Question

Running the following code:

#!/bin/bash

set -o pipefail
set -o errtrace
set -o nounset
set -o errexit

function err_handler ()
{
    local error_code="$?"
    echo "TRAP!"
    echo "error code: $error_code"
    exit
}
trap err_handler ERR

echo "wrong command in if statement"

if xsxsxsxs 
    then
        echo "if result is true"
    else
        echo "if result is false"
fi

echo -e "\nwrong command directly"
xsxsxsxs 

exit

produces the following output:

wrong command in if statement
trap.sh: line 21: xsxsxsxs: command not found
if result is false

wrong command directly
trap.sh: line 29: xsxsxsxs: command not found
TRAP!
error code: 127

How can I trap the ‘command not found‘ error inside the if statement too?

Answer 1

You can’t trap ERR for the test in the if

From bash man:

The ERR trap is not executed if the failed  command
is  part  of  the  command list immediately following a while or
until keyword, part of the test in an if statement,  part  of  a
command  executed in a && or || list, or if the command's return
value is being inverted via !

But you could change this

if xsxsxsxs 
then ..

to this

xsxsxsxs 
if [[ $? -eq 0 ]]
then ..