Alpha version of GNU Parallel 20110607 released

[Ole Tange]

The GNU Parallel 20110607 alpha release can be fetched at:
http://alpha.gnu.org/gnu/parallel/parallel-20110607.tar.bz2

Please test it thoroughly so we are sure nothing is broken. It passes
the testsuite, so it should be production quality.

GNU Parallel has so far not had a mode for running the same command on
all remote computers given with -S. This version changes that.

With --onall all the commands will be run on all computers:

  parallel --onall -S server1,server2 touch /tmp/{1}-{2} ::: a b ::: X Y

If the command you want to run does not take any arguments you can use --nonall:

  parallel --nonall -S server1,server2 uptime

This version also implements --minversion which is useful for scripts
that may depend on GNU Parallel be of a specific version or higher:

  parallel --minversion 20110506 && echo GNU Parallel is newer than or
equal to version 20110506
  parallel --minversion 20120506 || echo GNU Parallel is not newer
than version 20120506

If you use GNU Parallel for running memory hungry programs, you will
probably appreciate --noswap:

  parallel --noswap your_memory_hungry_program ::: a b c

This will run your_memory_hungry_program unless your system is
swapping both in and out - which is usually an indication that your
system is out of physical memory. It will test every 10 seconds and
try again then.

If you use GNU niceload for running memory hungry programs, you will
probably appreciate --noswap, --mem, and --hard:

   niceload --hard --load 2 your_cpu_hungry_program

niceload will normally slow down a program, but with --hard it will
suspend the program until the limit is reached (e.g. the load is below
the given limit). The program will be started but only run for very
few milliseconds before being suspended.

--mem makes is possible to only run a program if there is this amount
of memory free:

  niceload --hard --mem 2g this_program_requires_2g_ram_to_run

--noswap works similar to --noswap in GNU Parallel: if the machine is
swapping slow down or do not run the program.

  niceload --hard --noswap dont_run_this_program_if_swapping

Let me know if you find bugs in these.

/Ole