ref: 5b3b1bbab6c49148b9309d0a9de0ef33e1a63513
dir: /win32/win_opendir.c/
// // 03/10/2006 James Haley // // For this module only: // This code is public domain. No change sufficient enough to constitute a // significant or original work has been made, and thus it remains as such. // // // DESCRIPTION: // // Implementation of POSIX opendir for Visual C++. // Derived from the MinGW C Library Extensions Source (released to the // public domain). As with other Win32 modules, don't include most DOOM // headers into this or conflicts will occur. // // Original Header: // // * dirent.c // * This file has no copyright assigned and is placed in the Public Domain. // * This file is a part of the mingw-runtime package. // * No warranty is given; refer to the file DISCLAIMER within the package. // * // * 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 <[email protected]> // * Significantly revised and rewinddir, seekdir and telldir added by Colin // * Peters <[email protected]> // #ifndef _MSC_VER #error i_opndir.c is for Microsoft Visual C++ only #endif #include <stdlib.h> #include <errno.h> #include <string.h> #define WIN32_LEAN_AND_MEAN #include <windows.h> /* for GetFileAttributes */ #include <tchar.h> #define SUFFIX _T("*") #define SLASH _T("\\") #include "win_opendir.h" // // opendir // // Returns a pointer to a DIR structure appropriately filled in to begin // searching a directory. // DIR *opendir(const _TCHAR *szPath) { DIR *nd; unsigned int rc; _TCHAR szFullPath[MAX_PATH]; errno = 0; if(!szPath) { errno = EFAULT; return (DIR *)0; } if(szPath[0] == _T('\0')) { errno = ENOTDIR; return (DIR *)0; } /* Attempt to determine if the given path really is a directory. */ rc = GetFileAttributes(szPath); if(rc == (unsigned int)-1) { /* call GetLastError for more error info */ errno = ENOENT; return (DIR *)0; } if(!(rc & FILE_ATTRIBUTE_DIRECTORY)) { /* Error, entry exists but not a directory. */ errno = ENOTDIR; return (DIR *)0; } /* Make an absolute pathname. */ _tfullpath(szFullPath, szPath, MAX_PATH); /* Allocate enough space to store DIR structure and the complete * directory path given. */ nd = (DIR *)(malloc(sizeof(DIR) + (_tcslen(szFullPath) + _tcslen(SLASH) + _tcslen(SUFFIX) + 1) * sizeof(_TCHAR))); if(!nd) { /* Error, out of memory. */ errno = ENOMEM; return (DIR *)0; } /* Create the search expression. */ _tcscpy(nd->dd_name, szFullPath); /* Add on a slash if the path does not end with one. */ if(nd->dd_name[0] != _T('\0') && _tcsrchr(nd->dd_name, _T('/')) != nd->dd_name + _tcslen(nd->dd_name) - 1 && _tcsrchr(nd->dd_name, _T('\\')) != nd->dd_name + _tcslen(nd->dd_name) - 1) { _tcscat(nd->dd_name, SLASH); } /* Add on the search pattern */ _tcscat(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; memset(nd->dd_dir.d_name, 0, FILENAME_MAX); 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_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 = _tfindfirst(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(_tfindnext(dirp->dd_handle, &(dirp->dd_dta))) { /* We are off the end or otherwise error. _findnext sets errno to ENOENT if no more file Undo this. */ DWORD winerr = GetLastError(); if(winerr == ERROR_NO_MORE_FILES) errno = 0; _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 = _tcslen(dirp->dd_dta.name); _tcscpy(dirp->dd_dir.d_name, dirp->dd_dta.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)) ; /* do-nothing loop */ } } // EOF