1

I process files found by ls as

ls /folder/ | parallel -j20 ./command {}

but I need to pass the job number as well. I tried

ls /folder/ | parallel -j20 ./command {1} {2} ::: {1..20}
ls /folder/ | parallel -j20 ./command {} {} ::: {1..20}

but it does not work. I also tried {#} for passing the job number.

Googlebot
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    Note that you should never use the output of ls in a script. Using a for loop or find is always the better solution. – mashuptwice Feb 20 '22 at 11:19
  • @mashuptwice may I ask why? – Googlebot Feb 20 '22 at 11:27
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    https://unix.stackexchange.com/questions/128985/why-not-parse-ls-and-what-to-do-instead

    https://mywiki.wooledge.org/ParsingLs

     – mashuptwice Feb 20 '22 at 11:30
  • @mashuptwice oh thanks. I always work with well-formatted directories, and thus, never thought of that. – Googlebot Feb 20 '22 at 11:32
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    Please [edit] your question and show us the commands you are trying to run. Give us a few file names and then what number should be passed an how. Are you trying to launch things like ./command file1.txt 1 and ./command file2.txt 2 etc.? – terdon Feb 20 '22 at 11:57
  • @terdon ./command script is irrelevant here. Consider it as a bash script with echo "$1 $2". Yes, the aim is to run /command file1.txt 1 or /command 1 file1.txt. The order is not important as I can change the arguments inside the script. – Googlebot Feb 20 '22 at 12:55

2 Answers2

2

The {#} replacement string should be exactly what you need here. For example, given

$ ls
 file1  'file2 with spaces'  'file3'$'\n''with'$'\n''newlines'   file4   file5

then

parallel --null echo {#} {} ::: *
1 file1
2 file2 with spaces
3 file3
with
newlines
4 file4
5 file5

or, if you have enough files to exceed the ARG_MAX limit you could use

printf '%s\0' * | parallel --null echo {#} {}
steeldriver
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0

It is unclear to me what you want to do. Maybe one of these?

ls /folder/ | parallel -j20 ./command {1} {2} :::: - ::: {1..20}
ls /folder/ | parallel -j20 ./command {1} {2} :::: - :::+ {1..20}
ls /folder/ | parallel -j20 ./command {1} {#}
ls /folder/ | parallel -j20 ./command {1} {%}
Ole Tange
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