function fork () { tf=$(tempfile -d /tmp -p $1.);echo -n "$tf "; $@ &>$tf& }

Easily run a program in the background without losing output

This function runs a program in the background, and logs all output to an automatically created logfile. That way, you can still get at the output without it clogging up your terminal. Tip: Throw fork() and this: for prog in firefox kate konqueror ;do alias $prog="fork $prog";done into your bashrc, so that they'll automatically run out of the way.
Sample Output
$ fork echo hello world
/tmp/echo.A68NMR   [1] 5747
[1]+  Done                    $@ >&$tf
$cat /tmp/echo.A68NMR
hello world

1
2009-03-25 23:33:54

These Might Interest You

  • Sometimes you have a situation where you cannot properly see the ls output when you are using a terminal w/a dark background. Usually bash has ls aliased to use colors, and you can easily get ls to use the default foreground color via simply unaliasing the command.


    1
    unalias ls
    susannakaukinen · 2009-03-10 11:23:31 4
  • This *does not change the video encoding*, so it's fast (almost purely I/O-bound) and results in a file of nearly the same size. However, OSX (and possibly other programs) will more easily play/seek the file when wrapped as MOV. For example, you can QuickLook the resulting file. This basically does the same as the commercial ClipWrap program, except using the free program ffmpeg. Show Sample Output


    0
    ffmpeg -i "input.mts" -vcodec copy -acodec pcm_s16le "output.mov"
    lgarron · 2014-01-24 13:00:07 0
  • How to figure out what a program is doing. -tt detailed timestamps -f also strace any child processes -v be very verbose, even with common structures -o write output to file -s N capture up to N characters of strings, rather than abbreviating with ...


    0
    strace -ttvfo /tmp/logfile -s 1024 program
    ryanchapman · 2013-07-06 08:19:29 0
  • Please take notice that if you are going to use an JPG file for shadow effect, let change -background none to -background white! Because -background none make a transparent effect while JPG doesn't support transparent! And when viewing, you will get a bacl box! So we will use an white background under! We can use other color as well!


    7
    convert {$file_in} \( +clone -background black -shadow 60x5+10+10 \) +swap -background none -layers merge +repage {$file_out}
    kureikain · 2009-05-06 10:19:39 3
  • Say you're started "xzcat bigdata.xz | complicated-processing-program >summary" an hour ago, and you of course forgot to enable progress output (you could've just put "awk 'NR%1000==0{print NR>"/dev/stderr"}{print}'" in the pipeline but it's too late for that now). But you really want some idea of how far along your program is. Then you can run the above command to see how many % along xzcat is in reading the file. Note that this is for the GNU/Linux version of lsof; the one found on e.g. Darwin has slightly different output so the awk part may need some tweaks. Show Sample Output


    2
    f=bigdata.xz; calc "round($(lsof -o0 -o "$f"|awk '{o=substr($7,3)}END{print o}')/$(stat -c %s "$f")*100)"
    unhammer · 2015-09-19 18:27:12 3
  • For automated unit tests I wanted my program to run normally, but if it crashed, to add a stack trace to the output log. I came up with this command so I wouldn't have to mess around with core files. The one downside is that it does smoosh your program's stderr and stdout together. Show Sample Output


    13
    gdb -batch -ex "run" -ex "bt" ${my_program} 2>&1 | grep -v ^"No stack."$
    kurt · 2010-12-29 17:46:31 0

What Others Think

That one is the heart of the trick and is more readable : find &> /tmp/test &
sputnick · 466 weeks and 3 days ago
But there's shorter : command > file & no need to put STDERR in the file, like that you'll see errors when running the command. ( "&> file" is a shortcut for "> file 2>&1" )
sputnick · 466 weeks and 3 days ago

What do you think?

Any thoughts on this command? Does it work on your machine? Can you do the same thing with only 14 characters?

You must be signed in to comment.

What's this?

commandlinefu.com is the place to record those command-line gems that you return to again and again. That way others can gain from your CLI wisdom and you from theirs too. All commands can be commented on, discussed and voted up or down.

Share Your Commands



Stay in the loop…

Follow the Tweets.

Every new command is wrapped in a tweet and posted to Twitter. Following the stream is a great way of staying abreast of the latest commands. For the more discerning, there are Twitter accounts for commands that get a minimum of 3 and 10 votes - that way only the great commands get tweeted.

» http://twitter.com/commandlinefu
» http://twitter.com/commandlinefu3
» http://twitter.com/commandlinefu10

Subscribe to the feeds.

Use your favourite RSS aggregator to stay in touch with the latest commands. There are feeds mirroring the 3 Twitter streams as well as for virtually every other subset (users, tags, functions,…):

Subscribe to the feed for: