C library for commands execution - development files

 s2argv converts a command string into an argv array for execv, execvp,
 execvpe. execs is like execv taking a string instead of an argv.
 Similarly execsp and execspe are the counterpart of execvp and execvpe,
 respectively, using command strings.
 coprocv, coprocvp, coprocvpe, coprocs, coprocsp execute a command in
 coprocessing mode.
 The following functions all work without using a shell:
 esystem, system_eexecsp execute a command with its arguments from a string.
 popen_nosh, popen_execsp and pclose_nosh pipe stream to or from a process.
 system_nosh executes a command with its arguments from a string.
 .
 This package contains the necessary headers and shared object files needed to
 develop applications using libexecs.