Bash Script Error Catching

Question

I am very new to bash scripts, and for my first script attempt I am submitting files to my professor\'s dropbox within the same server.

The code is this:

Answer 1

Although you can test $?, you can also test the exit status of a command directly:

if cp -rv /path/to/lab$1 /path/to/dropbox
then echo Submission successful
fi
exit $?

The errors were already reported to standard error by cp. The exit shown will exit with status 0 (success) if cp was successful; otherwise, it exits with the status that cp exited with.

Clearly, you can wrap that in a loop if you want to, or you can make it non-interactive (but any exit terminates the script).

Answer 2

To check the return code from the previous command, you can use the $? special variable as follows:

if [ "$?" -ne "0" ]; then
  echo "Submission failed"
  exit 1
fi

echo "Submission successful."

Additionally, if you want a clean prompt, you can redired stderr as explained here.

Finally, you can also use this in the script that uses scp, since it works regardless of the command you're using.

Answer 3

echo "Submit lab$1?"

read choice

echo "Send to Prof's dropbox"
cp -rv /path/to/lab$1 /path/to/dropbox &>/dev/null

[ $? -eq 0 ] && { #success, do something } || { #fail, do something }

And so on...