Bug#572325: ITP: xjobs -- reads job descriptions line by line and executes them in parallel

[Stefan Voelkel <bd@bc-bd.org>]

Package: wnpp
Severity: wishlist
Owner: Stefan Voelkel <bd@bc-bd.org>


* Package name    : xjobs
  Version         : 20100203
  Upstream Author : Thomas Maier-Komor <thomas@maier-komor.de>
* URL             : http://www.maier-komor.de/xjobs.html
* License         : GPL
  Programming Lang: C
  Description     : reads job descriptions line by line and executes them in parallel

 It limits the number of parallel executing jobs and starts new jobs when jobs
 finish. Therefore, it combines the arguments from every input line with the
 utility and arguments given on the command line. If no utility is given as an
 argument to xjobs, then the first argument on every job line will be used as
 utility. To execute utility xjobs searches the directories given in the PATH
 environment variable and uses the first file found in these directories.
 .
 xjobs is most useful on multi-processor/core machines when one needs to
 execute several time consuming command several that could possibly be run in
 parallel. With xjobs this can be achieved easily, and it is possible to limit
 the load of the machine to a useful value. It works similar to xargs, but
 starts several processes simultaneously and gives only one line of arguments
 to each utility call.

>From the webpage:

Comment on GNU xargs vs. xjobs

Yes, GNU's xargs has an option -P that allow parallelizing jobs. But you must
tell xargs how many arguments to pass to each job, as it doesn't make a
difference between a space and a newline charakter. In consequence each job
issued by xargs must have the same number of arguments, whereas xjobs can
handle different jobs with different commands and different number of
arguments.

Additionally, xjobs support I/O redirection, which makes some applications
possible that cannot be done with GNU's xargs. xjobs also determines the number
of processors automatically, whereas xargs must be told how many processes to
start. Finally, non-GNU xargs (e.g. Solaris' and DEC/Compaq/HP Alpha's) don't
have the option -P. Try to do the following with GNU's xargs with some files
having blanks in their name:

    * ls -1 *.mp3 | sed 's/\(.*\)\.mp3/"\1.mp3" > "\1.wav"/' | xjobs -- mpg123 -s

If you aren't convinced yet, just compare the output of unziping multiple zip
files in parallel with xjobs and GNU xargs. xjobs won't intermix the output of
unzip like xargs. Instead it will present the output of each unzip separated
clearly from the other jobs. 

-- System Information:
Debian Release: 5.0.4
  APT prefers stable
  APT policy: (500, 'stable')
Architecture: i386 (i686)