/*****************************************************************************
 *
 * Program:  dirsize
 *
 * This C program simulates the dir/size command on a VMS machine.
 *
 * To compile and link this program in Linux/Unix:
 *
 *    > gcc -o dirsize dirsize.c
 *
 * Written by Don Luttermoser on  6 Jun 1995.
 *              Last modified on  7 Feb 1999
 *              Last modified on 13 Sep 2021.
 *              Last modified on 28 May 2025:
 *                - Reposition header words.
 *                - Added <ctype.h> to "include".
 *
 *****************************************************************************/

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

#define STRMAX 255
#define DIRMAX 255

int main(int argc, char *argv[])
{
  int count = 0, digcnt, i, c, nchar = 0;
  long int sz, szfile = 0, szvms;
  double fscale = 1.;
  char line[STRMAX], size[STRMAX], command[STRMAX], cdir[STRMAX], funit[10];
  FILE *fp, *fls;

  if ((fp = popen("pwd", "r")) != NULL) {     /* Get the directory name */
    i = 0;
    while (((c = getc(fp)) != EOF) && (i < STRMAX-1)) cdir[i++] = c;
    cdir[i] = '\0';
    fflush(fp);
    pclose(fp);
  } else {
    fprintf(stderr, "Error in reading contents of current directory.\n");
    exit(EXIT_FAILURE);
  }

  switch (argc) {
    case 1: 
      fls = popen("ls -l", "r"); /* Get a "long" listing of the files in dir */
      break;
    default:
      strcpy(command, "ls -l ");
      for (i = 0; i < argc; i++) {
        strcat(command, argv[i]);
        strcat(command, " ");
        if ((strchr(argv[i], '/')) != NULL) {  /* Check for different dir. */
          if (i == 1) {
            strcpy(cdir, argv[i]);
            strcat(cdir, " ");
          } else {
            strcat(cdir, argv[i]);
            strcat(cdir, " ");
          }
          strcat(cdir, "\n");
        }
      }
      fls = popen(command, "r");   /* Get a "long" listing of the files */
      break;
  }

  if (fls == NULL) {
    fflush(fls);
    pclose(fls);
    fprintf(stderr, "Error in reading contents of directory: %s\n", cdir);
    exit(EXIT_FAILURE);
  }

/* Read the values in fls stream. */
  while (((c = getc(fls)) != EOF)) {
    if (c != '\n') {
      line[nchar++] = c;
    } else {
      line[nchar] = '\0';
      nchar = 0;
/* Note that the first line in the total line is not needed here. */
      if (count == 0) {
        printf("\nDirectory: %s\n", cdir);
        printf("Protection   Owner   Group  Size   Created ");
        printf("   Filename\n");
        printf("                          (bytes) (day/time)\n");
        count++;
      }
      else {
        if ((strncmp(line, "total", 5)) != 0) printf("%s\n", line);
        digcnt = 0;
        for (i = 0; line[i] != '\0'; i++) {
          if (i >= 31 && i <= 40) {
            if (isdigit(line[i])) size[digcnt++] = line[i];
          }
        }
        if (digcnt > 0) {
          szfile = szfile + atol(size);
          count++;
          for (i = 0; i < STRMAX; i++) size[i] = '\0';  /* Flush last value */
        }
      }
    }
  }
  fflush(fls);
  pclose(fls);

  szvms = (long int) ((double)szfile/512. + 0.5);
  strcpy(funit, "Bytes");
  if (szfile > 1000l) {
    fscale = 1000.;
    strcpy(funit, "KiloBytes");
  }
  if (szfile > 1000000l) {
    fscale = 1.e6;
    strcpy(funit, "MegaBytes");
  }
  if (szfile > 1000000000l) {
    fscale = 1.e9;
    strcpy(funit, "GigaBytes");
  }

  printf("\nTotal of %d files, at %.2f %s, or %ld (512-byte, VMS) blocks.\n\n", 
     count-1, (double)szfile/fscale, funit, szvms);

  exit(EXIT_SUCCESS);
}