CODEWITHSUNDEEP
bash
Vivek Goel
Vivek Goel

Reputation: 24160

Bash ignore error and get return code

I am using set -e to abort on errors.

But for particular one function I want to ignore error and on error I want return code of the function.

Example:

do_work || true 
 if [ $? -ne 0 ] 
  then
   echo "Error"
  fi

But it is not work return code is always true due || true

How to get return code on do_work on error ?

Upvotes: 12

Views: 9228

Answers (5)

Mark
Mark

Reputation: 111

Several of the answers given here are not correct, because they result in a test against a variable that will be un-defined if do_work succeeds.

We need to cover the successful case as well, so the answer is:

set -eu
do_work && status=0 || status=1

The poster's question is a little ambiguous because it says in the text "on error I want return code" but then the code implies "I always want the return code"

To illustrate, here is problematic code:

set -e

do_work() {
    return 0
}

status=123

do_work || status=$?
echo $status

In this code the value printed is 123, and not 0 as we might hope for.

Upvotes: 11

l0b0
l0b0

Reputation: 58948

do_work || status=$?
if [ $status -ne 0 ]
then
    echo "Oh no - Fail whale $status has arrived"
fi

Upvotes: 1

Gordon Davisson
Gordon Davisson

Reputation: 126038

do_work || {
    status=$?
    echo "Error"
}

Upvotes: 12

cdarke
cdarke

Reputation: 44424

One way is to use a pipe, -e only looks at the right-most result of a pipe:

set -e

do_work | true

retn=${PIPESTATUS[0]}
if (( $retn != 0 ))
then   
    echo "Error $retn"
fi     
echo Ending

I wrote a simple do_work which just did exit 42 and got the following output:

Error 42
Ending

The PIPESTATUS array is maintained by Bash, with each element giving the return code of each part of the pipeline. We need to capture it at once (hence $retn) since it is overwritten at each command.

Of course this might be problematic if your do_work includes a pipe itself.

Upvotes: 4

Janito Vaqueiro Ferreira Filho
Janito Vaqueiro Ferreira Filho

Reputation: 5072

You could use a subshell shortcut:

( set +e; do_work )
 if [ $? -ne 0 ]
  then
   echo "Error"
  fi

Hope this helps =)

Upvotes: 8

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