Bash conditionals: how to “and” expressions? (if [ ! -z $VAR && -e $VAR ])

Question

I guess I\'m not clear on how to do \"and\" tests. I wanted to make sure an argument existed which was working well with [ -e $VAR ], but it turns out that was also

Answer 1

Simply quote your variable:

[ -e "$VAR" ]

This evaluates to [ -e "" ] if $VAR is empty.

Your version does not work because it evaluates to [ -e ]. Now in this case, bash simply checks if the single argument (-e) is a non-empty string.

From the manpage:

test and [ evaluate conditional expressions using a set of rules based on the number of arguments. ...

1 argument

The expression is true if and only if the argument is not null.

(Also, this solution has the additional benefit of working with filenames containing spaces)