On Thu, 2002-05-30 at 09:01, Siders, Keith wrote: > I was planning to use system() to invoke a shell and launch a script. > However it appears that this causes the parent process to terminate. A note > in Linux Programming Bible (Goerzen, 2000) says to never invoke a shell or > use the system() function. Having looked at fork() and exec(), these will > require obscene amounts of memory and overhead (for an embedded box). I'm not sure that fork() qualifies as an "obscene amount of overhead". That may have been true before copy-on-write, but the only thing vfork() saves you with respect to fork() is page table construction, which is not particularly memory or processor intensive. > I've > also looked at vfork() and execve(), which looks like it will do what I > want. So do I do the vfork()/execve() pair, or is there a better way? And > would sigaction() handling be the way to pass progress information from the > child back to the parent process? As a personal preference, I dislike vfork() since it's pretty nonstandard in its behaviour on linux. Generally, though, it sounds like maybe you'd benefit from a copy of Kernighan & Pike's _The Unix Programming Environment_. There are more ways to do interprocess communication than you can shake a stick at, and which one is "right" for you depends largely on your specific application. Signals is a reasonable way (though if you vfork() you won't be able to handle signals in your parent concurrent with the child running...). There are also named pipes, shared memory, SysV messaging... -Justin
