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#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <stdbool.h>
#include <ctype.h>
size_t getargs(const size_t n, char *args[n], FILE * const stream);
int shellexec(size_t n, char * const args[n]);
static bool run = true;
int main(int argc, char *argv[]) {
char *words[BUFSIZ] = {NULL};
FILE *fp = stdin;
size_t numberofwords = 0;
if (argc == 2) {
if ((fp = fopen(argv[1], "r")) == NULL) {
perror("jsh");
return EXIT_FAILURE;
}
}
while (run) {
printf("$ ");
numberofwords = getargs(BUFSIZ, words, fp);
shellexec(BUFSIZ, words);
for (int i = 0; i < numberofwords; i++) {
free(words[i]);
words[i] = NULL;
}
}
return 0;
}
size_t getargs(const size_t n, char *args[n], FILE * const stream) {
size_t i = 0;
char c = 0, s[BUFSIZ], *sp = s;
memset(s, '\0', sizeof(s));
while ((c = fgetc(stream)) != EOF && i < n && sp < s + BUFSIZ) {
if (isspace(c)) {
*sp = '\0';
args[i++] = strdup(s);
sp = s;
if (strcmp(args[i-1], "") == 0) {
free(args[i-1]);
args[i-1] = NULL;
i--;
}
if (c == '\n') {
break;
}
} else {
*sp++ = c;
}
}
return i;
}
int shellexec(size_t n, char * const args[n]) {
if (strcmp(args[0], "exit") == 0) {
run = false;
return 0;
}
pid_t pid = fork();
int status;
if (pid == 0) {
if (execvp(args[0], args) == -1) {
perror("jsh");
}
exit(EXIT_FAILURE);
} else if (pid < 0) {
perror("jsh");
exit(EXIT_FAILURE);
} else {
do {
waitpid(pid, &status, WUNTRACED);
} while (!WIFEXITED(status) && !WIFSIGNALED(status));
}
return 0;
}
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