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#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <stdbool.h>
#include <wait.h>
#include <errno.h>
#include "array.h"
#include "process.h"
#include "prompt_utils.h"
void handle(int sig) {
/* Do nothing. */
}
int main(void) {
setvbuf(stderr, NULL, _IONBF, 0);
setvbuf(stdout, NULL, _IONBF, 0);
struct sigaction handler;
handler.sa_handler = handle;
sigemptyset(&handler.sa_mask);
handler.sa_flags = 0;
printf("Welcome! Available built-ins are:\n"
"cd: `cd <path>` - if no path is given, return to the current dir\n"
"wait: `wait pid1 ... pidN` - wait on the processes and report their exit conditions\n"
"fg: `fg pid` - pulls a process from the background back in the foreground (#TODO)\n"
"\n"
"You can put processes in the background using the unary `&` for new processes, and using CTRL-Z (#TODO) for already running ones\n"
"With `|` you can pipe the output from one process to the input of another\n"
);
char const *const original_wd = get_current_dir_name();
char const *prompt = relative_path(original_wd, original_wd);
bool done = false;
while (!done) {
char *line = NULL;
size_t cap = 0;
__ssize_t length = 0;
printf("%s > ", prompt);
if ((length = getline(&line, &cap, stdin)) < 0) {
fprintf(stderr, "Failed to read from STDIN");
fflush(stderr);
exit(-1);
}
if (strspn(line, " \n\t") == strlen(line)) {
// skip empty lines - empty being just spaces or tabs
continue;
}
line[length - 1] = '\0'; // cut the line feed
process *processes = NULL;
parse_line(line, &processes);
if (strcmp(processes[0].argv[0], "cd") == 0) {
if (arrayLen(processes) != 1) {
perror("Can't chain cd with other processes");
}
int ret;
switch(arrayLen(processes[0].argv)) {
case 3:
ret = chdir(processes[0].argv[1]);
break;
case 2:
ret = chdir(original_wd);
break;
default:
fprintf(stderr, "usage: cd <path>\n");
fflush(stderr);
ret = -1;
}
if (ret)
printf("[%i] ", ret);
free((void *)prompt);
char const *current_wd = get_current_dir_name();
prompt = relative_path(original_wd, current_wd);
free((void *)current_wd);
} else if (strcmp(processes[0].argv[0], "exit") == 0) {
done = true;
} else if (strcmp(processes[0].argv[0], "wait") == 0) {
bool error = false;
pid_t *pids;
arrayInit(pids);
size_t i = 1;
while (!error && processes[0].argv[i] != NULL) {
char *end;
pid_t tmp = strtol(processes[0].argv[i], &end, 10);
if (*end != '\0') {
fprintf(stderr, "Not a valid pid: %s", processes[0].argv[i]);
error = true;
break;
}
arrayPush(pids) = tmp;
++i;
}
if (!error) {
while (!arrayIsEmpty(pids)) {
int status;
pid_t current_pid = arrayPop(pids);
printf("Waiting for %ld...\n", (long) current_pid);
// install signal handler without SA_RESTART, so waitpid gets interrupted
sigaction(SIGINT, &handler, NULL);
if (waitpid(current_pid, &status, WUNTRACED) < 0) {
if (EINTR == errno) {
// cancelled by ctrl-c
} else {
perror("Could not wait on process");
}
} else {
printf("[%i] TERMINATED\n", current_pid);
if (WIFEXITED(status)) {
printf("[%i] exited normally with status: %i\n", current_pid, WEXITSTATUS(status));
} else if (WIFSTOPPED(status)) {
printf("[%i] was stopped by signal: %s\n", current_pid, strsignal(WSTOPSIG(status)));
} else if (WIFSIGNALED(status)) {
printf("[%i] was terminated by signal: %s\n", current_pid, strsignal(WTERMSIG(status)));
} else {
printf("[%i] exited (not sure why), exit status: %i\n", current_pid, WEXITSTATUS(status));
}
}
signal(SIGINT, SIG_DFL);
}
}
arrayRelease(pids);
} else {
for (size_t i = 0; i < arrayLen(processes); ++i) {
int ret = exec_command(processes[i]);
if (ret)
printf("[%i] ", ret);
}
}
free((void *)line);
line = NULL;
cap = 0;
free_processes(&processes);
}
free((void *)original_wd);
free((void *)prompt);
}
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