/* Last edited on 2024-12-25 10:18:13 by stolfi */ 

#include <sys/types.h>
#include <sys/stat.h>
#include <dirent.h>
#include <string.h>
#include <stdio.h>
#include <unistd.h>
#include <stdlib.h>

#include <enum-dir_doc.h>

/* Local prototypes: */

int main(int argc, char **argv);
void error (char *msg);

int main(int argc, char **argv)
{
  int k;
  int listFiles = 1, listDirs = 1, listLinks = 1, listErrors = 1, listOthers = 1;
  int followLinks = 0, showType = 0, partialList = 0;
    
  /* Parse options: */
  for (k=1; k < argc; k++)
    {
      char *op = argv[k];
      if ((*op) == '\0')
        { }
      else if (strcmp(op, "-type") == 0)
        { if (partialList) { error("enum-dir: duplicate option"); }
          partialList = 1;
          k++; 
          /* Parse type codes: */
          listFiles = 0;
          listDirs = 0;
          listLinks = 0;
          listErrors = 0; 
          listOthers = 0;
          if (k >= argc) { error("enum-dir: missing type codes"); }
          { char *tset = argv[k];
            while ((*tset) != '\0')
              { if ((*tset) == 'f') listFiles = 1; else 
                if ((*tset) == 'd') listDirs = 1; else 
                if ((*tset) == 'l') listLinks = 1; else 
                if ((*tset) == 'e') listErrors = 1; else 
                if ((*tset) == 'o') listOthers = 1; else 
                  { error("enum-dir: bad entry type"); }
                tset++;
              }
          }
        }
      else if (strcmp(op, "-showType") == 0)
        { if (showType) { error("enum-dir: duplicate option"); }
          showType = 1; 
        }
      else if (strcmp(op, "-followLinks") == 0)
        { if (followLinks) { error("enum-dir: duplicate option"); }
          followLinks = 1;
        }
      else if ((*op) == '-')
        { error("enum-dir: bad option"); }
      else
        { char *dir_path = argv[k];
          int res;
          if (k != argc-1) error("enum-dir: too many arguments");
          if ((*dir_path) == '\0') error("enum-dir: pathname is empty");
          res = chdir(dir_path);
          if (res) { perror("enum-dir"); abort(); }
        }
    }
    
  /* Enumerate directory: */
  {
    struct stat edata;
    struct dirent *ep;
    DIR *dirp = opendir(".");
    if (dirp == NULL) 
      { perror("enum-dir"); abort(); }
    for (ep = readdir(dirp); ep != NULL; ep = readdir(dirp))
      { char etype = '?';
        int printIt = 0;
        if (partialList || showType)
          { /* Must determine entry type */
            if ((strcmp(ep->d_name, ".") == 0) || (strcmp(ep->d_name, "..") == 0))
              { etype = 'o'; printIt = listOthers; }
            else
              { int res;
                if (followLinks)
                  { res = stat(ep->d_name, &edata); }
                else
                  { res = lstat(ep->d_name, &edata); }
                if (res)
                  { etype = 'e'; printIt = listErrors; }
                else if (S_ISDIR(edata.st_mode))
                  { etype = 'd'; printIt = listDirs; }
                else if (S_ISREG(edata.st_mode))
                  { etype = 'f'; printIt = listFiles; }
                else if (S_ISLNK(edata.st_mode))
                  { etype = 'l'; printIt = listLinks; }
                else 
                  { etype = 'o'; printIt = listOthers; }
              }
          }
        else
          { etype = '?'; printIt = 1; }
        
        if (printIt)
          { if (showType) { putc(etype, stdout); putc(' ', stdout); }
            printf("%s\n", ep->d_name);
          }
      }
    closedir (dirp);
    return (0);
  }
}

void error (char *msg)
  { fprintf (stderr, "%s\n", msg);
    exit(1);
  }