/* newdir.c create directory and change to it */
#include <sys/types.h>
#include <sys/stat.h>
#include <stdio.h>
#include <dirent.h>
#include <string.h>
#include <stdlib.h>
#include <unistd.h>

int main(int argc, char ** argv) {
   struct stat statbuffer; /*file stat*/
   struct dirent * direntry; /* directory entry for readdir */
   char * p;
   DIR * dir; /* stream handle for directory -> opendir */

   if (argc != 2) {
     fprintf(stderr, "Usage: %s newdirectory\n", argv[0]);
     exit(1);
   }

   if (stat(".", &statbuffer) < 0) {
         perror("stat error with '.'");
         exit(2);
   }
   if ( (statbuffer.st_mode & S_IFMT) != S_IFDIR) {
         perror(". no directory?");
         exit(3);
   }

   /* open directory and scan for argv[1]:*/
   dir = opendir(".");
   while( (direntry = readdir(dir))!=NULL) {
      if (strcmp(direntry->d_name, argv[1]) == 0) {
	 fprintf(stderr,"%s already exists\n", argv[1]);
	 exit(4);
      }

   }

   /* make newdir: */
   if ( (p = (char *) malloc(256)) == NULL) {
      perror("mcalloc");
      exit(5);
   }
   if (sprintf(p,"./%s",argv[1]) <= 0) {
      perror("sprintf");
      exit(6);
   };
   if (mkdir(p,0777) < 0) {
     perror("mkdir");
     exit(7);
   }

   /* change to this dir */

   if ( chdir(p) < 0 ) {
      perror("chdir");
      exit(8);
   }
   printf("now working directory: "); 
   fflush(stdout);
   system("pwd");
   exit(0);
}