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#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/wait.h>
#include <unistd.h>
#include "array.h"
#include <stdbool.h>
void print_prompt();
int parse_line(char const *line, char **exe, char ***parts, size_t *part_count);
// returns the return code of the executed program
int exec_command(const char *path, char *const argv[], unsigned timeout);
int main(int argc, char* argv[]) {
while (true) {
char *line = NULL;
size_t cap = 0;
size_t length = 0;
print_prompt();
if ((length = getline(&line, &cap, stdin)) < 0) {
fprintf(stderr, "Failed to read from STDIN");
exit(-1);
}
line[length - 1] = '\0'; // cut the line feed
char *exe = NULL;
char **arguments = NULL;
size_t argument_count;
parse_line(line, &exe, &arguments, &argument_count);
if (strcmp(exe, "cd") == 0) {
printf("Changing dirs \n");
chdir("beispiele");
} else if (strcmp(exe, "exit") == 0) {
exit(0);
} else {
exec_command(exe, arguments, 0);
}
free((void *)line);
// no need to free exe, since it is part of arguments any way
arrayRelease(arguments);
}
}
int parse_line(char const *line, char **exe, char ***parts, size_t *part_count) {
char *part;
char **local_parts;
if (arrayInit(part) != 0 || arrayInit(local_parts) != 0) {
fprintf(stderr, "Failed to prepare new part array");
exit(-1);
}
bool found_exe = false;
char c;
int i = 0;
while (true) {
c = line[i++];
if (c == ' ' || c == '\0') {
arrayPush(part) = '\0';
arrayPush(local_parts) = part;
if (!found_exe) {
// the first is the executable
*exe = malloc(arrayLen(part) * sizeof(char));
strcpy(*exe, part);
found_exe = true;
}
arrayInit(part);
if (c == '\0') {
arrayPush(local_parts) = NULL;
break;
}
} else {
arrayPush(part) = c;
}
}
*part_count = arrayLen(local_parts);
*parts = local_parts;
return 0;
}
void print_prompt() {
size_t length = 1024;
char *buffer = malloc(length * sizeof(char));
getcwd(buffer, length);
if (buffer == NULL) {
printf(".> ");
} else {
printf("%s > ", buffer);
}
}
int exec_command(const char *path, char *const argv[], unsigned timeout) {
int pid;
int pipefd[2];
int status;
char buf[512];
pipe(pipefd);
if ((pid = fork()) == 0) {
close(pipefd[0]);
dup2(pipefd[1], 1); // includes close(1);
close(pipefd[1]);
execvp(path, argv);
fprintf(stderr, "no program\n");
exit(-1);
}
if (pid < 0) {
fprintf(stderr, "no fork\n");
exit(-2);
}
close(pipefd[1]);
size_t length = 0;
while ((length = read(pipefd[0], buf, 10)) > 0) {
buf[length] = '\0';
printf("%s", buf);
}
waitpid(pid, &status, 0);
close(pipefd[0]);
return WEXITSTATUS(status);
}
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