qments/examples/leave_comment.c

/* Reads text from stdio and creates comment using unix fs driver in current directory */

#include <stdio.h>
#include <time.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <pwd.h>
#include <sys/types.h>

#include "comment.h"
#include "driver.h"
#include "drivers/unix_fs/unix_fs_driver.h"

char *
get_username()
{
    uid_t uid = geteuid();
    struct passwd *pw = getpwuid(uid);
    if (pw) {
        return pw->pw_name;
    }
    return "";
}

void
usage()
{
    fprintf(stderr, "Simple utility to leave comment using unix_fs_driver\n");
    fprintf(stderr, "usage: <tool-name> [-p path] [-r reply_id] [-d displayname] [-i input_file]\n");
    fprintf(stderr, "-p path:\t path to comment storage \n");
    fprintf(stderr, "-r reply_id:\t ID of comment you are replying to, 0 if yours is top-level\n");
    fprintf(stderr, "-d displayname:\t Displayname to attach to comment\n");
    fprintf(stderr, "-i input_file:\t File containing comment text(defaults to stdin)\n");
}

int
main(int argc, char *argv[])
{
    const Driver *driver = &unix_fs_driver;
    char *path = ".";

    char *user_sid = get_username();
    char *user_displayname = user_sid;
    char *text_filename = NULL;
    int reply_id = 0;
    
    int opt;
    while ((opt = getopt(argc, argv, "p:d:r:i:")) != -1) {
        switch (opt) {
        case 'p':
            path = optarg;
            break;
        case 'd':
            user_displayname = optarg;
            break;
        case 'r':
            reply_id = strtol(optarg, NULL, 10);
            if (reply_id < 0) {
                fprintf(stderr, "error: reply id can't be less than 0\n");
                usage();
                exit(EXIT_FAILURE);
            }
            break;
        case 'i':
            text_filename = optarg;
            break;
        default:
            usage();
            exit(EXIT_FAILURE);
        }
    }

    size_t cur_buf_size = 256;
    size_t idx = 0;

    char *text = malloc(cur_buf_size);

    FILE *input_stream = (text_filename ? fopen(text_filename, "r") : stdin);
    if (input_stream == NULL) {
        fprintf(stderr, "error: cannot open input file\n");
        perror("fopen");
        exit(EXIT_FAILURE);
    }

    int ch;
    while ((ch = getchar()) != EOF) {
        if (idx + 1 == cur_buf_size) {
            cur_buf_size *= 2;
            text = realloc(text, cur_buf_size);
        }
        text[idx++] = ch;
    }
    text[idx] = '\0';

    time_t current_time;
    time(&current_time);

    UnixFsDriverData driver_data = { path };

    CommentHeader *header = mk_comment_header(reply_id, current_time, strlen(text), user_sid, user_displayname);

    int retval = driver->leave_comment(&driver_data, header, text);
    free(text);
    if (retval < 0) {
        return retval;
    } else {
        return 0;
    }
}