Log exit code of command, similar to time command

cmd && echo "$?" wouldn't work since it would by necessity only print zeroes (the echo would only execute on successful completion of the preceding command).

Here's a short shell function for you:

tellexit () {
    "$@"

    local err="$?"
    printf 'exit code\t%d\n' "$err" >/dev/tty
    return "$err"
}

This prints the exit code of the given command in a similar manner as the time command does.

$ tellexit echo "hello world"
hello world
exit code       0

$ tellexit false
exit code       1

By redirecting the printf to /dev/tty in the function, we may still use tellexit with redirections without getting junk in our standard output or error streams:

$ tellexit bash -c 'echo hello; echo world >&2' >out 2>err
exit code       0
$ cat out
hello
$ cat err
world

By saving the exit code in a variable we are able to return it to the caller:

$ tellexit false || echo 'failed'
exit code       1
failed

---

A fancier version of the same function also prints the signal that killed the command if the exit code is greater than 128 (which means it terminated due to a signal):

tellexit () {
    "$@"

    local err="$?"

    if [ "$err" -gt 128 ]; then
        printf 'exit code\t%d (%s)\n' "$err" "$(kill -l "$err")" >/dev/tty
    else
        printf 'exit code\t%d\n' "$err" >/dev/tty
    fi

    return "$err"
}

Testing:

$ tellexit sh -c 'kill $$'
exit code       143 (TERM)

$ tellexit sh -c 'kill -9 $$'
Killed
exit code       137 (KILL)

(The local thing requires ash/pdksh/bash/zsh, or you can change it to typeset which a few other shells also understand.)

Use a shell wrapper function thingy. Probably with a different name.

$ exito() { "$@"; echo $?; }
$ exito true
0
$ exito false
1
$ exito echo "test test"      
test test
0
$ 

(This of course will corrupt standard output, so either use the tty as shown by @Kusalananda or do not use it outside of interactive contexts.)

Veering off into unportable territory, some shells can report on the status of all the commands in a pipeline, not just the last one, e.g. in ZSH if you want failures reported from an entire pipeline:

% TRAPZERR() { print >/dev/tty $pipestatus }
% perl -e 'exit 42' | perl -e 'exit 99'
42 99
% false | perl -e 'exit 42' | perl -e 'exit 99'
1 42 99
% perl -e 'exit 42' | perl -e 'exit 99' | true
% 

TRAPZERR otherwise does not fire when there is no error (on the "no news is good news" principal).

GNU time has an option for this:

time -f %x sleep 1
0

Passes through the exit code¹, unless killed by a signal²:

$ /usr/bin/time -f %x sleep 1; echo $?
0
0

$ /usr/bin/time -f %x sleep 2x; echo $?
sleep: invalid time interval ‘2x’
Try 'sleep --help' for more information.
1
1

$ /usr/bin/time -f %x sleep 60s; echo $? # Press ^C before a minute elapses
0
2

If you want to know/handle the signal kill situation, pass -v and grep the stderr for the string Command terminated by signal.

---

¹Thanks to Olivier Dulac for noting the exit code passes through.
²Also, thank you Stéphane Chazelas for pointing out kill signal exit code does not pass through.