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I'm really fond of "null coalescing", where you can set a variable to the first "non-null" value in a list of things. Many languages support this, for example:


String myStr = string1 ?? string2 ?? "default";


var myStr = string1 || string2 || "default";

...etc. I'm just curious if this can be done in Bash to set a variable?


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up vote 13 down vote accepted

The POSIX shell (so includes bash) equivalent would be:


See also the:


variant which checks whether the variable is set or not instead of whether it resolves to the empty string or not (which makes a difference in the cases where a variable is set but empty).

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Not directly.

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