A bash function can return a value via its exit status after execution. By default, a function returns the exit code from the last executed command inside the function. It will stop the function execution once it is called. You can use the return builtin command to return an arbitrary number instead.
There are many methods to quit the bash script, i.e., quit while writing a bash script, while execution, or at run time. One of the many known methods to exit a bash script while writing is the simple shortcut key, i.e., “Ctrl+X”. While at run time, you can exit the code using “Ctrl+Z”.
exit-Issuing the exit command at the shell prompt will cause the shell to exit. In some cases, if you have jobs running in the background, the shell will remind you that they are running and simply return you to the command prompt. In this case, issuing exit again will terminate those jobs and exit the shell.
Use:
return [n]
From help return
return: return [n]
Return from a shell function. Causes a function or sourced script to exit with the return value specified by N. If N is omitted, the return status is that of the last command executed within the function or script. Exit Status: Returns N, or failure if the shell is not executing a function or script.
Use return
operator:
function FUNCT {
if [ blah is false ]; then
return 1 # or return 0, or even you can omit the argument.
else
keep running the function
fi
}
If you want to return from an outer function with an error without exit
ing you can use this trick:
do-something-complex() {
# Using `return` here would only return from `fail`, not from `do-something-complex`.
# Using `exit` would close the entire shell.
# So we (ab)use a different feature. :)
fail() { : "${__fail_fast:?$1}"; }
nested-func() {
try-this || fail "This didn't work"
try-that || fail "That didn't work"
}
nested-func
}
Trying it out:
$ do-something-complex
try-this: command not found
bash: __fail_fast: This didn't work
This has the added benefit/drawback that you can optionally turn off this feature: __fail_fast=x do-something-complex
.
Note that this causes the outermost function to return 1.
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