Shell-script: valores p.def. para variables

It’s possible to assign a default value to a variable in case it isn’t already defined. The syntax is:

FOO=${FOO:=bar}

Example:

$ FOO=${FOO:=bar}
$ echo $FOO
bar

$ BAR=test
$ BAR=${BAR:=foo}
$ echo $BAR
test

JomPeich d'er Bisente