crypto/LPdir_unix.c

   1 /*
   2  * $LP: LPlib/source/LPdir_unix.c,v 1.11 2004/09/23 22:07:22 _cvs_levitte Exp
   3  * $
   4  */
   5 /*
   6  * Copyright (c) 2004, Richard Levitte <richard@levitte.org>
   7  * All rights reserved.
   8  *
   9  * Redistribution and use in source and binary forms, with or without
  10  * modification, are permitted provided that the following conditions
  11  * are met:
  12  * 1. Redistributions of source code must retain the above copyright
  13  *    notice, this list of conditions and the following disclaimer.
  14  * 2. Redistributions in binary form must reproduce the above copyright
  15  *    notice, this list of conditions and the following disclaimer in the
  16  *    documentation and/or other materials provided with the distribution.
  17  *
  18  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  19  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  20  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  21  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  22  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  23  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  24  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  25  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  26  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  27  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  28  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  29  */
  30
  31 #include <stddef.h>
  32 #include <stdlib.h>
  33 #include <limits.h>
  34 #include <string.h>
  35 #include <sys/types.h>
  36 #include <dirent.h>
  37 #include <errno.h>
  38 #ifndef LPDIR_H
  39 # include "LPdir.h"
  40 #endif
  41
  42 /*
  43  * The POSIXly macro for the maximum number of characters in a file path is
  44  * NAME_MAX.  However, some operating systems use PATH_MAX instead.
  45  * Therefore, it seems natural to first check for PATH_MAX and use that, and
  46  * if it doesn't exist, use NAME_MAX.
  47  */
  48 #if defined(PATH_MAX)
  49 # define LP_ENTRY_SIZE PATH_MAX
  50 #elif defined(NAME_MAX)
  51 # define LP_ENTRY_SIZE NAME_MAX
  52 #endif
  53
  54 /*
  55  * Of course, there's the possibility that neither PATH_MAX nor NAME_MAX
  56  * exist.  It's also possible that NAME_MAX exists but is define to a very
  57  * small value (HP-UX offers 14), so we need to check if we got a result, and
  58  * if it meets a minimum standard, and create or change it if not.
  59  */
  60 #if !defined(LP_ENTRY_SIZE) || LP_ENTRY_SIZE<255
  61 # undef LP_ENTRY_SIZE
  62 # define LP_ENTRY_SIZE 255
  63 #endif
  64
  65 struct LP_dir_context_st {
  66     DIR *dir;
  67     char entry_name[LP_ENTRY_SIZE + 1];
  68 };
  69
  70 const char *LP_find_file(LP_DIR_CTX **ctx, const char *directory)
  71 {
  72     struct dirent *direntry = NULL;
  73
  74     if (ctx == NULL || directory == NULL) {
  75         errno = EINVAL;
  76         return 0;
  77     }
  78
  79     errno = 0;
  80     if (*ctx == NULL) {
  81         *ctx = (LP_DIR_CTX *)malloc(sizeof(LP_DIR_CTX));
  82         if (*ctx == NULL) {
  83             errno = ENOMEM;
  84             return 0;
  85         }
  86         memset(*ctx, '\0', sizeof(LP_DIR_CTX));
  87
  88         (*ctx)->dir = opendir(directory);
  89         if ((*ctx)->dir == NULL) {
  90             int save_errno = errno; /* Probably not needed, but I'm paranoid */
  91             free(*ctx);
  92             *ctx = NULL;
  93             errno = save_errno;
  94             return 0;
  95         }
  96     }
  97
  98     direntry = readdir((*ctx)->dir);
  99     if (direntry == NULL) {
 100         return 0;
 101     }
 102
 103     strncpy((*ctx)->entry_name, direntry->d_name,
 104             sizeof((*ctx)->entry_name) - 1);
 105     (*ctx)->entry_name[sizeof((*ctx)->entry_name) - 1] = '\0';
 106     return (*ctx)->entry_name;
 107 }
 108
 109 int LP_find_file_end(LP_DIR_CTX **ctx)
 110 {
 111     if (ctx != NULL && *ctx != NULL) {
 112         int ret = closedir((*ctx)->dir);
 113
 114         free(*ctx);
 115         switch (ret) {
 116         case 0:
 117             return 1;
 118         case -1:
 119             return 0;
 120         default:
 121             break;
 122         }
 123     }
 124     errno = EINVAL;
 125     return 0;
 126 }