SO #4

#include <stdio.h>
#include <stdlib.h>
#include <fcntl.h>
#include <string.h>

int main(int argc, char *args[]) {
    if(argc != 3) {
      printf("Usage: %s <file> <output directory>\n", args[0]);
      exit(1);
    }
    char buffer[20];
    char *output_dir;
    output_dir = (char *) malloc((sizeof(args[2])+sizeof(args[1]))*sizeof(char));

    strcat(output_dir, args[2]);
    strcat(output_dir, "/");
    strcat(output_dir, args[1]);


    int file = open(args[1], O_RDONLY, S_IRUSR|S_IWUSR);
    if(file == -1) {
      printf("Could not open input file\n");
    }

    int digit_count = 0;
    int even_digit_count = 0;

    while(read(file, buffer, sizeof(buffer))) {
      int i;
      for(i=0; buffer[i]; i++) {
    if(isdigit(buffer[i])) {
      digit_count++;
      if((int)(buffer[i]-'0') % 2 == 0) {
        even_digit_count++;
      }
    }
      }
    }
    char report_string[128];
    sprintf(report_string, "Digit count: %d | Even digit count: %d\n", digit_count, even_digit_count);
    close(file);
    file = open(output_dir, O_CREAT|O_WRONLY|O_TRUNC, S_IRUSR|S_IWUSR);
    if(file == -1) {
      printf("Error while opening output file!\n");
      exit(1);
    }
    if(write(file, report_string, strlen(report_string)/sizeof(char)) == -1) {
      printf("Error while writing report!\n");
      exit(1);
    }
    printf("Report generated\n");
    exit(0);
}