Page History

#include <ctype.h>
#include <stdbool.h>
#include <stdlib.h>
#include <string.h>
#include <stdio.h>
 
static bool isReservedName(const char *path) {
  /* This list of reserved names comes from MSDN */
  static const char *reserved[] = { 
    "nul", "con", "prn", "aux", "com1", "com2", "com3",
    "com4", "com5", "com6", "com7", "com8", "com9",
    "lpt1", "lpt2", "lpt3", "lpt4", "lpt5", "lpt6",
    "lpt7", "lpt8", "lpt9" 
  };
  char *lower;
  char *temp;
  bool ret = false;
  
  /*
   * First, check to see if this is a device namespace, which
   * always starts with \\.\, sincebecause device namespaces are not
   * legal file paths.
   */
  temp = strstr(path, "\\\\.\\");
  if (temp == path) {
    return true;
  }
 
  /*
   * Because Windows uses a case-insensitive file system, operate
   * on a lowercase version of the given filename. Note: this
   * ignores globalization issues and assumes ASCII
   * characters.
   */
  lower = (char *)malloc(strlen(path) + 1);
  if (!lower) {
    return false;
  }
  
  temp = lower;
  while (*path) {
    *lower++ = tolower(*path++);
  }
  lower = temp;
 
  /* Compare against the list of ancient reserved names */
  for (size_t i = 0; !ret &&
       i < sizeof(reserved) / sizeof(*reserved); ++i) {    
    if (0 == strcmp(lower, reserved[i])) {
      ret = true;
    }
  }
 
  free(lower);
  return ret;
}