Pexec

The most common usage is to replace the shell loop, for example:

for x in alpha bravo charlie delta ; do do_something $x done

to the form of:

pexec -r alpha bravo charlie delta -e x -o - -c \ 'do_something $x'

where the set with the 4 elements of "alpha" "bravo" "charlie" and "delta" define the possible values for the (environmental) variable $x. The program pexec features also

• automatic redirection of standard input, output and error from/to regular files;
• taking the input set from a file instead of command line argument;
• the capability for re-formatting the output and error streams;
• support for mutual exclusions and atomic command executions inside the shell loop (in order to, e.g. avoid unexpectedly high I/O load);
• using alternative remote shells instead of ssh.
• using supervisor daemons to balance between the resources of concurrent pexec instances.

Such optional features can be requested using command-line arguments. By default, pexec tries to detect the number of CPUs and uses all of them.