Shash Shash - 4 months ago 7
Linux Question

Why should there be a space after '[' and before ']' in a Bash script?

I was trying to write a bash script that uses an


if [$CHOICE -eq 1];

The script was giving me errors until I gave a space after
and before
as shown below:

if [ $CHOICE -eq 1 ];

My question here is, why is the space around the square brackets so important in Bash?


Once you grasp that [ is a command, a whole lot becomes clearer!

[ is another way to spell "test".

help [

However while they do exactly the same, test turns out to have a more detailed help page. Check

help test

...for more information.

Furthermore note that I'm using, by intention, help test and not man test. That's because test and [ are shell builtin commands nowadays. Their feature set might differ from /bin/test and /bin/[ from coreutils which are the commands described in the man pages.