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/* sh - the standard command language interpreter
* Copyright (C) 2022 Ferass EL HAFIDI
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* 1. Redistributions of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the copyright holder nor the names of its
* contributors may be used to endorse or promote products derived from
* this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/
#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 (argc == 0) return 0; /* There's no argument. */
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-256 == -E2BIG || err-256 == -EACCES || err-256 == -EINVAL ||
err-256 == -ELOOP ||
err-256 == -ENAMETOOLONG || err-256 == -ENOENT || err-256 == -ENOTDIR)
printf("sh: %s: %s\n", argv[0], strerror(-(err-256)));
return err;
}
/* 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 && token[0] != '#')
splitted_name[0] = token;
else return 0;
/* WARNING: Not thread-safe! */
for (; (token = strtok(NULL, " ")) != NULL &&
token[0] != '#' &&
(splitted_name[array_index] = token); array_index++)
/* Do nothing. */ ;
return array_index;
}
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