174 lines
2.9 KiB
C
174 lines
2.9 KiB
C
#include <sys/types.h>
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#include <sys/stat.h>
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#include <fcntl.h>
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#include <stdio.h>
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#include <assert.h>
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#include <unistd.h>
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#include <string.h>
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#include <stdlib.h>
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void lire(char **, char **, char **);
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char * lireChaine3();
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void changeDirectory(char * path);
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int subString (const char *chaine, int debut, int fin, char *result);
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void erreur(char *s);
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void executionArrierePlan(char *arg1);
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void execution(char *arg1, char *arg2, char *arg3);
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int main(int argc, char **argv)
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{
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int commandeInterne;
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char *arg1, *arg2, *arg3;
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// Boucle principale qui attend les commandes
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while(1)
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{
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printf("[ %s ] %s $ ",(char *) getenv("USER"), (char *) getenv("PWD"));
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arg1 = arg2 = arg3 = NULL;
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commandeInterne = 0;
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lire(&arg1, &arg2, &arg3);
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if(strcmp(arg1, "cd") == 0)
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{
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commandeInterne = 1;
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// On change de répertoire
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changeDirectory(arg2);
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}
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if(strcmp(arg1, "exit") == 0)
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{
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commandeInterne = 1;
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exit(0);
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}
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if(commandeInterne == 0)
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{
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execution(arg1, arg2, arg3);
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}
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}
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}
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void execution(char *arg1, char *arg2, char *arg3)
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{
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int pid;
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if(arg2 != NULL)
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{
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if(strcmp(arg2, "&") == 0)
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executionArrierePlan(arg1);
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if(strcmp(arg2, "<") == 0)
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{
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printf("Commande avec <\n");
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}
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}
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else // exécution basique
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{
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if((pid = fork()) == 0)
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{
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execv(arg1, NULL);
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erreur("Soucis au niveau du exec");
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exit(-2);
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}
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else
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waitpid(pid);
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}
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}
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void changeDirectory(char * path)
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{
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if(path == NULL || strcmp(path, "") == 0)
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{
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chdir(getenv("HOME"));
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setenv("PWD", (char *) getenv("HOME"), 1);
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}
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else
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{
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if(chdir(path) != 0)
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erreur("Impossible de changer de répertoire");
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else
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setenv("PWD", path, 1);
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}
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}
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void lire(char** arg1, char** arg2, char** arg3)
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{
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char *s;
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s = lireChaine3();
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*arg1 = strtok(s," ");
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*arg2 = strtok((char *)0," ");
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*arg3 = strtok((char *)0," ");
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}
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char *lireChaine3()
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{
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char *ptr, *ptr1;
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int c;
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int i=0;
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int nb=10;
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ptr=malloc(nb);
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assert(ptr);
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while((c=getchar()) != '\n' && c != EOF)
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{
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if (i==nb-1)
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{
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ptr1=malloc(nb=nb*2);
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assert(ptr1);
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ptr[i]='\0';
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strcpy(ptr1,ptr);
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free(ptr);
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ptr=ptr1;
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}
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ptr[i]=c;
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i++;
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}
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ptr[i]='\0';
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if(c == EOF && i == 0)
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ptr = NULL;
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else
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if (i+1 != nb)
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{
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ptr1=malloc(i+1);
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assert(ptr1);
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strcpy(ptr1,ptr);
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free(ptr);
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ptr=ptr1;
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}
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return ptr;
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}
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void erreur(char *s)
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{
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perror(s);
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}
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int subString (const char *chaine, int debut, int fin, char *result)
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{
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result[fin+1-debut] = '\0';
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memcpy (result, (char *)chaine+debut, fin+1-debut);
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return (fin+1-debut);
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}
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void executionArrierePlan(char *arg1)
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{
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int pid;
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int pipefd[2];
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pipe(pipefd);
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if((pid = fork()) == 0)
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{
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if((pid = fork()) == 0)
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{
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close(pipefd[1]);
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int temp, fd0, fd1, fd2, pid;
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if((fd0 = open("/dev/null", O_RDONLY)) == -1)
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{
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erreur("Ouverture fichier null");
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exit(-2);
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}
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exit(0);
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}
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else
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{
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close(pipefd[0]);
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}
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}
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else
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{
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}
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}
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