php-src/TSRM/tsrm_virtual_cwd.c

/*
   +----------------------------------------------------------------------+
   | PHP Version 5                                                        |
   +----------------------------------------------------------------------+
   | Copyright (c) 1997-2009 The PHP Group                                |
   +----------------------------------------------------------------------+
   | This source file is subject to version 3.01 of the PHP license,      |
   | that is bundled with this package in the file LICENSE, and is        |
   | available through the world-wide-web at the following url:           |
   | http://www.php.net/license/3_01.txt                                  |
   | If you did not receive a copy of the PHP license and are unable to   |
   | obtain it through the world-wide-web, please send a note to          |
   | license@php.net so we can mail you a copy immediately.               |
   +----------------------------------------------------------------------+
   | Authors: Andi Gutmans <andi@zend.com>                                |
   |          Sascha Schumann <sascha@schumann.cx>                        |
   +----------------------------------------------------------------------+
*/

/* $Id$ */

#include <sys/types.h>
#include <sys/stat.h>
#include <string.h>
#include <stdio.h>
#include <limits.h>
#include <errno.h>
#include <stdlib.h>
#include <fcntl.h>
#include <time.h>

#include "tsrm_virtual_cwd.h"
#include "tsrm_strtok_r.h"

#ifdef TSRM_WIN32
#include <io.h>
#include "tsrm_win32.h"
# ifndef IO_REPARSE_TAG_SYMLINK
#  define IO_REPARSE_TAG_SYMLINK 0xA000000C
# endif
#endif

#ifdef NETWARE
#include <fsio.h>
#endif

#ifndef HAVE_REALPATH
#define realpath(x,y) strcpy(y,x)
#endif

#define VIRTUAL_CWD_DEBUG 0

#include "TSRM.h"

/* Only need mutex for popen() in Windows and NetWare because it doesn't chdir() on UNIX */
#if (defined(TSRM_WIN32) || defined(NETWARE)) && defined(ZTS)
MUTEX_T cwd_mutex;
#endif

#ifdef ZTS
ts_rsrc_id cwd_globals_id;
#else
virtual_cwd_globals cwd_globals;
#endif

cwd_state main_cwd_state; /* True global */

#ifndef TSRM_WIN32
#include <unistd.h>
#else
#include <direct.h>
#endif

#ifndef S_ISDIR
#define S_ISDIR(mode) ((mode) & _S_IFDIR)
#endif

#ifndef S_ISREG
#define S_ISREG(mode) ((mode) & _S_IFREG)
#endif

#ifdef TSRM_WIN32
#include <tchar.h>
#define tsrm_strtok_r(a,b,c) _tcstok((a),(b))
#define TOKENIZER_STRING "/\\"
	
static int php_check_dots(const char *element, int n) 
{
	while (n-- > 0) if (element[n] != '.') break;

	return (n != -1);
}
	
#define IS_DIRECTORY_UP(element, len) \
	(len >= 2 && !php_check_dots(element, len))

#define IS_DIRECTORY_CURRENT(element, len) \
	(len == 1 && element[0] == '.')

#elif defined(NETWARE)
/* NetWare has strtok() (in LibC) and allows both slashes in paths, like Windows --
   but rest of the stuff is like Unix */
/* strtok() call in LibC is abending when used in a different address space -- hence using
   PHP's version itself for now */
/*#define tsrm_strtok_r(a,b,c) strtok((a),(b))*/
#define TOKENIZER_STRING "/\\"

#else
#define TOKENIZER_STRING "/"
#endif


/* default macros */

#ifndef IS_DIRECTORY_UP
#define IS_DIRECTORY_UP(element, len) \
	(len == 2 && element[0] == '.' && element[1] == '.')
#endif

#ifndef IS_DIRECTORY_CURRENT
#define IS_DIRECTORY_CURRENT(element, len) \
	(len == 1 && element[0] == '.')
#endif

/* define this to check semantics */
#define IS_DIR_OK(s) (1)
	
#ifndef IS_DIR_OK
#define IS_DIR_OK(state) (php_is_dir_ok(state) == 0)
#endif


#define CWD_STATE_COPY(d, s)				\
	(d)->cwd_length = (s)->cwd_length;		\
	(d)->cwd = (char *) malloc((s)->cwd_length+1);	\
	memcpy((d)->cwd, (s)->cwd, (s)->cwd_length+1);

#define CWD_STATE_FREE(s)			\
	free((s)->cwd);
	
#ifdef TSRM_WIN32

#ifdef CTL_CODE
#undef CTL_CODE
#endif
#define CTL_CODE(DeviceType,Function,Method,Access) (((DeviceType) << 16) | ((Access) << 14) | ((Function) << 2) | (Method))
#define FILE_DEVICE_FILE_SYSTEM 0x00000009
#define METHOD_BUFFERED		0
#define FILE_ANY_ACCESS 	0
#define FSCTL_GET_REPARSE_POINT CTL_CODE(FILE_DEVICE_FILE_SYSTEM, 42, METHOD_BUFFERED, FILE_ANY_ACCESS)
#define MAXIMUM_REPARSE_DATA_BUFFER_SIZE  ( 16 * 1024 )

typedef struct {
	unsigned long  ReparseTag;
	unsigned short ReparseDataLength;
	unsigned short Reserved;
	union {
		struct {
			unsigned short SubstituteNameOffset;
			unsigned short SubstituteNameLength;
			unsigned short PrintNameOffset;
			unsigned short PrintNameLength;
			unsigned long  Flags;
			wchar_t        ReparseTarget[1];
		} SymbolicLinkReparseBuffer;
		struct {
			unsigned short SubstituteNameOffset;
			unsigned short SubstituteNameLength;
			unsigned short PrintNameOffset;
			unsigned short PrintNameLength;
			wchar_t        ReparseTarget[1];
		} MountPointReparseBuffer;
		struct {
			unsigned char  ReparseTarget[1];
		} GenericReparseBuffer;
	};
} REPARSE_DATA_BUFFER;

#define SECS_BETWEEN_EPOCHS (__int64)11644473600
#define SECS_TO_100NS (__int64)10000000
static inline time_t FileTimeToUnixTime(const FILETIME FileTime)
{
	__int64 UnixTime;
	long *nsec = NULL;
	SYSTEMTIME SystemTime;
	FileTimeToSystemTime(&FileTime, &SystemTime);

	UnixTime = ((__int64)FileTime.dwHighDateTime << 32) +
	FileTime.dwLowDateTime;

	UnixTime -= (SECS_BETWEEN_EPOCHS * SECS_TO_100NS);

	if (nsec) {
		*nsec = (UnixTime % SECS_TO_100NS) * (__int64)100;
	}

	UnixTime /= SECS_TO_100NS; /* now convert to seconds */

	if ((time_t)UnixTime != UnixTime) {
		UnixTime = 0;
	}
	return (time_t)UnixTime;
}

CWD_API int php_sys_stat(const char *path, struct stat *buf) /* {{{ */
{
	WIN32_FILE_ATTRIBUTE_DATA data;
	__int64 t;

	if (!GetFileAttributesEx(path, GetFileExInfoStandard, &data)) {
		return stat(path, buf);
	}

	if (path[1] == ':') {
		if (path[0] >= 'A' && path[0] <= 'Z') {
			buf->st_dev = buf->st_rdev = path[0] - 'A';
		} else {
			buf->st_dev = buf->st_rdev = path[0] - 'a';
		}
	} else {
		char  cur_path[MAXPATHLEN+1];
		DWORD len = sizeof(cur_path);
		char *tmp = cur_path;

		while(1) {
			DWORD r = GetCurrentDirectory(len, tmp);
			if (r < len) {
				if (tmp[1] == ':') {
					if (path[0] >= 'A' && path[0] <= 'Z') {
						buf->st_dev = buf->st_rdev = path[0] - 'A';
					} else {
						buf->st_dev = buf->st_rdev = path[0] - 'a';
					}
				} else {
					buf->st_dev = buf->st_rdev = -1;
				}
				break;
			} else if (!r) {
				buf->st_dev = buf->st_rdev = -1;
				break;
			} else {
				len = r+1;
				tmp = (char*)malloc(len);
			}
		}
		if (tmp != cur_path) {
			free(tmp);
		}		    	
	}
	buf->st_uid = buf->st_gid = buf->st_ino = 0;
	buf->st_mode = (data.dwFileAttributes & FILE_ATTRIBUTE_DIRECTORY) ? (S_IFDIR|S_IEXEC|(S_IEXEC>>3)|(S_IEXEC>>6)) : S_IFREG;
	buf->st_mode |= (data.dwFileAttributes & FILE_ATTRIBUTE_READONLY) ? (S_IREAD|(S_IREAD>>3)|(S_IREAD>>6)) : (S_IREAD|(S_IREAD>>3)|(S_IREAD>>6)|S_IWRITE|(S_IWRITE>>3)|(S_IWRITE>>6));
	if ((data.dwFileAttributes & FILE_ATTRIBUTE_DIRECTORY) == 0) {
		int len = strlen(path);

		if (path[len-4] == '.') {
			if (_memicmp(path+len-3, "exe", 3) == 0 ||
			    _memicmp(path+len-3, "com", 3) == 0 ||
			    _memicmp(path+len-3, "bat", 3) == 0 ||
			    _memicmp(path+len-3, "cmd", 3) == 0) {
				buf->st_mode  |= (S_IEXEC|(S_IEXEC>>3)|(S_IEXEC>>6));
			}
		}
	}

	buf->st_nlink = 1;
	t = data.nFileSizeHigh;
	t = t << 32;
	t |= data.nFileSizeLow;
	buf->st_size = t;
	buf->st_atime = FileTimeToUnixTime(data.ftLastAccessTime);
	buf->st_ctime = FileTimeToUnixTime(data.ftCreationTime);
	buf->st_mtime = FileTimeToUnixTime(data.ftLastWriteTime);
	if (buf->st_mtime != buf->st_atime) {
		buf->st_atime = buf->st_mtime;
	}
	return 0;
}
/* }}} */
#endif

static int php_is_dir_ok(const cwd_state *state)  /* {{{ */
{
	struct stat buf;

	if (php_sys_stat(state->cwd, &buf) == 0 && S_ISDIR(buf.st_mode))
		return (0);

	return (1);
}
/* }}} */

static int php_is_file_ok(const cwd_state *state)  /* {{{ */
{
	struct stat buf;

	if (php_sys_stat(state->cwd, &buf) == 0 && S_ISREG(buf.st_mode))
		return (0);

	return (1);
}
/* }}} */

static void cwd_globals_ctor(virtual_cwd_globals *cwd_globals TSRMLS_DC) /* {{{ */
{
	CWD_STATE_COPY(&cwd_globals->cwd, &main_cwd_state);
	cwd_globals->realpath_cache_size = 0;
	cwd_globals->realpath_cache_size_limit = REALPATH_CACHE_SIZE;
	cwd_globals->realpath_cache_ttl = REALPATH_CACHE_TTL;
	memset(cwd_globals->realpath_cache, 0, sizeof(cwd_globals->realpath_cache));
}
/* }}} */

static void cwd_globals_dtor(virtual_cwd_globals *cwd_globals TSRMLS_DC) /* {{{ */
{
	CWD_STATE_FREE(&cwd_globals->cwd);
	realpath_cache_clean(TSRMLS_C);
}
/* }}} */

CWD_API void virtual_cwd_startup(void) /* {{{ */
{
	char cwd[MAXPATHLEN];
	char *result;

#ifdef NETWARE
	result = getcwdpath(cwd, NULL, 1);
	if(result)
	{
		char *c=cwd;
		while(c = strchr(c, '\\'))
		{
			*c='/';
			++c;
		}
	}
#else
	result = getcwd(cwd, sizeof(cwd));	
#endif
	if (!result) {
		cwd[0] = '\0';
	}

	main_cwd_state.cwd_length = strlen(cwd);
#ifdef TSRM_WIN32
	if (main_cwd_state.cwd_length >= 2 && cwd[1] == ':') {
		cwd[0] = toupper(cwd[0]);
	}
#endif
	main_cwd_state.cwd = strdup(cwd);

#ifdef ZTS
	ts_allocate_id(&cwd_globals_id, sizeof(virtual_cwd_globals), (ts_allocate_ctor) cwd_globals_ctor, (ts_allocate_dtor) cwd_globals_dtor);
#else
	cwd_globals_ctor(&cwd_globals TSRMLS_CC);
#endif

#if (defined(TSRM_WIN32) || defined(NETWARE)) && defined(ZTS)
	cwd_mutex = tsrm_mutex_alloc();
#endif
}
/* }}} */

CWD_API void virtual_cwd_shutdown(void) /* {{{ */
{
#ifndef ZTS
	cwd_globals_dtor(&cwd_globals TSRMLS_CC);
#endif
#if (defined(TSRM_WIN32) || defined(NETWARE)) && defined(ZTS)
	tsrm_mutex_free(cwd_mutex);
#endif

	free(main_cwd_state.cwd); /* Don't use CWD_STATE_FREE because the non global states will probably use emalloc()/efree() */
}
/* }}} */

CWD_API char *virtual_getcwd_ex(size_t *length TSRMLS_DC) /* {{{ */
{
	cwd_state *state;

	state = &CWDG(cwd);

	if (state->cwd_length == 0) {
		char *retval;

		*length = 1;
		retval = (char *) malloc(2);
		retval[0] = DEFAULT_SLASH;
		retval[1] = '\0';	
		return retval;
	}

#ifdef TSRM_WIN32
	/* If we have something like C: */
	if (state->cwd_length == 2 && state->cwd[state->cwd_length-1] == ':') {
		char *retval;

		*length = state->cwd_length+1;
		retval = (char *) malloc(*length+1);
		memcpy(retval, state->cwd, *length);
		retval[0] = toupper(retval[0]);
		retval[*length-1] = DEFAULT_SLASH;
		retval[*length] = '\0';
		return retval;
	}
#endif
	*length = state->cwd_length;
	return strdup(state->cwd);
}
/* }}} */

/* Same semantics as UNIX getcwd() */
CWD_API char *virtual_getcwd(char *buf, size_t size TSRMLS_DC) /* {{{ */
{
	size_t length;
	char *cwd;

	cwd = virtual_getcwd_ex(&length TSRMLS_CC);

	if (buf == NULL) {
		return cwd;
	}
	if (length > size-1) {
		free(cwd);
		errno = ERANGE; /* Is this OK? */
		return NULL;
	}
	memcpy(buf, cwd, length+1);
	free(cwd);
	return buf;
}
/* }}} */

static inline unsigned long realpath_cache_key(const char *path, int path_len) /* {{{ */
{
	register unsigned long h;
	const char *e = path + path_len;

	for (h = 2166136261U; path < e;) {
		h *= 16777619;
		h ^= *path++;
	}

	return h;
}
/* }}} */

CWD_API void realpath_cache_clean(TSRMLS_D) /* {{{ */
{
	int i;

	for (i = 0; i < sizeof(CWDG(realpath_cache))/sizeof(CWDG(realpath_cache)[0]); i++) {
		realpath_cache_bucket *p = CWDG(realpath_cache)[i];
		while (p != NULL) {
			realpath_cache_bucket *r = p;
			p = p->next;
			free(r);
		}
		CWDG(realpath_cache)[i] = NULL;
	}
	CWDG(realpath_cache_size) = 0;
}
/* }}} */

CWD_API void realpath_cache_del(const char *path, int path_len TSRMLS_DC) /* {{{ */
{
	unsigned long key = realpath_cache_key(path, path_len);
	unsigned long n = key % (sizeof(CWDG(realpath_cache)) / sizeof(CWDG(realpath_cache)[0]));
	realpath_cache_bucket **bucket = &CWDG(realpath_cache)[n];

	while (*bucket != NULL) {
		if (key == (*bucket)->key && path_len == (*bucket)->path_len &&
		           memcmp(path, (*bucket)->path, path_len) == 0) {
			realpath_cache_bucket *r = *bucket;
			*bucket = (*bucket)->next;
			CWDG(realpath_cache_size) -= sizeof(realpath_cache_bucket) + r->path_len + 1 + r->realpath_len + 1;
			free(r);
			return;
		} else {
			bucket = &(*bucket)->next;
		}
	}
}
/* }}} */

static inline void realpath_cache_add(const char *path, int path_len, const char *realpath, int realpath_len, int is_dir, time_t t TSRMLS_DC) /* {{{ */
{
	long size = sizeof(realpath_cache_bucket) + path_len + 1;
	int same = 1;
	
	if (realpath_len != path_len ||
	    memcmp(path, realpath, path_len) != 0) {
		size += realpath_len + 1;
		same = 0;
	}

	if (CWDG(realpath_cache_size) + size <= CWDG(realpath_cache_size_limit)) {
		realpath_cache_bucket *bucket = malloc(size);
		unsigned long n;
	
		bucket->key = realpath_cache_key(path, path_len);
		bucket->path = (char*)bucket + sizeof(realpath_cache_bucket);
		memcpy(bucket->path, path, path_len+1);
		bucket->path_len = path_len;
		if (same) {
			bucket->realpath = bucket->path;
		} else {
			bucket->realpath = bucket->path + (path_len + 1);
			memcpy(bucket->realpath, realpath, realpath_len+1);
		}
		bucket->realpath_len = realpath_len;
		bucket->is_dir = is_dir;
#ifdef PHP_WIN32
		bucket->is_rvalid   = 0;
		bucket->is_readable = 0;
		bucket->is_wvalid   = 0;
		bucket->is_writable = 0;
#endif
		bucket->expires = t + CWDG(realpath_cache_ttl);
		n = bucket->key % (sizeof(CWDG(realpath_cache)) / sizeof(CWDG(realpath_cache)[0]));
		bucket->next = CWDG(realpath_cache)[n];
		CWDG(realpath_cache)[n] = bucket;
		CWDG(realpath_cache_size) += size;
	}
}
/* }}} */

static inline realpath_cache_bucket* realpath_cache_find(const char *path, int path_len, time_t t TSRMLS_DC) /* {{{ */
{
	unsigned long key = realpath_cache_key(path, path_len);
	unsigned long n = key % (sizeof(CWDG(realpath_cache)) / sizeof(CWDG(realpath_cache)[0]));
	realpath_cache_bucket **bucket = &CWDG(realpath_cache)[n];

	while (*bucket != NULL) {
		if (CWDG(realpath_cache_ttl) && (*bucket)->expires < t) {
			realpath_cache_bucket *r = *bucket;
			*bucket = (*bucket)->next;
			CWDG(realpath_cache_size) -= sizeof(realpath_cache_bucket) + r->path_len + 1 + r->realpath_len + 1;
			free(r);
		} else if (key == (*bucket)->key && path_len == (*bucket)->path_len &&
		           memcmp(path, (*bucket)->path, path_len) == 0) {
			return *bucket;
		} else {
			bucket = &(*bucket)->next;
		}
	}
	return NULL;
}
/* }}} */

CWD_API realpath_cache_bucket* realpath_cache_lookup(const char *path, int path_len, time_t t TSRMLS_DC) /* {{{ */
{
    return realpath_cache_find(path, path_len, t TSRMLS_CC);
}
/* }}} */

#undef LINK_MAX
#define LINK_MAX 32

static int tsrm_realpath_r(char *path, int start, int len, int *ll, time_t *t, int use_realpath, int is_dir, int *link_is_dir TSRMLS_DC) /* {{{ */
{
	int i, j, save;
	int directory = 0;
#ifdef TSRM_WIN32
	WIN32_FIND_DATA data;
	HANDLE hFind;
#else
	struct stat st;
#endif
	realpath_cache_bucket *bucket;
	char *tmp;
	TSRM_ALLOCA_FLAG(use_heap)
	TSRM_ALLOCA_FLAG(use_heap_large)

	while (1) {
		if (len <= start) {
			return start;
		}

		i = len;
		while (i > start && !IS_SLASH(path[i-1])) {
			i--;
		}

		if (i == len ||
			(i == len - 1 && path[i] == '.')) {
			/* remove double slashes and '.' */
			len = i - 1;
			is_dir = 1;
			continue;
		} else if (i == len - 2 && path[i] == '.' && path[i+1] == '.') {
			/* remove '..' and previous directory */
			if (i - 1 <= start) {
				return start ? start : len;
			}
			j = tsrm_realpath_r(path, start, i-1, ll, t, use_realpath, 1, NULL TSRMLS_CC);
			if (j > start) {
				j--;
				while (j > start && !IS_SLASH(path[j])) {
					j--;
				}
				if (!start) {
					/* leading '..' must not be removed in case of relative path */
					if (j == 0 && path[0] == '.' && path[1] == '.' &&
					    IS_SLASH(path[2])) {
						path[3] = '.';
						path[4] = '.';
						path[5] = DEFAULT_SLASH;
						j = 5;
					} else if (j > 0 && 
				               path[j+1] == '.' && path[j+2] == '.' &&
				               IS_SLASH(path[j+3])) {
						j += 4;
						path[j++] = '.';
						path[j++] = '.';
						path[j] = DEFAULT_SLASH;
					}
				}
			} else if (!start && !j) {
				/* leading '..' must not be removed in case of relative path */
				path[0] = '.';
				path[1] = '.';
				path[2] = DEFAULT_SLASH;
				j = 2;
			}
			return j;
		}
	
		path[len] = 0;

		save = (use_realpath != CWD_EXPAND);

		if (start && save && CWDG(realpath_cache_size_limit)) {
			/* cache lookup for absolute path */
			if (!*t) {
				*t = time(0);
			}
		    if ((bucket = realpath_cache_find(path, len, *t TSRMLS_CC)) != NULL) {
		    	if (is_dir && !bucket->is_dir) {
					/* not a directory */
					return -1;
		    	} else {
		    		if (link_is_dir) {
		    			*link_is_dir = bucket->is_dir;
		    		}
					memcpy(path, bucket->realpath, bucket->realpath_len + 1);
				    return bucket->realpath_len;
				}
	    		}
		}

#ifdef TSRM_WIN32
		if (save && (hFind = FindFirstFile(path, &data)) == INVALID_HANDLE_VALUE) {
			if (use_realpath == CWD_REALPATH) {
				/* file not found */
				return -1;
			}
			/* continue resolution anyway but don't save result in the cache */
			save = 0;
		}
		
		if (save) {
			FindClose(hFind);
		}

		tmp = tsrm_do_alloca(len+1, use_heap);
		memcpy(tmp, path, len+1);

		if(save && (data.dwFileAttributes & FILE_ATTRIBUTE_REPARSE_POINT)) {
			/* File is a reparse point. Get the target */
			HANDLE hLink = NULL;
			REPARSE_DATA_BUFFER * pbuffer;
			unsigned int retlength = 0, rname_off = 0;
			int bufindex = 0, rname_len = 0, isabsolute = 0;
			wchar_t * reparsetarget;

			if(++(*ll) > LINK_MAX) {
				return -1;
			}

			hLink = CreateFile(path, GENERIC_READ, 0, NULL, OPEN_EXISTING, FILE_FLAG_OPEN_REPARSE_POINT|FILE_FLAG_BACKUP_SEMANTICS, NULL);
			if(hLink == INVALID_HANDLE_VALUE) {
				return -1;
			}

			pbuffer = (REPARSE_DATA_BUFFER *)tsrm_do_alloca(MAXIMUM_REPARSE_DATA_BUFFER_SIZE, use_heap_large);
			if(!DeviceIoControl(hLink, FSCTL_GET_REPARSE_POINT, NULL, 0, pbuffer,  MAXIMUM_REPARSE_DATA_BUFFER_SIZE, &retlength, NULL)) {
				tsrm_free_alloca(pbuffer, use_heap_large);
				CloseHandle(hLink);
				return -1;
			}

			CloseHandle(hLink);

			if(pbuffer->ReparseTag == IO_REPARSE_TAG_SYMLINK) {
				rname_len = pbuffer->SymbolicLinkReparseBuffer.PrintNameLength/2;
				rname_off = pbuffer->SymbolicLinkReparseBuffer.PrintNameOffset/2;
				reparsetarget = pbuffer->SymbolicLinkReparseBuffer.ReparseTarget;
				isabsolute = (pbuffer->SymbolicLinkReparseBuffer.Flags == 0) ? 1 : 0;
			}
			else if(pbuffer->ReparseTag == IO_REPARSE_TAG_MOUNT_POINT) {
				rname_len = pbuffer->MountPointReparseBuffer.PrintNameLength/2;
				rname_off = pbuffer->MountPointReparseBuffer.PrintNameOffset/2;
				reparsetarget = pbuffer->MountPointReparseBuffer.ReparseTarget;
				isabsolute = 1;
			}
			else {
				tsrm_free_alloca(pbuffer, use_heap_large);
				return -1;
			}

			/* Convert wide string to narrow string */
			for(bufindex = 0; bufindex < rname_len; bufindex++) {
				*(path + bufindex) = (char)(reparsetarget[rname_off + bufindex]);
			}

			*(path + bufindex) = 0;
			tsrm_free_alloca(pbuffer, use_heap_large);
			j = bufindex;

			if(isabsolute == 1) {
				/* use_realpath is 0 in the call below coz path is absolute*/
				j = tsrm_realpath_r(path, 0, j, ll, t, 0, is_dir, &directory TSRMLS_CC);
				if(j < 0) {
					tsrm_free_alloca(tmp, use_heap);
					return -1;
				}
			}
			else {
				if(i + j >= MAXPATHLEN - 1) {
					tsrm_free_alloca(tmp, use_heap);
					return -1;
				}

				memmove(path+i, path, j+1);
				memcpy(path, tmp, i-1);
				path[i-1] = DEFAULT_SLASH;
				j  = tsrm_realpath_r(path, start, i + j, ll, t, use_realpath, is_dir, &directory TSRMLS_CC);
				if(j < 0) {
					tsrm_free_alloca(tmp, use_heap);
					return -1;
				}
			}

			if(link_is_dir) {
				*link_is_dir = directory;
			}
		}
		else {
			if (save) {
				directory = (data.dwFileAttributes & FILE_ATTRIBUTE_DIRECTORY) != 0;
				if (is_dir && !directory) {
					/* not a directory */
					return -1;
				}
			}

#elif defined(NETWARE)
		save = 0;
		tmp = tsrm_do_alloca(len+1, use_heap);
		memcpy(tmp, path, len+1);
#else
		if (save && lstat(path, &st) < 0) {
			if (use_realpath == CWD_REALPATH) {
				/* file not found */
				return -1;
			}
			/* continue resolution anyway but don't save result in the cache */
			save = 0;
		}

		tmp = tsrm_do_alloca(len+1, use_heap);
		memcpy(tmp, path, len+1);

		if (save && S_ISLNK(st.st_mode)) {
			if (++(*ll) > LINK_MAX || (j = readlink(tmp, path, MAXPATHLEN)) < 0) {
			    /* too many links or broken symlinks */
				tsrm_free_alloca(tmp, use_heap);
				return -1;
			}
			path[j] = 0;
			if (IS_ABSOLUTE_PATH(path, j)) {
				j = tsrm_realpath_r(path, 1, j, ll, t, use_realpath, is_dir, &directory TSRMLS_CC);
				if (j < 0) {
					tsrm_free_alloca(tmp, use_heap);
					return -1;
				}
			} else {
			    if (i + j >= MAXPATHLEN-1) {
					tsrm_free_alloca(tmp, use_heap);
					return -1; /* buffer overflow */
			    }
				memmove(path+i, path, j+1);
				memcpy(path, tmp, i-1);
				path[i-1] = DEFAULT_SLASH;
				j = tsrm_realpath_r(path, start, i + j, ll, t, use_realpath, is_dir, &directory TSRMLS_CC);
				if (j < 0) {
					tsrm_free_alloca(tmp, use_heap);
					return -1;
				}
			}
			if (link_is_dir) {
				*link_is_dir = directory;
			}
		} else {
			if (save) {
				directory = S_ISDIR(st.st_mode);
				if (link_is_dir) {
					*link_is_dir = directory;
				}
				if (is_dir && !directory) {
					/* not a directory */
					return -1;
				}
			}
#endif
			if (i - 1 <= start) {
				j = start;
			} else {
				/* some leading directories may be unaccessable */
				j = tsrm_realpath_r(path, start, i-1, ll, t, save ? CWD_FILEPATH : use_realpath, 1, NULL TSRMLS_CC);
				if (j > start) {
					path[j++] = DEFAULT_SLASH;
				}
			}
#ifdef TSRM_WIN32
			if (j < 0 || j + len - i >= MAXPATHLEN-1) {
				tsrm_free_alloca(tmp, use_heap);
				return -1;
			}
			if (save) {
				i = strlen(data.cFileName);
				memcpy(path+j, data.cFileName, i+1);
				j += i;
			} else {
				/* use the original file or directory name as it wasn't found */
				memcpy(path+j, tmp+i, len-i+1);
				j += (len-i);
			}
		}
#else
			if (j < 0 || j + len - i >= MAXPATHLEN-1) {
				tsrm_free_alloca(tmp, use_heap);
				return -1;
			}
			memcpy(path+j, tmp+i, len-i+1);
			j += (len-i);
		}
#endif

		if (save && start && CWDG(realpath_cache_size_limit)) {
			/* save absolute path in the cache */
			realpath_cache_add(tmp, len, path, j, directory, *t TSRMLS_CC);
		}

		tsrm_free_alloca(tmp, use_heap);
		return j;
	}
}
/* }}} */

/* Resolve path relatively to state and put the real path into state */
/* returns 0 for ok, 1 for error */
CWD_API int virtual_file_ex(cwd_state *state, const char *path, verify_path_func verify_path, int use_realpath) /* {{{ */
{
	int path_length = strlen(path);
	char resolved_path[MAXPATHLEN];
	int start = 1;
	int ll = 0;
	time_t t;
	int ret;
	int add_slash;
	TSRMLS_FETCH();

	if (path_length == 0 || path_length >= MAXPATHLEN-1) {
		return 1;
	}

#if VIRTUAL_CWD_DEBUG
	fprintf(stderr,"cwd = %s path = %s\n", state->cwd, path);
#endif

	/* cwd_length can be 0 when getcwd() fails.
	 * This can happen under solaris when a dir does not have read permissions
	 * but *does* have execute permissions */
	if (!IS_ABSOLUTE_PATH(path, path_length)) {
		if (state->cwd_length == 0) {
			/* resolve relative path */
			start = 0;
			memcpy(resolved_path , path, path_length + 1);
		} else {
			int state_cwd_length = state->cwd_length;

#ifdef TSRM_WIN32
			if (IS_SLASH(path[0])) {
				if (state->cwd[1] == ':') {
					/* Copy only the drive name */
					state_cwd_length = 2;
				} else if (IS_UNC_PATH(state->cwd, state->cwd_length)) {
					/* Copy only the share name */
					state_cwd_length = 2;
					while (IS_SLASH(state->cwd[state_cwd_length])) {
						state_cwd_length++;
					}						 
					while (state->cwd[state_cwd_length] &&
					       !IS_SLASH(state->cwd[state_cwd_length])) {
						state_cwd_length++;
					}						 
					while (IS_SLASH(state->cwd[state_cwd_length])) {
						state_cwd_length++;
					}						 
					while (state->cwd[state_cwd_length] &&
					       !IS_SLASH(state->cwd[state_cwd_length])) {
						state_cwd_length++;
					}						 
				}
			}
#endif
			if (path_length + state_cwd_length + 1 >= MAXPATHLEN-1) {
				return 1;
			}
			memcpy(resolved_path, state->cwd, state_cwd_length);
			resolved_path[state_cwd_length] = DEFAULT_SLASH;
			memcpy(resolved_path + state_cwd_length + 1, path, path_length + 1);
			path_length += state_cwd_length + 1;
		}
	} else {		
#ifdef TSRM_WIN32
		if (path_length > 2 && path[1] == ':' && !IS_SLASH(path[2])) {
			resolved_path[0] = path[0];
			resolved_path[1] = ':';
			resolved_path[2] = DEFAULT_SLASH;
			memcpy(resolved_path + 3, path + 2, path_length - 1);
			path_length++;
		} else
#endif
		memcpy(resolved_path, path, path_length + 1);
	} 

#ifdef TSRM_WIN32
	if (memchr(resolved_path, '*', path_length) ||
	    memchr(resolved_path, '?', path_length)) {
		return 1;
	}
#endif

#ifdef TSRM_WIN32
	if (IS_UNC_PATH(resolved_path, path_length)) {
		/* skip UNC name */
		resolved_path[0] = DEFAULT_SLASH;
		resolved_path[1] = DEFAULT_SLASH;
		start = 2;
		while (!IS_SLASH(resolved_path[start])) {
			if (resolved_path[start] == 0) {
				goto verify;
			}
			resolved_path[start] = toupper(resolved_path[start]);
			start++;
		}
		resolved_path[start++] = DEFAULT_SLASH;
		while (!IS_SLASH(resolved_path[start])) {
			if (resolved_path[start] == 0) {
				goto verify;
			}
			resolved_path[start] = toupper(resolved_path[start]);
			start++;
		}
		resolved_path[start++] = DEFAULT_SLASH;
	} else if (IS_ABSOLUTE_PATH(resolved_path, path_length)) {
		/* skip DRIVE name */
		resolved_path[0] = toupper(resolved_path[0]);
		resolved_path[2] = DEFAULT_SLASH;
		start = 3;
	}
#elif defined(NETWARE)
	if (IS_ABSOLUTE_PATH(resolved_path, path_length)) {
		/* skip VOLUME name */
		start = 0;
		while (start != ':') {
			if (resolved_path[start] == 0) return -1;
			start++;
		}
		start++;
		if (!IS_SLASH(resolved_path[start])) return -1;
		resolved_path[start++] = DEFAULT_SLASH;
	}
#endif

	add_slash = (use_realpath != CWD_REALPATH) && path_length > 0 && IS_SLASH(resolved_path[path_length-1]);
	t = CWDG(realpath_cache_ttl) ? 0 : -1;
	path_length = tsrm_realpath_r(resolved_path, start, path_length, &ll, &t, use_realpath, 0, NULL TSRMLS_CC);
	
	if (path_length < 0) {
		errno = ENOENT;
		return 1;
	}
	
	if (!start && !path_length) {
		resolved_path[path_length++] = '.';
	}
	if (add_slash && path_length && !IS_SLASH(resolved_path[path_length-1])) {
		if (path_length >= MAXPATHLEN-1) {
			return -1;
		}
		resolved_path[path_length++] = DEFAULT_SLASH;
	}
	resolved_path[path_length] = 0;

#ifdef TSRM_WIN32
verify:
#endif
	if (verify_path) {
		cwd_state old_state;

		CWD_STATE_COPY(&old_state, state);
		state->cwd_length = path_length;
		state->cwd = (char *) realloc(state->cwd, state->cwd_length+1);
		memcpy(state->cwd, resolved_path, state->cwd_length+1);
		if (verify_path(state)) {
			CWD_STATE_FREE(state);
			*state = old_state;
			ret = 1;
		} else {
			CWD_STATE_FREE(&old_state);
			ret = 0;
		}
	} else {
		state->cwd_length = path_length;
		state->cwd = (char *) realloc(state->cwd, state->cwd_length+1);
		memcpy(state->cwd, resolved_path, state->cwd_length+1);
		ret = 0;
	}
	
#if VIRTUAL_CWD_DEBUG
	fprintf (stderr, "virtual_file_ex() = %s\n",state->cwd);
#endif
	return (ret);
}
/* }}} */

CWD_API int virtual_chdir(const char *path TSRMLS_DC) /* {{{ */
{
	return virtual_file_ex(&CWDG(cwd), path, php_is_dir_ok, CWD_REALPATH)?-1:0;
}
/* }}} */

CWD_API int virtual_chdir_file(const char *path, int (*p_chdir)(const char *path TSRMLS_DC) TSRMLS_DC) /* {{{ */
{
	int length = strlen(path);
	char *temp;
	int retval;
	TSRM_ALLOCA_FLAG(use_heap)

	if (length == 0) {
		return 1; /* Can't cd to empty string */
	}	
	while(--length >= 0 && !IS_SLASH(path[length])) {
	}

	if (length == -1) {
		/* No directory only file name */
		errno = ENOENT;
		return -1;
	}

	if (length == COPY_WHEN_ABSOLUTE(path) && IS_ABSOLUTE_PATH(path, length+1)) { /* Also use trailing slash if this is absolute */
		length++;
	}
	temp = (char *) tsrm_do_alloca(length+1, use_heap);
	memcpy(temp, path, length);
	temp[length] = 0;
#if VIRTUAL_CWD_DEBUG
	fprintf (stderr, "Changing directory to %s\n", temp);
#endif
	retval = p_chdir(temp TSRMLS_CC);
	tsrm_free_alloca(temp, use_heap);
	return retval;
}
/* }}} */

CWD_API char *virtual_realpath(const char *path, char *real_path TSRMLS_DC) /* {{{ */
{
	cwd_state new_state;
	char *retval;
	char cwd[MAXPATHLEN];

	/* realpath("") returns CWD */
	if (!*path) {
		new_state.cwd = (char*)malloc(1);
		new_state.cwd[0] = '\0';
		new_state.cwd_length = 0;		
	    if (VCWD_GETCWD(cwd, MAXPATHLEN)) {
		    path = cwd;
		}
	} else if (!IS_ABSOLUTE_PATH(path, strlen(path))) {
		CWD_STATE_COPY(&new_state, &CWDG(cwd));
	} else {
		new_state.cwd = (char*)malloc(1);
		new_state.cwd[0] = '\0';
		new_state.cwd_length = 0;		
	}
	
	if (virtual_file_ex(&new_state, path, NULL, CWD_REALPATH)==0) {
		int len = new_state.cwd_length>MAXPATHLEN-1?MAXPATHLEN-1:new_state.cwd_length;

		memcpy(real_path, new_state.cwd, len);
		real_path[len] = '\0';
		retval = real_path;
	} else {
		retval = NULL;
	}

	CWD_STATE_FREE(&new_state);

	return retval;
}
/* }}} */

CWD_API int virtual_filepath_ex(const char *path, char **filepath, verify_path_func verify_path TSRMLS_DC) /* {{{ */
{
	cwd_state new_state;
	int retval;

	CWD_STATE_COPY(&new_state, &CWDG(cwd));
	retval = virtual_file_ex(&new_state, path, verify_path, CWD_FILEPATH);

	*filepath = new_state.cwd;

	return retval;

}
/* }}} */

CWD_API int virtual_filepath(const char *path, char **filepath TSRMLS_DC) /* {{{ */
{
	return virtual_filepath_ex(path, filepath, php_is_file_ok TSRMLS_CC);
}
/* }}} */

CWD_API FILE *virtual_fopen(const char *path, const char *mode TSRMLS_DC) /* {{{ */
{
	cwd_state new_state;
	FILE *f;

	if (path[0] == '\0') { /* Fail to open empty path */
		return NULL;
	}

	CWD_STATE_COPY(&new_state, &CWDG(cwd));
	if (virtual_file_ex(&new_state, path, NULL, CWD_FILEPATH)) {
		CWD_STATE_FREE(&new_state);
		return NULL;
	}

	f = fopen(new_state.cwd, mode);

	CWD_STATE_FREE(&new_state);
	return f;
}
/* }}} */

CWD_API int virtual_access(const char *pathname, int mode TSRMLS_DC) /* {{{ */
{
	cwd_state new_state;
	int ret;
	
	CWD_STATE_COPY(&new_state, &CWDG(cwd));
	if (virtual_file_ex(&new_state, pathname, NULL, CWD_REALPATH)) {
		CWD_STATE_FREE(&new_state);
		return -1;
	}

#if defined(TSRM_WIN32)
	ret = tsrm_win32_access(new_state.cwd, mode);
#else
	ret = access(new_state.cwd, mode);
#endif
	
	CWD_STATE_FREE(&new_state);
	
	return ret;
}
/* }}} */

#if HAVE_UTIME
#ifdef TSRM_WIN32
static void UnixTimeToFileTime(time_t t, LPFILETIME pft) /* {{{ */
{
	// Note that LONGLONG is a 64-bit value
	LONGLONG ll;

	ll = Int32x32To64(t, 10000000) + 116444736000000000;
	pft->dwLowDateTime = (DWORD)ll;
	pft->dwHighDateTime = ll >> 32;
}
/* }}} */

static int win32_utime(const char *filename, struct utimbuf *buf) /* {{{ */
{
	FILETIME mtime, atime;
	HANDLE hFile; 

	hFile = CreateFile(filename, GENERIC_WRITE, FILE_SHARE_WRITE|FILE_SHARE_READ, NULL,
				 OPEN_ALWAYS, FILE_FLAG_BACKUP_SEMANTICS, NULL);

	/* OPEN_ALWAYS mode sets the last error to ERROR_ALREADY_EXISTS but 
	   the CreateFile operation succeeds */
	if (GetLastError() == ERROR_ALREADY_EXISTS) {
		SetLastError(0);
	}

	if ( hFile == INVALID_HANDLE_VALUE ) {
		return -1;
	}

	if (!buf) {
		SYSTEMTIME st;
		GetSystemTime(&st);
		SystemTimeToFileTime(&st, &mtime);
		atime = mtime;
	} else {
		UnixTimeToFileTime(buf->modtime, &mtime);
		UnixTimeToFileTime(buf->actime, &atime);
	}
	if (!SetFileTime(hFile, NULL, &atime, &mtime)) {
		CloseHandle(hFile);
		return -1;
	}
	CloseHandle(hFile);
	return 1;
}
/* }}} */
#endif

CWD_API int virtual_utime(const char *filename, struct utimbuf *buf TSRMLS_DC) /* {{{ */
{
	cwd_state new_state;
	int ret;

	CWD_STATE_COPY(&new_state, &CWDG(cwd));
	if (virtual_file_ex(&new_state, filename, NULL, CWD_REALPATH)) {
		CWD_STATE_FREE(&new_state);
		return -1;
	}

#ifdef TSRM_WIN32
	ret = win32_utime(new_state.cwd, buf);
#else
	ret = utime(new_state.cwd, buf);
#endif

	CWD_STATE_FREE(&new_state);
	return ret;
}
/* }}} */
#endif

CWD_API int virtual_chmod(const char *filename, mode_t mode TSRMLS_DC) /* {{{ */
{
	cwd_state new_state;
	int ret;

	CWD_STATE_COPY(&new_state, &CWDG(cwd));
	if (virtual_file_ex(&new_state, filename, NULL, CWD_REALPATH)) {
		CWD_STATE_FREE(&new_state);
		return -1;
	}

	ret = chmod(new_state.cwd, mode);

	CWD_STATE_FREE(&new_state);
	return ret;
}
/* }}} */

#if !defined(TSRM_WIN32) && !defined(NETWARE)
CWD_API int virtual_chown(const char *filename, uid_t owner, gid_t group, int link TSRMLS_DC) /* {{{ */
{
	cwd_state new_state;
	int ret;

	CWD_STATE_COPY(&new_state, &CWDG(cwd));
	if (virtual_file_ex(&new_state, filename, NULL, CWD_REALPATH)) {
		CWD_STATE_FREE(&new_state);
		return -1;
	}

	if (link) {
#if HAVE_LCHOWN
		ret = lchown(new_state.cwd, owner, group);
#else
		ret = -1;
#endif
	} else {
		ret = chown(new_state.cwd, owner, group);
	}

	CWD_STATE_FREE(&new_state);
	return ret;
}
/* }}} */
#endif

CWD_API int virtual_open(const char *path TSRMLS_DC, int flags, ...) /* {{{ */
{
	cwd_state new_state;
	int f;

	CWD_STATE_COPY(&new_state, &CWDG(cwd));
	if (virtual_file_ex(&new_state, path, NULL, CWD_FILEPATH)) {
		CWD_STATE_FREE(&new_state);
		return -1;
	}

	if (flags & O_CREAT) {
		mode_t mode;
		va_list arg;

		va_start(arg, flags);
		mode = (mode_t) va_arg(arg, int);
		va_end(arg);

		f = open(new_state.cwd, flags, mode);
	} else {
		f = open(new_state.cwd, flags);
	}	
	CWD_STATE_FREE(&new_state);
	return f;
}
/* }}} */

CWD_API int virtual_creat(const char *path, mode_t mode TSRMLS_DC) /* {{{ */
{
	cwd_state new_state;
	int f;

	CWD_STATE_COPY(&new_state, &CWDG(cwd));
	if (virtual_file_ex(&new_state, path, NULL, CWD_FILEPATH)) {
		CWD_STATE_FREE(&new_state);
		return -1;
	}

	f = creat(new_state.cwd,  mode);

	CWD_STATE_FREE(&new_state);
	return f;
}
/* }}} */

CWD_API int virtual_rename(char *oldname, char *newname TSRMLS_DC) /* {{{ */
{
	cwd_state old_state;
	cwd_state new_state;
	int retval;

	CWD_STATE_COPY(&old_state, &CWDG(cwd));
	if (virtual_file_ex(&old_state, oldname, NULL, CWD_EXPAND)) {
		CWD_STATE_FREE(&old_state);
		return -1;
	}
	oldname = old_state.cwd;

	CWD_STATE_COPY(&new_state, &CWDG(cwd));
	if (virtual_file_ex(&new_state, newname, NULL, CWD_EXPAND)) {
		CWD_STATE_FREE(&old_state);
		CWD_STATE_FREE(&new_state);
		return -1;
	}
	newname = new_state.cwd;

	/* rename on windows will fail if newname already exists.
	   MoveFileEx has to be used */
#ifdef TSRM_WIN32
	retval = (MoveFileEx(oldname, newname, MOVEFILE_REPLACE_EXISTING) == 0) ? -1 : 0;
#else
	retval = rename(oldname, newname);
#endif

	CWD_STATE_FREE(&old_state);
	CWD_STATE_FREE(&new_state);

	return retval;
}
/* }}} */

CWD_API int virtual_stat(const char *path, struct stat *buf TSRMLS_DC) /* {{{ */
{
	cwd_state new_state;
	int retval;

	CWD_STATE_COPY(&new_state, &CWDG(cwd));
	if (virtual_file_ex(&new_state, path, NULL, CWD_REALPATH)) {
		CWD_STATE_FREE(&new_state);
		return -1;
	}

	retval = php_sys_stat(new_state.cwd, buf);

	CWD_STATE_FREE(&new_state);
	return retval;
}
/* }}} */

#if !defined(TSRM_WIN32)
CWD_API int virtual_lstat(const char *path, struct stat *buf TSRMLS_DC) /* {{{ */
{
	cwd_state new_state;
	int retval;

	CWD_STATE_COPY(&new_state, &CWDG(cwd));
	if (virtual_file_ex(&new_state, path, NULL, CWD_EXPAND)) {
		CWD_STATE_FREE(&new_state);
		return -1;
	}

	retval = lstat(new_state.cwd, buf);

	CWD_STATE_FREE(&new_state);
	return retval;
}
/* }}} */
#endif

CWD_API int virtual_unlink(const char *path TSRMLS_DC) /* {{{ */
{
	cwd_state new_state;
	int retval;

	CWD_STATE_COPY(&new_state, &CWDG(cwd));
	if (virtual_file_ex(&new_state, path, NULL, CWD_EXPAND)) {
		CWD_STATE_FREE(&new_state);
		return -1;
	}

	retval = unlink(new_state.cwd);

	CWD_STATE_FREE(&new_state);
	return retval;
}
/* }}} */

CWD_API int virtual_mkdir(const char *pathname, mode_t mode TSRMLS_DC) /* {{{ */
{
	cwd_state new_state;
	int retval;

	CWD_STATE_COPY(&new_state, &CWDG(cwd));
	if (virtual_file_ex(&new_state, pathname, NULL, CWD_FILEPATH)) {
		CWD_STATE_FREE(&new_state);
		return -1;
	}

#ifdef TSRM_WIN32
	retval = mkdir(new_state.cwd);
#else
	retval = mkdir(new_state.cwd, mode);
#endif
	CWD_STATE_FREE(&new_state);
	return retval;
}
/* }}} */

CWD_API int virtual_rmdir(const char *pathname TSRMLS_DC) /* {{{ */
{
	cwd_state new_state;
	int retval;

	CWD_STATE_COPY(&new_state, &CWDG(cwd));
	if (virtual_file_ex(&new_state, pathname, NULL, CWD_EXPAND)) {
		CWD_STATE_FREE(&new_state);
		return -1;
	}

	retval = rmdir(new_state.cwd);

	CWD_STATE_FREE(&new_state);
	return retval;
}
/* }}} */

#ifdef TSRM_WIN32
DIR *opendir(const char *name);
#endif

CWD_API DIR *virtual_opendir(const char *pathname TSRMLS_DC) /* {{{ */
{
	cwd_state new_state;
	DIR *retval;

	CWD_STATE_COPY(&new_state, &CWDG(cwd));
	if (virtual_file_ex(&new_state, pathname, NULL, CWD_REALPATH)) {
		CWD_STATE_FREE(&new_state);
		return NULL;
	}

	retval = opendir(new_state.cwd);

	CWD_STATE_FREE(&new_state);
	return retval;
}
/* }}} */

#ifdef TSRM_WIN32
CWD_API FILE *virtual_popen(const char *command, const char *type TSRMLS_DC) /* {{{ */
{
	return popen_ex(command, type, CWDG(cwd).cwd, NULL);
}
/* }}} */
#elif defined(NETWARE)
/* On NetWare, the trick of prepending "cd cwd; " doesn't work so we need to perform
   a VCWD_CHDIR() and mutex it
 */
CWD_API FILE *virtual_popen(const char *command, const char *type TSRMLS_DC) /* {{{ */
{
	char prev_cwd[MAXPATHLEN];
	char *getcwd_result;
	FILE *retval;

	getcwd_result = VCWD_GETCWD(prev_cwd, MAXPATHLEN);
	if (!getcwd_result) {
		return NULL;
	}

#ifdef ZTS
	tsrm_mutex_lock(cwd_mutex);
#endif

	VCWD_CHDIR(CWDG(cwd).cwd);
	retval = popen(command, type);
	VCWD_CHDIR(prev_cwd);

#ifdef ZTS
	tsrm_mutex_unlock(cwd_mutex);
#endif

	return retval;
}
/* }}} */
#else /* Unix */
CWD_API FILE *virtual_popen(const char *command, const char *type TSRMLS_DC) /* {{{ */
{
	int command_length;
	int dir_length, extra = 0;
	char *command_line;
	char *ptr, *dir;
	FILE *retval;

	command_length = strlen(command);

	dir_length = CWDG(cwd).cwd_length;
	dir = CWDG(cwd).cwd;
	while (dir_length > 0) {
		if (*dir == '\'') extra+=3;
		dir++;
		dir_length--;
	}
	dir_length = CWDG(cwd).cwd_length;
	dir = CWDG(cwd).cwd;

	ptr = command_line = (char *) malloc(command_length + sizeof("cd '' ; ") + dir_length + extra+1+1);
	if (!command_line) {
		return NULL;
	}
	memcpy(ptr, "cd ", sizeof("cd ")-1);
	ptr += sizeof("cd ")-1;

	if (CWDG(cwd).cwd_length == 0) {
		*ptr++ = DEFAULT_SLASH;
	} else {
		*ptr++ = '\'';
		while (dir_length > 0) {
			switch (*dir) {
			case '\'':
				*ptr++ = '\'';
				*ptr++ = '\\';
				*ptr++ = '\'';
				/* fall-through */
			default:
				*ptr++ = *dir;
			}
			dir++;
			dir_length--;
		}
		*ptr++ = '\'';
	}
	
	*ptr++ = ' ';
	*ptr++ = ';';
	*ptr++ = ' ';

	memcpy(ptr, command, command_length+1);
	retval = popen(command_line, type);

	free(command_line);
	return retval;
}
/* }}} */
#endif

CWD_API char *tsrm_realpath(const char *path, char *real_path TSRMLS_DC) /* {{{ */
{
	cwd_state new_state;
	char cwd[MAXPATHLEN];

	/* realpath("") returns CWD */
	if (!*path) {
		new_state.cwd = (char*)malloc(1);
		new_state.cwd[0] = '\0';
		new_state.cwd_length = 0;		
	    if (VCWD_GETCWD(cwd, MAXPATHLEN)) {
		    path = cwd;
		}
	} else if (!IS_ABSOLUTE_PATH(path, strlen(path)) &&
	    VCWD_GETCWD(cwd, MAXPATHLEN)) {
		new_state.cwd = strdup(cwd);
		new_state.cwd_length = strlen(cwd);
	} else {
		new_state.cwd = (char*)malloc(1);
		new_state.cwd[0] = '\0';
		new_state.cwd_length = 0;		
	}

	if (virtual_file_ex(&new_state, path, NULL, CWD_REALPATH)) {
		free(new_state.cwd);
		return NULL;
	}

	if (real_path) {
		int copy_len = new_state.cwd_length>MAXPATHLEN-1 ? MAXPATHLEN-1 : new_state.cwd_length;
		memcpy(real_path, new_state.cwd, copy_len);
		real_path[copy_len] = '\0';
		free(new_state.cwd);
		return real_path;
	} else {
		return new_state.cwd;
	}
}
/* }}} */

/*
 * Local variables:
 * tab-width: 4
 * c-basic-offset: 4
 * End:
 */