How to Set Default Values for Bash Variables

2024年3月18日 — Learn how to assign a default value to a variable based on its current value in Bash.

2010年1月6日 — You can use something called Bash parameter expansion to accomplish this. To get the assigned value, or default if it's missing: FOO=$VARIABLE ...

2013年1月27日 — The script below shows a use case where if the $HOME is not set, it will default to /home/$USER}. #!/bin/bash unset HOME echo $HOME:-/home/ ...

2010年12月14日 — bash assign default value ... $parameter:=word} Assign Default Values. If parameter is unset or null, the expansion of word is assigned to ...

2023年9月1日 — This syntax allows you to specify a default value for a variable directly within an expression. ... Setting default values for Bash variables is a ...

Setting Default Values Problem Your script may rely on certain environment variables ... Get bash Cookbook now with the O'Reilly learning platform. O'Reilly ...

2024年5月29日 — Set default value of counter variable in bash script · $(($foo:=1}, foo++)) ? – muru · I think what you're after is slicing an array. – ...

2023年4月5日 — Bash scripts can set defaults for environment variables that are optionally supplied at execution time.

2024年4月28日 — You can set a default environment variable in Bash by using the $VARNAME:=default} syntax, where VARNAME is the name of the variable, and ...

2020年6月24日 — Bash doesn't have any special values for True or False , so the only false value is 0. Then, a variable can be set to an empty string or it ...