Bash running multiple commands, until one fails while capturing last exit code

Question

My question is partially answered here: gitlab ci scripts during which $? is allowed to be non-zero

In principle, I want to achieve the following in bash:

// assume both functions return truthy values and the 2nd doesn't run if 1st fails

$success = test1() && test2();

someOtherStuff();

exit($success);

GitLab CI scripts terminate immediately when any simple command fails (possibly due to set -e, IDK for sure).

The nearest (and taking that link into consideration):

CODE=0
if test1 && test2; then
    CODE=1
fi

someOtherStuff

exit $CODE

Is there any better way? In particular, I'd like to get the real $CODE not a fake one.

BTW, set -e is not particularly good practice -- see BashFAQ #105. — Charles Duffy
– Charles Duffy, Commented Jan 20, 2018 at 23:54
@CharlesDuffy yes, but what I mean is that it is enabled by default in GitLab CI (or something similar with that same behaviour) - it's not my decision. — Christian
– Christian, Commented Jan 20, 2018 at 23:56
Also, all-caps names are used for variables with meaning to the OS or system, whereas names with at least one lower-case character are reserved for application use. You should use such lowercase names in your own code, to avoid conflicting with system-meaningful variables which may be added in the future. See pubs.opengroup.org/onlinepubs/9699919799/basedefs/…, fourth paragraph. — Charles Duffy
– Charles Duffy, Commented Jan 20, 2018 at 23:56
Yeah, bad habit mixing between uppercase vars required by applications (eg; behat's BEHAT_PARAMS etc) and vars for local use. — Christian
– Christian, Commented Jan 21, 2018 at 0:07
BTW, if you choose to, you can turn set -e off by putting set +e in your script. — Charles Duffy
– Charles Duffy, Commented Jan 21, 2018 at 3:17

Charles Duffy · Accepted Answer · 2018-01-21 00:03:12Z

1

As I understand it, you're asking how to run a series of commands until one fails, and store the exit status of the failing command for future reference, in a manner which is robust against side effects of set -e.

Using test1, test2 and test3 as our commands:

#!/usr/bin/env bash

test1() { return 0; }
test2() { return 2; }
test3() { echo "THIS SHOULD NOT BE RUN"; }
someOtherStuff() { echo "This should be run; current value of retval is $retval"; }

retval=0
test1 && test2 && test3 || retval=$?
someOtherStuff ||: "ignoring a failure here"
exit "$retval"

|| retval=$? makes test1 && test2 && test3 a checked expression, thus immune to set -e.

: is a synonym for true, with a history of conventional use as a placeholder.

Running the above, we have the following output:

This should be run; current value of retval is 2

...and the exit status of the script is indeed 2.

edited Jan 21, 2018 at 0:03

answered Jan 20, 2018 at 23:55

Charles Duffy

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1 Comment

Christian Over a year ago

Cool, wouldn't have thought about that last ||... I'd have expected immediate termination.

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