C library for commands execution
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.