=head1 IDEAS

One char options not used: F G J K M P Q Y

Test if -0 works on filenames ending in '\n'

xargs dropin-replacement.
Implement the missing --features

monitor to see which jobs are currently running
http://code.google.com/p/ppss/

Accept signal INT instead of TERM to complete current running jobs but
do not start new jobs. Print out the number of jobs waiting to
complete on STDERR. Accept sig INT again to kill now. This seems to be
hard, as all foreground processes get the INT from the shell.

If there are nomore jobs (STDIN is closed) then make sure to
distribute the arguments evenly if running -X.


Distribute jobs to computers with different speeds/number-of-cpu-cores using ssh
ask the computers how many cpus they have and spawn appropriately
according to -j setting.  Reuse ssh connection (-M and -S)

Start by porting everything to use sshlogin :.

SEED=$RANDOM
ssh -MS /tmp/ssh-%r@%h:%p-$SEED elvis
rsync --rsh="ssh -S /tmp/ssh-%r@%h:%p-$SEED"  gitup elvis:/tmp/
ssh -S /tmp/ssh-%r@%h:%p-$SEED elvis hostname

FILE=gpl-3.0.txt
BASE=gpl-3.0
$ rsync -z $FILE e:$FILE
$ ssh e "cat $FILE | bzip2 > $BASE.bz2"
$ rsync -z e:$BASE.bz2 $BASE.bz2
$ ssh e "rm $FILE $BASE"

http://www.semicomplete.com/blog/geekery/distributed-xargs.html?source=rss20
http://code.google.com/p/ppss/wiki/Manual2

http://www.gnu.org/software/pexec/

Where will '>' be run? Local or remote? Remote.


Parallelize so this can be done:
mdm.screen find dir -execdir mdm-run cmd {} \;
Maybe:
find dir -execdir par$ --communication-file /tmp/comfile cmd {} \;

=head2 Comfile

This will put a lock on /tmp/comfile. The number of locks is the number of running commands.
If the number is smaller than -j then it will start a process in the background ( cmd & ),
otherwise wait.

par$ --wait /tmp/comfile will wait until no more locks on the file

=head2 mutex

mutex -n -l lockid -m max_locks [command]
mutex -u lockid

-l lockfile will lock using the lockid
-n nonblocking
-m maximal number of locks (default 1)
-u unlock

If command given works like: mutex -l lockfile -n number_of_locks ; command; mutex -u lockfile