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/* sh - the standard command language interpreter
* Copyright (C) 2022 Ferass EL HAFIDI
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <https://www.gnu.org/licenses/>.
*/
#define _POSIX_C_SOURCE 200809L
/* POSIX Header Files */
#include <unistd.h>
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <errno.h>
#include <signal.h>
/* sh Header Files */
#include "parser.h"
#include "commands.h"
int parseCommand(int, char **);
int splitCommand(char [4096], char *[4096]);
/* USAGE
* -----
* parseCommand(name);
*
* DESCRIPTION
* -----------
* Parse a shell command and determine if the command to run is built-in or
* external. It then runs the command accordinately.
* <It also could in the future handle tokens.>
*/
int parseCommand(int argc, char *argv[]) {
struct sigaction signal_action;
int status_code = 0, err = 0;
pid_t isparent;
if (!strcmp(argv[0], "cd")) return builtin_cd(argc, argv);
/* The command isn't built-in. */
isparent = fork();
wait(&status_code);
if (!isparent) {
/* Do not ignore SIGINT when in a child process. */
signal_action.sa_handler = SIG_DFL;
sigemptyset(&signal_action.sa_mask);
sigaction(SIGINT, &signal_action, NULL);
/* Some sh implementations manually search for the command in PATH.
* This is not needed here because execvp is going to search for
* that command in PATH anyway.
*/
status_code = execvp(argv[0], argv);
/* If the child process is still alive, we know execvp(3) failed. */
exit(errno);
}
/* This code may be used to store the exit value in $?. */
//if (errno != EINTR && WEXITSTATUS(status_code) !=) return WEXITSTATUS(status_code);
//else return 0;
err = WEXITSTATUS(status_code);
if (err == E2BIG || err == EACCES || err == EINVAL || err == ELOOP ||
err == ENAMETOOLONG || err == ENOENT || err == ENOTDIR)
return err;
return 0;
}
/* USAGE
* -----
* splitCommand(name, dest);
*
* DESCRIPTION
* -----------
* This splits a command string in multiple words.
* The array command can then be ran using execvp(3). It
* also returns an int that can be used as argc.
*/
int splitCommand(char name[4096], char *splitted_name[4096]) {
long unsigned int array_index = 1;
char *token;
if ((token = strtok(name, " ")) != NULL) splitted_name[0] = token;
/* WARNING: Not thread-safe! */
for (; (token = strtok(NULL, " ")) != NULL &&
(splitted_name[array_index] = token); array_index++)
/* Do nothing. */ ;
return array_index;
}
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