fyi haven't tested it but locally on my Mac I get this error:

 ps --version
ps: illegal option -- -
usage: ps [-AaCcEefhjlMmrSTvwXx] [-O fmt | -o fmt] [-G gid[,gid...]]
          [-g grp[,grp...]] [-u [uid,uid...]]
          [-p pid[,pid...]] [-t tty[,tty...]] [-U user[,user...]]
       ps [-L]

so this doesn't seem to work on mac.

I guess we can just use ps/awk then.

it works for the ps, but does not work for awk on my mac.
probably because the response for awk is:

➜  ~/dev/sites/matomo git:(l3-81-no-which) ✗ awk
usage: awk [-F fs] [-v var=value] [-f progfile | 'prog'] [file ...]

@flamisz what is the return code for awk on mac?

@diosmosis I'm on Debian (so GNU awk) and for me awk also doesn't return 0 (I guess because it doesn't run without an arg)

awk ; echo $?
Usage: awk [POSIX or GNU style options] -f progfile [--] file ...
Usage: awk [POSIX or GNU style options] [--] 'program' file ...
POSIX options:          GNU long options: (standard)
        -f progfile             --file=progfile
        -F fs                   --field-separator=fs
        -v var=val              --assign=var=val
Short options:          GNU long options: (extensions)
        -b                      --characters-as-bytes
        -c                      --traditional
        -C                      --copyright
        -d[file]                --dump-variables[=file]
        -D[file]                --debug[=file]
        -e 'program-text'       --source='program-text'
        -E file                 --exec=file
        -g                      --gen-pot
        -h                      --help
        -i includefile          --include=includefile
        -l library              --load=library
        -L[fatal|invalid|no-ext]        --lint[=fatal|invalid|no-ext]
        -M                      --bignum
        -N                      --use-lc-numeric
        -n                      --non-decimal-data
        -o[file]                --pretty-print[=file]
        -O                      --optimize
        -p[file]                --profile[=file]
        -P                      --posix
        -r                      --re-interval
        -s                      --no-optimize
        -S                      --sandbox
        -t                      --lint-old
        -V                      --version

To report bugs, see node `Bugs' in `gawk.info'
which is section `Reporting Problems and Bugs' in the
printed version.  This same information may be found at
https://www.gnu.org/software/gawk/manual/html_node/Bugs.html.
PLEASE do NOT try to report bugs by posting in comp.lang.awk,
or by using a web forum such as Stack Overflow.

gawk is a pattern scanning and processing language.
By default it reads standard input and writes standard output.

Examples:
        awk '{ sum += $1 }; END { print sum }' file
        awk -F: '{ print $1 }' /etc/passwd
1

So there also doesn't seem to be a POSIX command we could use.
So either we try something like awk 'BEGIN {print "ping"}' or go back to command -v

what about using something like awk -Wversion 2>/dev/null || awk --version ?

@sgiehl's suggestion or a variant of it sounds like the best idea to me. I'll run some tests w/ my macbook

@Findus23 👍 I was specifically thinking of having multiple commands w/ ||.

On Mac it awk returns status code 1. @diosmosis is there an issue for this? It may be acceptable that it won't work for some people where they don't have which and we may need to change nothing since it at least mostly works for most users and may be better to not regress anything?

@tsteur the issue is L3-81

👍 commented there

The command awk --version or awk -V works for GNU Awk, but mawk doesn't support --version or -V
@sgiehl's suggestion to use awk -Wversion 2>/dev/null || awk --version works for both gawk and mawk for me.

The returnsSuccessCode() actually appends a > /dev/null 2>&1; echo $? to the provided command. shouldn't the commands we provide here be wrapped in brackets so the appended > /dev/null 2>&1 does not only apply to the last command?

btw @diosmosis should be fine detecting AWK like this. Be good to check out comment from @sgiehl

Had just another thought before why not put the command we use awk '! /defunct/ {print $1} in a constant and check if we get expected output?

like run echo " 537 s000 Ss 0:00.05 login -pfl theuser /bin/bash -c exec -la bash /bin/bash" | awk '! /defunct/ {print $1}' we expect to get back 537? This way we would know if the command is there and behaves the way we expect maybe? Not 100% sure if it's a good idea but this way might be best to detect if archiving will work. Of course no longer such a good idea if we were to use multiple / different awk commands.

Same could be maybe done for ps instead of checking if command exists we use ps x 2 and we check whether we get a 0 exit code since this is also what the class actually executes. I remember in past there were sometimes issues with the arguments where PS worked but not specific arguments and this way maybe would detect if we get what we expect or so.

Or maybe even easier could we simply execute getListOfRunningProcesses and/or getRunningProcesses and check whether we get a 0 response code (can't check for !empty maybe if no processes are detected). Just a thought to maybe simplify this.

@tsteur @sgiehl updated the check + removed the || use.

btw for consistency can we use shell_exec here as well?