Bash - Snippets

Scripts
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some Bash snippets

Change Working Directory

Switch the Working Directory to the Base Path where the Scripts remains. Helpfull for Includes, Log Files, Relative Path and so on …

#!/usr/bin/env bash
script_path=$(dirname "$0")
cd "$script_path"

Check Return Code

Run a Command, store the Return Code, and check if it was successfull or failed

#!/usr/bin/env sh

check_ret () {
  if [[ "$ret" == "0" ]]; then
    echo "Command terminated sucessfully"
  else
    echo "Command returned an Error: ${ret}"
  fi
}

which bash > /dev/null 2>&1
ret=$?
check_ret $ret


which BASH > /dev/null 2>&1
ret=$?
check_ret $ret

exit 0

Source or Execute

You can Source a Script or Execute it. On Different Shells and on different Operation Systems.

#!/usr/bin/env bash

# Var
os=$(uname -mrs)

# Helper function
is_sourced() {
if [ -n "$ZSH_VERSION" ]; then 
    mysh="zsh"
    case $ZSH_EVAL_CONTEXT in *:file:*) return 0;; esac
else  # Add additional POSIX-compatible shell names here, if needed.
    mysh="bash"
    case ${0##*/} in dash|-dash|bash|-bash|ksh|-ksh|sh|-sh) return 0;; esac
fi
return 1  # NOT sourced.
}

# Sample call.
echo
is_sourced && sourced=1 || sourced=0

if [[ $sourced == 0 ]]; then
    echo "sourced: 0"
    mysh=$(echo $SHELL |sed 's#/bin/##')
else
    echo "sourced: 1"
fi

echo "shell:   ${mysh}"
echo "\$SHELL:  ${SHELL}"
echo "os:      ${os}"
echo
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sha256: 14702c6f56acf7fb0c71b5e04b7c9de9264ed0dbbef43c34e34ec12fbd6e8baa