Proc::SafeExec provides an easy, safe way to execute external programs. It
replaces all of Perl's questionable ways of accomodating this, including
system(), open() with a pipe, exec(), back-ticks, etc. This module will
never automatically invoke /bin/sh. This module is easy enough to use that
/bin/sh should be unnecessary, even for complex pipelines.

For all errors, this module dies setting $@.

Errors from exec() in the child are reported gracefully to the parent. This
means that if anything fails in the child, the error is reported through $@
with die just like any other error. This also reports $@ if child_callback
dies when it is called between fork() and exec(). This is accomplished by
passing $@ through an extra pipe that's closed when exec succeeds. Note: A
side-effect of this is $@ is stringified if it isn't a string.