fish-shell/src/print_help.cpp

// Print help message for the specified command.
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include "common.h"
#include "print_help.h"

#define CMD_LEN 1024

#define HELP_ERR "Could not show help message\n"

void print_help(const char *c, int fd) {
    char cmd[CMD_LEN];
    int printed = snprintf(cmd, CMD_LEN, "fish -c '__fish_print_help %s >&%d'", c, fd);

    if (printed < CMD_LEN) {
        if ((system(cmd) == -1)) {
            write_loop(2, HELP_ERR, strlen(HELP_ERR));
        }
    }
}