C Program to execute programs in same console

usleepless at gmail.com usleepless at gmail.com
Wed Apr 5 06:29:46 UTC 2006


Hi Jon,

could you give another example ( not cd ) of a command which you would
like to execute in the calling shell?

regards,

usleep

On 4/5/06, Jonathan Herriott <herriojr at gmail.com> wrote:
> usleep,
>
> What I am trying to do is execute the command in the calling shell.
> So, if I were to execute my program, which changes the directory, it
> would do the following:
>
> > pwd
> /usr/home/username/
> > ./myprog ..
> > pwd
> /usr/home/
>
> That's basically what I'm looking for.  Being able to modify the
> calling shell with a program.
>
> Thanks,
> Jon
>
> On 4/4/06, usleepless at gmail.com <usleepless at gmail.com> wrote:
> > Jon,
> >
> > i believe you are mixing up some concepts.
> >
> > 1. if i read your title "C Program to execute programs in same
> > console". i think this is easy, just use system("ls *.txt") and you
> > are done. i believe you can choose wat to do with the output, i am not
> > sure.
> >
> > 2. but you come up with the cd-command, which you want to change the
> > context of your parent shell.  changing the home-dir of the current
> > process ( your program ) can be done with chdir. altering the context
> > of your parent-shell-process can not be done, except for setting
> > environment variables ( through the proper C calls )
> >
> > but if you are running your program, your "shell" (interpreter) is
> > temporarily not there:  your program is running the show. every
> > system,execvp or whatever call will give you a child-process with a
> > new shell, not the parent-shell-process. i believe you may set
> > environment variables in your parent shell with the appropiate library
> > calls, but not through a system/execvp call.
> >
> > so, maybe you should define what you really want to achieve. for
> > example, qdvd-author runs alls kinds of external programs to generate
> > thumbnails and slideshows for example.
> >
> > anybody please correct me if i am wrong.
> >
> > regards,
> >
> > usleep
> >
> >
> > On 4/4/06, Jonathan Herriott <herriojr at gmail.com> wrote:
> > > Thanks for the suggestion.  I haven't tried it yet, but I'll post if I
> > > get it working.
> > >
> > > Thanks,
> > > Jon
> > >
> > > On 4/3/06, cpghost <cpghost at cordula.ws> wrote:
> > > > On Mon, Apr 03, 2006 at 05:45:19PM -0400, Bill Moran wrote:
> > > > > On Mon, 3 Apr 2006 21:39:11 +0000
> > > > > "Jonathan Herriott" <herriojr at gmail.com> wrote:
> > > > > > So, my question is how can I get it to execute a cd in the
> current
> > > > > > shell using c code.  You don't have to give me the code, just give
> me
> > > > > > a term to search for or a function to look up.  I'm sure someone
> knows
> > > > > > how to do it here!
> > > > >
> > > > > Unless I'm misunderstanding your question, "man 2 chdir" should
> help
> > > out.
> > > >
> > > > Hmmm... chdir(2) would not change the parent process' (the shell's
> > > > process) current working directory, only the current working
> directory
> > > > of the process running the C program.
> > > >
> > > > Perhaps connecting to the shell via a pty, and then sending it a 'cd'
> > > > command could work? Of look at how expect(1) (/usr/ports/lang/expect)
> > > > implements this kind of stuff...
> > > >
> > > > Regards,
> > > > -cpghost.
> > > >
> > > > --
> > > > Cordula's Web. http://www.cordula.ws/
> > > >
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> > >
> >
>


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