How to exit if a command failed?

Question

I am a noob in shell-scripting. I want to print a message and exit my script if a command fails. I\'ve tried:

my_command && (echo \'my_command failed         


        

Answer 1

I've hacked up the following idiom:

echo "Generating from IDL..."
idlj -fclient -td java/src echo.idl
if [ $? -ne 0 ]; then { echo "Failed, aborting." ; exit 1; } fi

echo "Compiling classes..."
javac *java
if [ $? -ne 0 ]; then { echo "Failed, aborting." ; exit 1; } fi

echo "Done."

Precede each command with an informative echo, and follow each command with that same
if [ $? -ne 0 ];... line. (Of course, you can edit that error message if you want to.)