bash
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The **__B__ourne __A__gain __Sh__ell** is the default command language / shell in [[Linux]], and I've never bothered to try any other. You type stuff in (or paste it from stackexchange...) and useful stuff happens. | The **__B__ourne __A__gain __Sh__ell** is the default command language / shell in [[Linux]], and I've never bothered to try any other. You type stuff in (or paste it from stackexchange...) and useful stuff happens. | ||
+ | |||
+ | ===== Features ===== | ||
+ | |||
+ | ==== Arguments ==== | ||
+ | |||
+ | You can use [[getopts]] to read arguments attached to the command. You use a '' | ||
+ | |||
+ | In this example you can use '' | ||
+ | |||
+ | <code bash> | ||
+ | while getopts :io flag | ||
+ | do | ||
+ | case $flag in | ||
+ | i) input=${OPTARG} ;; | ||
+ | o) output=${OPTARG} ;; | ||
+ | esac | ||
+ | done | ||
+ | </ | ||
+ | |||
+ | ==== Conditional Constructs ==== | ||
+ | |||
+ | === if === | ||
+ | |||
+ | |||
+ | -n string True if the length of string is non-zero. -a file True if file exists. DPMT USE -a, it's weird | ||
+ | |||
+ | In the documentation of test you will also see a the switch -e. This switch tests the following argument and evaluates to true if that argument is a file or directory that exists. More useful still is the -f switch which evaluates to true if the following argument exists and is a regular file (as opposed to a directory or a block device, or whatever). | ||
+ | |||
+ | === case === | ||
===== Examples ===== | ===== Examples ===== |
bash.txt · Last modified: 2024/01/10 10:59 by rjt