mjhjmtu

In the following function, I can iterate through an array and, if a match is found, break out of the loop and continue with the rest of the program (as intended).

I'd like, though, for the function to exit the rest of the program if exactly no matches are found. How can I achieve that? (I can't have it exit the first time a match is not found, and placing an exit 1 at the end of the loop doesn't do what I intend).

I'm sure I'm overlooking something obvious, but what?

#!/usr/bin/env bash 

# Array 
MATLAB_VERSION=(
 MATLAB9.4.app
 MATLAB9.3.app
 MATLAB9.2.app
 MATLAB9.1.app
 MATLAB9.0.app
 MATLAB8.6.app
 MATLAB8.5.app
 MATLAB8.3.app 
 MATLAB8.0.app 
 MATLAB7.5.app 
 MATLAB.app 
)

matlab_check() 
 # is MATLAB*.*.app installed in /Applications? 
 # iterate through array & tell me what you find 

 for MATLAB in "$MATLAB_VERSION[@]"; 
 do 
 if [ -d "/Applications/$MATLAB" ]; then 
 printf "%s\n" "FOUND $MATLAB IN /Applications, CONTINUING..."
 break 
 else 
 printf "%s\n" "SEARCHING for $MATLAB in /Applications..." 
 fi 
 done 
 

matlab_check 

You can return from the whole function immediately when you find a match. That way, you can have a "tail part" after the loop, that only runs if no matches were found. Something like this:

#!/usr/bin/env bash 
# You might not care for this declaration of the array contents,
# but it does the same thing, and keeps my example nice and short
MATLAB_VERSION=( MATLAB9.4..0,8.6,5,3,0,7.5,.app )

# RC 0 = found
# RC 1 = not found
matlab_check() 
 for MATLAB in "$MATLAB_VERSION[@]"; do
 if [ -d "/Applications/$MATLAB" ]; then
 echo "Found in $MATLAB"
 return 0
 fi
 done

 return 1


matlab_check
echo rc is $?

And if you didn't want to be outputting details of where found, the if..fi portion could be reduced down to just this. No need to use return 0 because at this point we know that $? must be 0, hence just return with no arguments.

[ -d "/Applications/$MATLAB" ] && return