Ending the execution

How to exit: exit()

If you are running a script and want to stop execution and return to the shell the right way, you should use the exit() function.

Why?

• with the exit() function you can specify the exit status code. The status 0 means “everything is fine”, the status value greater than 0 means something went wrong with the execution;
• with exit() function it is possible to specify a string as parameter, printed at the end of the execution;
• when the exit() function is called, a callback function is automatically executed. The function executed is defined with register_shutdown_function().

Exit parameter

exit(0); // exit and returns 0 exit code, everything is ok;
exit(1); // exit and returns 1 exit code, something went wrong;
exit("Good bye") // exit, returns 0 and it displays "Good bye"

The exit code is a convention to communicate the exit status of your execution to the shell that started executing the script. For example, in your shell environment you can detect the exit code via $? shell variable.

php -r 'exit(1);'
if [[ $? -ne 0 ]] ; then ; echo "there was an error executing your php script"; fi