$ seq 1 3 1 2 3 $ seq 1 3 | xargs echo 1 2 3 $ Mentally replace seq 1 3 with any command that lists entries one-per-line on standard out. How can I get more-or-less what you'd expect, i.e. the entries on separate lines (echo 1; echo 2; echo 3;)?
Normally xargs will put several arguments on one command line. To limit it to one argument at a time, use the -n option:
$ seq 3 | xargs -n 1 echo 1 2 3 From man xargs:
-n max-args
Use at most max-args arguments per command line. Fewer than max-args arguments will be used if the size (see the -s option) is exceeded, unless the -x option is given, in which case xargs will exit.
-n and -L-L is similar but has an extra feature: unlike -n, lines with trailing blanks are continued onto the next line. Observe:
$ echo $'1 \n2\n3\n4' 1 2 3 4 $ echo $'1 \n2\n3\n4' | xargs -L 1 echo 1 2 3 4 $ echo $'1 \n2\n3\n4' | xargs -n 1 echo 1 2 3 4 
-n and -L differ in terms of use-case? Surely they must differ outside of this trivial example. -L differs in that it has a trailing blank feature. I just added an example illustrating it. (Your answer has my +1) xargs -L? When is the trailing blanks feature useful? A bit more research revealed the answer from Make xargs execute the command once for each line of input:
$ seq 1 3 | xargs -L 1 echo 1 2 3 
xargsnot the command you need. You are using two external commandsseqrespectivelyxargsto achieve something that your shell can do it on it's own. Take for example Brace expansion in bash. You could then issueprintf '%s\n' {1..10}to get the desired resultBrewfilefor homebrew in my own bootstrap script. I'm not sure I can use any features of the shell to do the job.nocommentandonelinecould be combined into one functionnocomment_onelineand putsed '/^#/d;/^.$/d' "$1" | sed -e :a -e '$!N;s/\n/ /;ta'