60 lines
1.2 KiB
C
60 lines
1.2 KiB
C
|
#include <stdio.h>
|
||
|
|
#include <unistd.h>
|
||
|
|
#include <stdlib.h>
|
||
|
|
#include <signal.h>
|
||
|
|
#include <wait.h>
|
||
|
|
|
||
|
|
// utilise tube, fork, redirection E/S
|
||
|
|
|
||
|
|
// commande : voir enchainant l'execution d'une cde avec more
|
||
|
|
// exemple : ./voir ls -lR $HOME
|
||
|
|
|
||
|
|
int main(int argc, char **argv)
|
||
|
|
{
|
||
|
|
int p[2],pid;
|
||
|
|
|
||
|
|
if(argc < 2)
|
||
|
|
{
|
||
|
|
perror("erreur argument");
|
||
|
|
exit(-1);
|
||
|
|
}
|
||
|
|
|
||
|
|
if(pipe(p) == -1)
|
||
|
|
{
|
||
|
|
perror("erreur creation tube ");
|
||
|
|
exit(-2);
|
||
|
|
}
|
||
|
|
|
||
|
|
pid=fork(); // creation du proc. fils
|
||
|
|
|
||
|
|
switch(pid )
|
||
|
|
{
|
||
|
|
case -1:
|
||
|
|
perror("fork1");
|
||
|
|
exit(-3);
|
||
|
|
break;
|
||
|
|
|
||
|
|
case 0 : // le fils traite la commande
|
||
|
|
|
||
|
|
close(1);
|
||
|
|
dup(p[1]); // on recupere forcement le desc. 1 (+ petit possible)
|
||
|
|
close(p[0]);
|
||
|
|
close(p[1]);
|
||
|
|
execvp(argv[1],argv+1);
|
||
|
|
printf("\n*** erreur exec. impossible!");
|
||
|
|
exit(-4);
|
||
|
|
|
||
|
|
default: // le pere fait le "more"
|
||
|
|
|
||
|
|
close(0); // on ferme entree standard
|
||
|
|
dup(p[0]); // on connecte l'entree standard au tube
|
||
|
|
close(p[0]); // pour blocage en lecture
|
||
|
|
close(p[1]);
|
||
|
|
execlp("more","more",0); // si on saisit More par exemple -> message erreur
|
||
|
|
printf("\nerreur execution more \n");
|
||
|
|
exit(-5);
|
||
|
|
}
|
||
|
|
exit(0); // on ne vient jamais ici
|
||
|
|
}
|
||
|
|
|