Scripting

Conditionally run application

#!/bin/bash

if ! pidof "TSMApplication.exe" > /dev/null
then
    echo "Stopped"
else
    echo "Running"
fi

Bash

I/O Redirection on tldp.org

https://linuxhint.com/bash_stdin_stderr_stdout/

• stdout (file descriptor = 1)
• stderr (file descriptor = 2)

$ echo "yo" > stdout_replacement.txt

$ sdtbhtb 2> stderr_replacement.txt

$ echo "hello world" 1>output.log 2>debug.log

shopt – Shell Options

https://ss64.com/bash/shopt.html

https://www.gnu.org/software/bash/manual/html_node/The-Set-Builtin.html

shopt -s extglob
rm *.!(txt)

https://unix.stackexchange.com/questions/78376/in-linux-how-to-delete-all-files-except-the-pattern-txt

Variables

move all files except some

mkdir archived
mv !(archived) archived/

Create several folders at once

mkdir /docs/folder{1..5}

Script on one line

tests: https://en.wikipedia.org/wiki/Test_(Unix)

if [ sometest ] ; then instruction1; instruction2; instruction19; fi

if [ ! -e /dir ] ; then mkdir /dir; chown leo /dir; fi

Replacing a pattern in a variable inline

To replace the first occurrence of a pattern with a given string, use ${parameter/pattern/string}

To replace all occurrences, use ${parameter//pattern/string}

Here: replace every occurrence of an empty space with an underscore (useful for those hated M$ paths full of it)

DIRBASENAME=`basename ${directory// /_}`

Curly Braces