lipsum/lipsum.c

#include <stdio.h>
#include <stdlib.h>
#include <time.h>
#include <stdbool.h>

/* Read a line from a file into a newly created buffer */
int readline(FILE* in, char **out) {
    int size_of_buffer = 20;
    char *buffer = calloc(size_of_buffer, sizeof(char));
    char character;
    int count = 0;

    while (true) {
        character = fgetc(in);        
        if (character == EOF) {
            buffer[count] = '\0';
            *out = buffer;
            return EOF;
        }
        if (character == '\n') {
            buffer[count] = '\0';
            *out = buffer;
            return 0;
        } else {
            if (count == (size_of_buffer - 3)) {
                buffer = reallocarray(buffer, (size_of_buffer *= 2),  
                        sizeof(char));

                if (!buffer) {
                    return 1;
                }
            }

            buffer[count] = character;
            count++;
        }
    }
}

char **read_word_file(FILE *words, int *num_ret) {
    rewind(words);
    int listlen = 10;
    char **wordlist = calloc(listlen, sizeof(char *));

    int no;
    for (no = 0; true; no++) {
        if (no == listlen) {
            listlen += 1;
            wordlist = reallocarray(wordlist, listlen, sizeof(char*));
            char *nextword;
            int er = readline(words, &nextword);

            if (er == EOF) {
                break;
            }

            wordlist[no] = nextword;
        }
    }

    *num_ret = no;
    return wordlist;
}

int main (int argc, char **argv) {
    if (argc > 2) {
        fprintf(stderr, "Usage: lipsum <num words>\n");
        return 1;
    }

    int num;

    if (argc == 1) {
        num = 50;
    } else {
        num = atoi(argv[1]);
        if (num <= 0) {
        fprintf(stderr, "Usage: lipsum <num words>\n");
        return 1;
        }
    }

    unsigned int rand_seed = time(NULL);

    int len;

    FILE *words = fopen("/usr/share/dict/words", "r");
    if (!words) {
        words = fopen("/usr/dict/words", "r");
    }
    if (!words) {
        fprintf(stderr, "No words file found\n");
        return 1;
    }

    char **wordlist = read_word_file(words, &len);
    fclose(words);

    for (int i = 0; i < num; i++) {
        int index = rand_r(&rand_seed) % len;
        printf("%s ", wordlist[index]);
    }
    printf("\n");
}