Return value error in bash scripts

Question

I have bash script like this:

rm ~/sqoop/"$TABLE"/*
rmdir ~/sqoop/"$TABLE"
return $?

After execution this script it returns a value to next process but even though the script run successfully and executing all stages in script completed successfully it is returning 1.

Because this - the next process is not taking place.

If I remove the return statement the next process going smoothly. this problem came after the Hadoop cluster up gradation which having Ubuntu 14 and new cluster have Ubuntu 16.

Can you please help us to understand what is issue and how the next process is running successfully if remove the return command here and what is impact in production if remove the Return statement?

Answer 1

The return statement returns an error if the statement is not executed from a function or a dot-script (a sourced script).

In shell functions and dot-scripts, use return. In scripts, use exit.

A short script like

#!/bin/bash

return 0

will produce the error message

line 1: return: can only `return' from a function or sourced script

and it will set $? to 1.

If you don't exit the script with an explicit exit (or if you exit with exit but without specifying a exit code), the return code of the script as a whole will be the same as the last executed command.

Having exit "$?" is the same as plain exit, and if it's at the end of the script, this can be left out completely.

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In general, I also suggest that you use $HOME rather than tilde in scripts. This is because $HOME works like any other variable, whereas tilde is expanded in a separate expansion step, which means that it does not behave as a variable and that it is not expanded in quoted strings. $HOME is also more descriptive and since it's a script, you can spend few extra keystrokes to make the code more readable.