/*
 * Program to find "words" (sequences of "isalpha" characters).
 *
 * Input is a text file.
 *
 * Output is a text file with the "words" from the input file, 
 *   in lowercase, one per line.
 *
 * Names for the two files are given as command-line arguments.
 *
 * Also print (to stdout) totals of alphabetic characters and all 
 *   characters.
 */
#include <stdio.h>
#include <ctype.h>
#include <stdbool.h>

int main(int argc, char *argv[]) {

    if (argc < 3) {
        printf("usage %s infile outfile\n", argv[0]);
        return 1;
    }
    FILE * infile = fopen(argv[1], "r");
    if (infile == NULL) {
        printf("cannot open input file\n");
        return 1;
    }
    FILE * outfile = fopen(argv[2], "w");
    if (outfile == NULL) {
        printf("cannot open output file\n");
        return 1;
    }

    int inchar;
    int count = 0;
    int alphacount = 0;
    bool inword = false;
    while ((inchar = fgetc(infile)) != EOF) {
        count += 1;
        if (isalpha(inchar)) {
            alphacount += 1;
            inword = true;
            fputc(tolower(inchar), outfile);
        } else {
            if (inword) fputc('\n', outfile);
            inword = false;
        }
    }

    fclose(infile);
    fclose(outfile);

    printf("%d alphabetic characters, %d characters in all\n", 
            alphacount, count);
    return 0;
}