build a shell

ej25 · 12-01-2004, 03:37 AM

Code:

 
#include <stdio.h>
#include <unistd.h>
#include <stdlib.h>
#include <sys/wait.h>

 

main (int argc, char *argv[] ){

	int i;
	int status;
	int c=1;
    int  forkresult ;
   
    forkresult = fork ( ) ;

     if (forkresult != 0)

            wait(&status);  
     

       else    
                          
            execvp (argv[1],&argv[1] );

              
      printf ("EXEC Failed\n") ;   
            
         exit(1);

}

I wrote this code which take as argment a command from the user and exexuit it

how can I make it loop for infinity and take each time a coomand from the user and how can I make it wait untiul the programme exits befor it print the promot again to recive the second coomand?

bigearsbilly · 12-01-2004, 03:49 AM

shouldn't it be:

Code:

wait (forkresult)

status is a non initialised variable.

billy

jlliagre · 12-01-2004, 04:43 AM

Quote:

shouldn't it be:
code:
wait (forkresult)
status is a non initialised variable.

wait(&status) is right, no need to initialize status as the call purpose is precisely to affect it.

Quote:

how can I make it loop for infinity and take each time a coomand from the user

Something like:

Code:

while(1)
{
printf(prompt);
command=fgets(buffer,SIZE,stdin);
...
fork stuff
...
}

Quote:

and how can I make it wait untiul the programme exits befor it print the promot again to recive the second coomand?

the wait call should be enough

DaZjorz · 12-02-2004, 07:01 AM

Cool, make your own shell... Heh

Is the bash-shell a big program? I mean, if the shell that this guy made is as good as that one then it would be nice heh

cuz that makes it very small and easy-to-compile

Are you going to build in some build-in programs?