quakeforge/libs/util/dirent.c

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2001-05-08 20:57:07 +00:00
/*
* dirent.c
*
* Derived from DIRLIB.C by Matt J. Weinstein
* This note appears in the DIRLIB.H
* DIRLIB.H by M. J. Weinstein Released to public domain 1-Jan-89
*
* Updated by Jeremy Bettis <jeremy@hksys.com>
* Significantly revised and rewinddir, seekdir and telldir added by Colin
* Peters <colin@fu.is.saga-u.ac.jp>
*
* $Id$
*
*/
#include <stdlib.h>
#include <errno.h>
#include <string.h>
#include <io.h>
#include <direct.h>
#include <sys/stat.h>
#include <dirent.h>
#define SUFFIX "*"
#define SLASH "\\"
#ifndef S_ISDIR
#define S_ISDIR(m) ((m & S_IFMT) == S_IFDIR) /* is a directory */
#endif S_ISDIR
/*
* opendir
*
* Returns a pointer to a DIR structure appropriately filled in to begin
* searching a directory.
*/
DIR *
opendir (const char *szPath)
{
DIR *nd;
struct _stat statDir;
errno = 0;
if (!szPath) {
errno = EFAULT;
return (DIR *) 0;
}
if (szPath[0] == '\0') {
errno = ENOTDIR;
return (DIR *) 0;
}
/* Attempt to determine if the given path really is a directory. */
if (_stat (szPath, &statDir)) {
/* Error, stat should have set an error value. */
return (DIR *) 0;
}
if (!S_ISDIR (statDir.st_mode)) {
/* Error, stat reports not a directory. */
errno = ENOTDIR;
return (DIR *) 0;
}
/* Allocate enough space to store DIR structure and the complete *
directory path given. */
nd = (DIR *) calloc (1, sizeof (DIR) + strlen (szPath) + strlen (SLASH) +
strlen (SUFFIX));
if (!nd) {
/* Error, out of memory. */
errno = ENOMEM;
return (DIR *) 0;
}
/* Create the search expression. */
strcpy (nd->dd_name, szPath);
/* Add on a slash if the path does not end with one. */
if (nd->dd_name[0] != '\0' &&
nd->dd_name[strlen (nd->dd_name) - 1] != '/' &&
nd->dd_name[strlen (nd->dd_name) - 1] != '\\') {
strcat (nd->dd_name, SLASH);
}
/* Add on the search pattern */
strcat (nd->dd_name, SUFFIX);
/* Initialize handle to -1 so that a premature closedir doesn't try * to
call _findclose on it. */
nd->dd_handle = -1;
/* Initialize the status. */
nd->dd_stat = 0;
/* Initialize the dirent structure. ino and reclen are invalid under *
Win32, and name simply points at the appropriate part of the *
findfirst_t structure. */
nd->dd_dir.d_ino = 0;
nd->dd_dir.d_reclen = 0;
nd->dd_dir.d_namlen = 0;
nd->dd_dir.d_name = nd->dd_dta.name;
return nd;
}
/*
* readdir
*
* Return a pointer to a dirent structure filled with the information on the
* next entry in the directory.
*/
struct dirent *
readdir (DIR * dirp)
{
errno = 0;
/* Check for valid DIR struct. */
if (!dirp) {
errno = EFAULT;
return (struct dirent *) 0;
}
if (dirp->dd_dir.d_name != dirp->dd_dta.name) {
/* The structure does not seem to be set up correctly. */
errno = EINVAL;
return (struct dirent *) 0;
}
if (dirp->dd_stat < 0) {
/* We have already returned all files in the directory * (or the
structure has an invalid dd_stat). */
return (struct dirent *) 0;
} else if (dirp->dd_stat == 0) {
/* We haven't started the search yet. */
/* Start the search */
dirp->dd_handle = _findfirst (dirp->dd_name, &(dirp->dd_dta));
if (dirp->dd_handle == -1) {
/* Whoops! Seems there are no files in that * directory. */
dirp->dd_stat = -1;
} else {
dirp->dd_stat = 1;
}
} else {
/* Get the next search entry. */
if (_findnext (dirp->dd_handle, &(dirp->dd_dta))) {
/* We are off the end or otherwise error. */
_findclose (dirp->dd_handle);
dirp->dd_handle = -1;
dirp->dd_stat = -1;
} else {
/* Update the status to indicate the correct * number. */
dirp->dd_stat++;
}
}
if (dirp->dd_stat > 0) {
/* Successfully got an entry. Everything about the file is * already
appropriately filled in except the length of the * file name. */
dirp->dd_dir.d_namlen = strlen (dirp->dd_dir.d_name);
return &dirp->dd_dir;
}
return (struct dirent *) 0;
}
/*
* closedir
*
* Frees up resources allocated by opendir.
*/
int
closedir (DIR * dirp)
{
int rc;
errno = 0;
rc = 0;
if (!dirp) {
errno = EFAULT;
return -1;
}
if (dirp->dd_handle != -1) {
rc = _findclose (dirp->dd_handle);
}
/* Delete the dir structure. */
free (dirp);
return rc;
}
/*
* rewinddir
*
* Return to the beginning of the directory "stream". We simply call findclose
* and then reset things like an opendir.
*/
void
rewinddir (DIR * dirp)
{
errno = 0;
if (!dirp) {
errno = EFAULT;
return;
}
if (dirp->dd_handle != -1) {
_findclose (dirp->dd_handle);
}
dirp->dd_handle = -1;
dirp->dd_stat = 0;
}
/*
* telldir
*
* Returns the "position" in the "directory stream" which can be used with
* seekdir to go back to an old entry. We simply return the value in stat.
*/
long
telldir (DIR * dirp)
{
errno = 0;
if (!dirp) {
errno = EFAULT;
return -1;
}
return dirp->dd_stat;
}
/*
* seekdir
*
* Seek to an entry previously returned by telldir. We rewind the directory
* and call readdir repeatedly until either dd_stat is the position number
* or -1 (off the end). This is not perfect, in that the directory may
* have changed while we weren't looking. But that is probably the case with
* any such system.
*/
void
seekdir (DIR * dirp, long lPos)
{
errno = 0;
if (!dirp) {
errno = EFAULT;
return;
}
if (lPos < -1) {
/* Seeking to an invalid position. */
errno = EINVAL;
return;
} else if (lPos == -1) {
/* Seek past end. */
if (dirp->dd_handle != -1) {
_findclose (dirp->dd_handle);
}
dirp->dd_handle = -1;
dirp->dd_stat = -1;
} else {
/* Rewind and read forward to the appropriate index. */
rewinddir (dirp);
while ((dirp->dd_stat < lPos) && readdir (dirp));
}
}