Saving `test` results in a variable

[iLL]

Is there any way to save the result of a "test" command in a variable, or would I have to do something like:

bool=`if [ -d . ]; then echo 1; else echo 0; fi;`

[michaelb]

Shell already does it for you.
In Bourne shell the result of the last executed command is saved in variable $?
In C shell it's a built-in variable called status.

Here's the sample script:

#!/bin/sh
[ -d `pwd` ] 
echo $?
# the statement above should print 0, (success status) 
# because your current directory is obviously a directory.

[ -d /dev/nonsence ] 
echo $?
# the statement above will likely to print 1 (failure), 
# it's unlikely that this directory exists

Note that 0 is always a success, but shell may return other failure codes,
so most often you're only interested to see whether you gor 0 or not:

exec some shell command, then test the result:
if [ "$?" -ne 0 ] ; then
... ...

It is a common practice to include $? in double-quotes, as shown above.
Hope it helps.