In replacement strings you can use 'skip()' to skip a command:
$ parallel echo {= '$arg[1] % 2 or skip();' =} ::: {1..5}
1
3
5
--filter can be used with a similar effect:
$ parallel --filter '{1} % 2' echo ::: {1..5}
1
3
5
In theory the skipped commands are never run (right now they are run
with 'true' prepended), but when should they show up?
What should -v do? It does this now:
$ parallel -v --filter '{1} % 2' echo ::: {1..5}
echo 1
1
echo 2
echo 3
3
echo 4
echo 5
5
What should --dry-run do? It does this now:
$ parallel --dr --filter '{1} % 2' echo ::: {1..5}
echo 1
echo 2
echo 3
echo 4
echo 5
Should skipped commands go into the joblog? Right now they get exit
value -2 to signify these are skipped.
$ parallel --jl - --filter '{1} % 2' echo ::: {1..5}
Seq Host Starttime JobRuntime Send Receive
Exitval Signal Command
1 : 1625831554.883 0.004 0 2 0
0 echo 1
2 : 1625831554.886 0.005 0 0 -2
0 echo 2
3 : 1625831554.891 0.006 0 2 0
0 echo 3
4 : 1625831554.898 0.005 0 0 -2
0 echo 4
5 : 1625831554.903 0.001 0 2 0
0 echo 5
Is the current behaviour what you expect? If not: How should it change?
/Ole
