

command_exists() {
	command -v "$1" >/dev/null 2>&1 || (
		echo "I require $1 but it's not installed. Aborting." >&2
		exit 127
	)
}

for COMMAND in "nova" "glance" "dmidecode" "tr"
do
  command_exists "${COMMAND}"
done


exit_si_erreur(){
    if [ $1 != 0 ]
    then
        echo "Sortie en erreur."
        exit 1
    fi
}

# plop ; exit_si_erreur $?

get_mountpoint() { df -l --output=target "$1" |sed -e "1d" ;}


# check if directory is empty
dir_is_empty() {
  if [ -z "$(ls -A $1)" ]
  then
    return 0
  else
    return 1
  fi
}

isNonEmptyStr() { echo "$@" | grep -q -v -e "^$" ;}

is_empty_var() {
        local var
        var=$1
        if [ "${!var:-}" == "" ]
        then
                return 0 # TRUE
        else
                return 1 # FALSE
        fi
}

is_valid_value_var() {
  # Syntax exemple :
  # is_valid_value_var BOOL y n && echo "VAR 'BOOL' is 'y' or 'n'"
  # is_valid_value_var NUM 1 2 3 || echo "VAR 'NUM' is not 1, 2, or 3"
  local var=$1
  shift
  for value in "$@"
  do
      if [ "${!var-}" == "$value" ]
      then
          return 0 # TRUE
      fi
  done
  return 1 # FALSE
}




isDevMounted() { findmnt --source "$1" >/dev/null;} #device only
isPathMounted() { findmnt --target "$1" >/dev/null;} #path   only
isMounted() { findmnt          "$1" >/dev/null;} #device or path
is_mount() { findmnt -M "$1" >/dev/null ;}
# Voir aussi la commande "mountpoint"

# check user privileges
root_privs() {
  if [ "$(/usr/bin/id -u)" -eq 0 ]
  then
    return 0
  else
    return 1
  fi
}

# Require that this runs as root.
[ "$UID" -eq 0 ] || exec sudo "$0" "$@"

# check if input is numeric
isNumeric() { echo "$@" | grep -q -v -e "[^0-9]" ; }

# check if input is a string
isString() { echo "$@" | grep -q -v -e "[^A-Za-z]" ; }

# check if file exist
file_exist() {
  if [ $# -ne 1 ]
  then
      echo "illegal number of parameters"
      exit 2
  fi
  [ -e "$1" ]
}

#
return_only_files_exists() { ls -1 "$@" 2>/dev/null ;}


if !(isString "$2")
then
    printf "\033[31mError: Please provide a valid process name.\033[m\n\n"
    exit 1
fi

if ! command -v zgrep &> /dev/null
then
        zgrep() {
                zcat "$2" | grep "$1"
        }
fi

check_device() {
	if [ -c "$1" ]
        then
		wrap_good "$1" 'present'
	else
		wrap_bad "$1" 'missing'
		EXITCODE=1
	fi
}

strip_comment() { grep -Ev -e '^\s+#|^#' - ;}

abs() {
        local -i VAL=$1
        echo "${VAL#-}"
}


calc_sum() { awk '{s+=$1} END {printf "%.0f", s}' "$*" ;}


mk_calc() { awk "BEGIN { print $* }"; }
# ex : mk_calc 7.5/3.2 => 2.34375
# Voir aussi expr : CACHE_USED=$( expr \( $CACHE_USED \* 1024 \) )

# A helper to make sure that Chrome is linked correctly
function installation_status() {
    google-chrome-stable --version > /dev/null 2>&1
    [ $? -eq 0 ]
}


############ Source : https://github.com/danguita/scripts/blob/master/kickstart/kickstart-debian.sh

say() {
  printf "\n[$(date --iso-8601=seconds)] %s\n" "$1"
}

# shellcheck disable=SC2317
confirm() {
  while true; do
    read -r -p "$1 (y/[n]): " answer
    case $answer in
      [Yy]* ) return 0; break;;
      [Nn]* ) return 1; break;;
      "" ) return 1; break;;
      * ) echo "Please answer yes or no.";;
    esac
  done
}

install_package() {
  sudo apt install --no-install-recommends -y "$@"
}

#########

quote () {
    local quoted=${1//\'/\'\\\'\'};
    printf "'%s'" "$quoted"
}


dequote () {
    eval printf %s "$1" 2> /dev/null
}
</code>




''get_dev.sh''
<code bash>
#! /bin/bash

# Respond to the question : if a new file is created, this will be on which block device ?
# Input arg 1 : path (file)
# Outpout     : path (block device)

set -euo pipefail
IFS=$' \t\n'
export LC_ALL=C

NEW_FILE="$1"

# check if directory exists
dir_exists() {
        if [ -d "$1" ]
        then
                return 0
        else
                return 1
        fi
}

get_parent_dir() {
        local CHEMIN="$1"
        while ! "$(dir_exists "$CHEMIN")"
        do
                CHEMIN=$(dirname "$CHEMIN")
        done
        echo "$CHEMIN"
}

get_device() { df -lP "$(get_parent_dir "$NEW_FILE")" |awk 'NR==2{print $1}' }

get_device "$(get_parent_dir "$NEW_FILE")"
</code>

A la place de 
<code bash>
dir_exists /tmp/plop || mkdir -p /tmp/plop
</code>

Il est préférable de faire d'uuliser la commande ''install''
<code bash>
install -d /tmp/plop
</code>

Faire une division
<code bash>
echo $(( 10 / 3 ))
echo $(( VAR / 3 ))
expr 10 / 3

calc() { awk "BEGIN { print ""$*"" }" }

</code>

<code bash>
my_command || { echo 'my_command failed' ; exit 1; }
</code>

Bash Colors \\
source : https://github.com/moby/moby/blob/master/contrib/check-config.sh
<code bash>
color() {
	local codes=()
	if [ "$1" = 'bold' ]; then
		codes=( "${codes[@]}" '1' )
		shift
	fi
	if [ "$#" -gt 0 ]; then
		local code=
		case "$1" in
			# see https://en.wikipedia.org/wiki/ANSI_escape_code#Colors
			black) code=30 ;;
			red) code=31 ;;
			green) code=32 ;;
			yellow) code=33 ;;
			blue) code=34 ;;
			magenta) code=35 ;;
			cyan) code=36 ;;
			white) code=37 ;;
		esac
		if [ "$code" ]; then
			codes=( "${codes[@]}" "$code" )
		fi
	fi
	local IFS=';'
	echo -en '\033['"${codes[*]}"'m'
}

wrap_color() {
	text="$1"
	shift
	color "$@"
	echo -n "$text"
	color reset
	echo
}

wrap_good() { echo "$(wrap_color "$1" white): $(wrap_color "$2" green)" }

wrap_bad() { echo "$(wrap_color "$1" bold): $(wrap_color "$2" bold red)" ; }

wrap_warning() { wrap_color >&2 "$*" red ; }

error() { printf "${red}!!! %s${reset}\\n" "${*}" 1>&2 ; }

failure() {
    local rc=$?
    echo -e "\t[FAILED]"
    return $rc
}

success() {
    echo -e "\t[  OK  ]"
    return 0
}

# Getpass
read -s password
read -s -p "Password: "

get_free_space() {
	local chemin=$1
	local -i free_mb
	free_mb="$(df --output=avail -m "$chemin" | tail -1 | tr -d ' ')"
	echo "$free_mb"
}

check_free_space() {
	# check_free_space /tmp/ 200
	# will exit if /tmp/ less than 200MB
	local chemin=$1
	local -i min_free_mb=$2
	if [[ "$(get_free_space "$chemin")" -lt min_free_mb ]]
	then
	  echo ERROR: No space left on device >&2
	  exit 28
	fi
}
</code>

Appelle d'une fonction bash depuis un autre shell\\
Même UID pour deux utilisateurs différents
<code bash>
cat <<EOF | bash -s --
same_uid_for_Utilisateur_and_utilisateur()
{
    local -i RET=0
    local -i UID_Utilisateur=$(id -u Utilisateur)
    RET=$(( RET + $? ))
    local -i UID_utilisateur=$(id -u utilisateur)
    RET=$(( RET + $? ))
    
    if [[ (RET -eq 0) && (UID_Utilisateur -ne UID_utilisateur) ]]
    then
        echo "usermod -o -u $(id -u utilisateur) -g $(id -g utilisateur) Utilisateur"
        chown -R utilisateur:utilisateur /var/opt/plop
        usermod -o -u $(id -u utilisateur) -g $(id -g utilisateur) Utilisateur
    fi

    exit
}

same_uid_for_Utilisateur_and_utilisateur
EOF
</code>

Variables
<code bash>
SCRIPTPATH=$(dirname "$(realpath "$0")")

</code>


http://linuxfr.org/users/srb/journaux/waitend-executer-une-commande-apres-une-autre-deja-lancee

Si la commande ''waitpid'' n'est pas présente (util-linux-extra)

<code bash>
waitpid()
{
        while ps -p $1 >/dev/null ; 
        do
                sleep 5
        done
        shift
        "$@"
}
</code>

Strip char / trim => utiliser ''xargs'' ex :
<code bash>
load5=$(echo $UPTIME | awk -F, '{print $5}' | xargs)
</code>


== Gestion des logs

<code bash>
#!/bin/bash
NAME=plop
LOG=/var/log/$NAME/$NAME.log
 
exec >>$LOG 2>&1
exec &> >(tee -i /var/log/stackscript.log)

</code>


== Gestion des erreurs

<code bash>
#! /bin/bash

# to combine ''set -e'' (same as: ''set -o errexit'') with an ERR trap
set -eE  # same as: `set -o errexit -o errtrace`

err_report()
{
    echo "Error on line $1"
}

trap 'err_report $LINENO' ERR

echo hello | grep foo  # This is line number 9
</code>

Source : https://unix.stackexchange.com/questions/39623/trap-err-and-echoing-the-error-line


== Exécution à la sortie

<code bash>
trap 'rm -f "$TMP_INV_INI"' EXIT ERR
</code>


== No sigterm terminate

<code bash>
#!/bin/bash
trap '' SIGTERM

</code>


== Utilisation d'aliases dans un script shell

<code bash>
shopt -s expand_aliases
source ~/.bash_aliases
</code>



== Autres

How to make sure only one instance of a bash script runs ?
<code bash>
if [ $(pidof -x $0| wc -w) -gt 2 ]; then
    echo "More than 1"
    exit
fi
</code>


Note : [[https://fr.wikipedia.org/wiki/NOP|NOP]] en bash :
<code bash>
true
</code>


<code bash>
# We use this to print to the terminal when the context
# of STDOUT is something other than the pty.
declare -r TTY="$(tty)"

printf $'%s %s\n' "${method}" "${path}" >${TTY}
printf $'HTTP/1.1 %s %s\r\n' "${status:?}" "${msg:?}" | tee ${TTY}
</code>


== Bash variable Substitution

Supprimer une extention de fichier 
<code ->
$ VAR="plop.txt"
$ echo ${VAR%.txt}
plop
</code> 

<code ->
$ var=sd_feeef_efe_g
$ echo "${var#?*_}"
feeef_efe_g
</code>

<code ->
$ var=toto-tt-ll
$ echo "${var//-/_}"
toto_tt_ll
</code>

<code ->
$ echo "${a/-/_}"
toto_tt-ll
</code>


Case upper lower majuscule minuscule
<code bash>
x="Hello"
echo $x  # HELLO

y=${x,,}
echo $y  # hello

z=${y^^}
echo $z  # HELLO
</code>

Dernier caractère d'une chaine
<code bash>
echo "${str: -1}"

# ou

echo ${str:0-1}
</code>

Renommer en supprimant un prefix 
<code bash>
for fic in *.j2 ; do mv "$fic" "${fic#PREFIX_}" ; done
</code>

-----------

<code bash>
#!/bin/bash
SCRIPT_PATH="$( cd "$( dirname "${BASH_SOURCE[0]}" )" && pwd )"

${SCRIPT_PATH}/sds_run.sh portal
</code>

-----

<code bash>
negate() {
    if [[ $# -eq 0 ]]; then
        echo "ERROR. ENOSYS Function not implemented" >&2
        return 38
    else
        # ! "${@}"
        "${@}" && return 1 || return 0
    fi
}
</code>

<code ->
$ negate true ; echo $?
1

$ negate false ; echo $?
0

$ true | negate ; echo $?
ERROR. ENOSYS Function not implemented
38

$ false | negate ; echo $?
ERROR. ENOSYS Function not implemented
38
</code>

Voir aussi :
* PIPESTATUS
* pipefail