ap_call_exec — exec, spawn, or call setuid wrapper
int ap_call_exec(request_rec *r, child_info *pinfo, char *argv0, char **env, int shellcmd)
Calls exec() (or an appropriate spawning function
on nonforking platforms) or the setuid wrapper,
depending on whether setuid wrappers are
enabled. argv0 is the name of the program to run;
env is a NULL-terminated array
of strings to be used as the environment of the
execed program. If shellcmd is
nonzero, the command is run via a shell. If
r->args is set and does not contain an equal
sign, it is passed as a command-line argument.
pinfo should be the structure passed by
ap_bspawn_child(). This function should not
return on forking platforms. On nonforking platforms it returns the
PID of the new process.