On Tue, Jan 31, 2012 at 12:05 AM, Jochen Spieker <m...@well-adjusted.de> wrote: > lina: >> >> well, a question, >> >> $ seq 0 3 | xargs --verbose echo A >> echo A 0 1 2 3 >> A 0 1 2 3 >> >> How can I make the output as: >> >> A0 A1 A2 A3 > > Your problem in this case is that xargs adds whitespace before adding > arguments. What you can do is to modify seq's output before xargs sees > it: > > $ seq 0 3 | sed -e 's/^/A/' > A0 > A1 > A2 > A3 > > Which leads to: > > $ seq 0 3 | sed -e 's/^/A/' | xargs --verbose echo > echo A0 A1 A2 A3 > A0 A1 A2 A3 > >> P.S Very good explaination. > > Thanks! > > BTW: when requesting these things it is often better to ask for the real > thing you want to achieve. Synthetic examples like these most often > don't cover all cases or leave out important information. For example,
Yes. the ultimate goal is: for i in {0..108} do cat A_$i.txt B_$i.txt C_$i.txt -o ABC_$i.txt (output as ABC_$i.txt) done but here I wish to use only 8 processors at most, total is 16. the administrator of the cluster asked me not to use whole, cause someone else needs SMP server. each cat in my situations last 5~10 mins, > if "A0" should actually be a filename, your next question might be how > to get from "A0" to "A0.jpeg": > > $ seq 0 3 | sed -e 's/^/A/' -e 's/$/.jpeg/' > A0.jpeg > A1.jpeg > A2.jpeg > A3.jpeg I used to do it in a very clumsy way like seq 0 3 | sed 's/^.*$/A$/g' | sed 's/^.*$/&.jpeg/g'. Thanks, it's smart. > > The two sed expressions perform search & replace at the beginning (^) > and at the end ($) of the line-. > > J. > -- > My memories gild my life with rare transcendance. > [Agree] [Disagree] > <http://www.slowlydownward.com/NODATA/data_enter2.html> -- To UNSUBSCRIBE, email to debian-user-requ...@lists.debian.org with a subject of "unsubscribe". Trouble? Contact listmas...@lists.debian.org Archive: http://lists.debian.org/CAG9cJm=3ueqzvefrctabwchntkwtj9wyycnaxrbmjvrqtuc...@mail.gmail.com