/*
 * World's simplest shell.
 * Loops, reads input and tries to execute it.
 * Note: no tokenization, can be ^C'd, but does look at PATH
 *       not sorted
 *
 * ./simple-shell
 * $$ ls
 * $$ /bin/ls
 * $$ /bin/ls -la # error
 * $$ ^C
 *
 */

#include <sys/types.h>
#include <sys/wait.h>
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sysexits.h>
#include <unistd.h>

char *
getinput(char *buffer, size_t buflen) {
	printf("$$ ");
	return fgets(buffer, buflen, stdin);
}

int
main(int argc, char **argv) {
	char buf[1024];
	pid_t pid;
	int status;

	while (getinput(buf, sizeof(buf))) {
		buf[strlen(buf) - 1] = '\0';

		if((pid=fork()) == -1) {
			fprintf(stderr, "shell: can't fork: %s\n",
					strerror(errno));
			continue;
		} else if (pid == 0) {
			/* child */
			execlp(buf, buf, (char *)0);
			fprintf(stderr, "shell: couldn't exec %s: %s\n", buf,
					strerror(errno));
			exit(EX_DATAERR);
		}

		if ((pid=waitpid(pid, &status, 0)) < 0)
			fprintf(stderr, "shell: waitpid error: %s\n",
					strerror(errno));
	}

	exit(EX_OK);
}