runtime/bin/directory_linux.cc - sdk.git - Git at Google

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.

 #include "platform/globals.h"
 #if defined(TARGET_OS_LINUX)

 #include "bin/directory.h"

 #include <dirent.h>  // NOLINT
 #include <errno.h>  // NOLINT
 #include <stdlib.h>  // NOLINT
 #include <string.h>  // NOLINT
 #include <sys/param.h>  // NOLINT
 #include <sys/stat.h>  // NOLINT
 #include <unistd.h>  // NOLINT

 #include "bin/dartutils.h"
 #include "bin/file.h"
 #include "bin/platform.h"
 #include "platform/signal_blocker.h"

 namespace dart {
 namespace bin {

 PathBuffer::PathBuffer() : length_(0) {
   data_ = calloc(PATH_MAX + 1, sizeof(char));  // NOLINT
 }


 PathBuffer::~PathBuffer() {
   free(data_);
 }


 bool PathBuffer::AddW(const wchar_t* name) {
   UNREACHABLE();
   return false;
 }


 char* PathBuffer::AsString() const {
   return reinterpret_cast<char*>(data_);
 }


 wchar_t* PathBuffer::AsStringW() const {
   UNREACHABLE();
   return NULL;
 }


 const char* PathBuffer::AsScopedString() const {
   return DartUtils::ScopedCopyCString(AsString());
 }


 bool PathBuffer::Add(const char* name) {
   char* data = AsString();
   int written = snprintf(data + length_,
                          PATH_MAX - length_,
                          "%s",
                          name);
   data[PATH_MAX] = '\0';
   if ((written <= PATH_MAX - length_) &&
       (written >= 0) &&
       (static_cast<size_t>(written) == strnlen(name, PATH_MAX + 1))) {
     length_ += written;
     return true;
   } else {
     errno = ENAMETOOLONG;
     return false;
   }
 }


 void PathBuffer::Reset(intptr_t new_length) {
   length_ = new_length;
   AsString()[length_] = '\0';
 }


 // A linked list of symbolic links, with their unique file system identifiers.
 // These are scanned to detect loops while doing a recursive directory listing.
 struct LinkList {
   dev_t dev;
   ino64_t ino;
   LinkList* next;
 };


 ListType DirectoryListingEntry::Next(DirectoryListing* listing) {
   if (done_) {
     return kListDone;
   }

   if (lister_ == 0) {
     do {
       lister_ = reinterpret_cast<intptr_t>(
           opendir(listing->path_buffer().AsString()));
     } while ((lister_ == 0) && (errno == EINTR));

     if (lister_ == 0) {
       done_ = true;
       return kListError;
     }
     if (parent_ != NULL) {
       if (!listing->path_buffer().Add(File::PathSeparator())) {
         return kListError;
       }
     }
     path_length_ = listing->path_buffer().length();
   }
   // Reset.
   listing->path_buffer().Reset(path_length_);
   ResetLink();

   // Iterate the directory and post the directories and files to the
   // ports.
   int status = 0;
   dirent entry;
   dirent* result;
   status = NO_RETRY_EXPECTED(readdir_r(
       reinterpret_cast<DIR*>(lister_), &entry, &result));
   if ((status == 0) && (result != NULL)) {
     if (!listing->path_buffer().Add(entry.d_name)) {
       done_ = true;
       return kListError;
     }
     switch (entry.d_type) {
       case DT_DIR:
         if ((strcmp(entry.d_name, ".") == 0) ||
             (strcmp(entry.d_name, "..") == 0)) {
           return Next(listing);
         }
         return kListDirectory;
       case DT_REG:
         return kListFile;
       case DT_LNK:
         if (!listing->follow_links()) {
           return kListLink;
         }
         // Else fall through to next case.
         // Fall through.
       case DT_UNKNOWN: {
         // On some file systems the entry type is not determined by
         // readdir_r. For those and for links we use stat to determine
         // the actual entry type. Notice that stat returns the type of
         // the file pointed to.
         struct stat64 entry_info;
         int stat_success;
         stat_success = TEMP_FAILURE_RETRY(
             lstat64(listing->path_buffer().AsString(), &entry_info));
         if (stat_success == -1) {
           return kListError;
         }
         if (listing->follow_links() && S_ISLNK(entry_info.st_mode)) {
           // Check to see if we are in a loop created by a symbolic link.
           LinkList current_link = { entry_info.st_dev,
                                     entry_info.st_ino,
                                     link_ };
           LinkList* previous = link_;
           while (previous != NULL) {
             if ((previous->dev == current_link.dev) &&
                 (previous->ino == current_link.ino)) {
               // Report the looping link as a link, rather than following it.
               return kListLink;
             }
             previous = previous->next;
           }
           stat_success = TEMP_FAILURE_RETRY(
               stat64(listing->path_buffer().AsString(), &entry_info));
           if (stat_success == -1) {
             // Report a broken link as a link, even if follow_links is true.
             return kListLink;
           }
           if (S_ISDIR(entry_info.st_mode)) {
             // Recurse into the subdirectory with current_link added to the
             // linked list of seen file system links.
             link_ = new LinkList(current_link);
             if ((strcmp(entry.d_name, ".") == 0) ||
                 (strcmp(entry.d_name, "..") == 0)) {
               return Next(listing);
             }
             return kListDirectory;
           }
         }
         if (S_ISDIR(entry_info.st_mode)) {
           if ((strcmp(entry.d_name, ".") == 0) ||
               (strcmp(entry.d_name, "..") == 0)) {
             return Next(listing);
           }
           return kListDirectory;
         } else if (S_ISREG(entry_info.st_mode)) {
           return kListFile;
         } else if (S_ISLNK(entry_info.st_mode)) {
           return kListLink;
         }
       }

       default:
         break;
     }
   }
   done_ = true;

   if (status != 0) {
     errno = status;
     return kListError;
   }

   return kListDone;
 }


 DirectoryListingEntry::~DirectoryListingEntry() {
   ResetLink();
   if (lister_ != 0) {
     VOID_NO_RETRY_EXPECTED(closedir(reinterpret_cast<DIR*>(lister_)));
   }
 }


 void DirectoryListingEntry::ResetLink() {
   if ((link_ != NULL) && ((parent_ == NULL) || (parent_->link_ != link_))) {
     delete link_;
     link_ = NULL;
   }
   if (parent_ != NULL) {
     link_ = parent_->link_;
   }
 }


 static bool DeleteRecursively(PathBuffer* path);


 static bool DeleteFile(char* file_name,
                        PathBuffer* path) {
   return path->Add(file_name) &&
       (NO_RETRY_EXPECTED(unlink(path->AsString())) == 0);
 }


 static bool DeleteDir(char* dir_name,
                       PathBuffer* path) {
   if ((strcmp(dir_name, ".") == 0) || (strcmp(dir_name, "..") == 0)) {
     return true;
   }
   return path->Add(dir_name) && DeleteRecursively(path);
 }


 static bool DeleteRecursively(PathBuffer* path) {
   // Do not recurse into links for deletion. Instead delete the link.
   // If it's a file, delete it.
   struct stat64 st;
   if (TEMP_FAILURE_RETRY(lstat64(path->AsString(), &st)) == -1) {
     return false;
   } else if (S_ISREG(st.st_mode) || S_ISLNK(st.st_mode)) {
     return (NO_RETRY_EXPECTED(unlink(path->AsString())) == 0);
   }

   if (!path->Add(File::PathSeparator())) {
     return false;
   }

   // Not a link. Attempt to open as a directory and recurse into the
   // directory.
   DIR* dir_pointer;
   do {
     dir_pointer = opendir(path->AsString());
   } while ((dir_pointer == NULL) && (errno == EINTR));
   if (dir_pointer == NULL) {
     return false;
   }

   // Iterate the directory and delete all files and directories.
   int path_length = path->length();
   dirent entry;
   dirent* result;
   while (NO_RETRY_EXPECTED(readdir_r(dir_pointer, &entry, &result)) == 0) {
     if (result == NULL) {
       // End of directory.
       return (NO_RETRY_EXPECTED(closedir(dir_pointer)) == 0) &&
              (NO_RETRY_EXPECTED(remove(path->AsString())) == 0);
     }
     bool ok = false;
     switch (entry.d_type) {
       case DT_DIR:
         ok = DeleteDir(entry.d_name, path);
         break;
       case DT_REG:
       case DT_LNK:
         // Treat all links as files. This will delete the link which
         // is what we want no matter if the link target is a file or a
         // directory.
         ok = DeleteFile(entry.d_name, path);
         break;
       case DT_UNKNOWN: {
         if (!path->Add(entry.d_name)) {
           break;
         }
         // On some file systems the entry type is not determined by
         // readdir_r. For those we use lstat to determine the entry
         // type.
         struct stat64 entry_info;
         if (TEMP_FAILURE_RETRY(lstat64(path->AsString(), &entry_info)) == -1) {
           break;
         }
         path->Reset(path_length);
         if (S_ISDIR(entry_info.st_mode)) {
           ok = DeleteDir(entry.d_name, path);
         } else if (S_ISREG(entry_info.st_mode) || S_ISLNK(entry_info.st_mode)) {
           // Treat links as files. This will delete the link which is
           // what we want no matter if the link target is a file or a
           // directory.
           ok = DeleteFile(entry.d_name, path);
         }
         break;
       }
       default:
         break;
     }
     if (!ok) {
       break;
     }
     path->Reset(path_length);
   }
   // Only happens if an error.
   ASSERT(errno != 0);
   int err = errno;
   VOID_NO_RETRY_EXPECTED(closedir(dir_pointer));
   errno = err;
   return false;
 }


 Directory::ExistsResult Directory::Exists(const char* dir_name) {
   struct stat64 entry_info;
   int success = TEMP_FAILURE_RETRY(stat64(dir_name, &entry_info));
   if (success == 0) {
     if (S_ISDIR(entry_info.st_mode)) {
       return EXISTS;
     } else {
       return DOES_NOT_EXIST;
     }
   } else {
     if ((errno == EACCES) ||
         (errno == EBADF) ||
         (errno == EFAULT) ||
         (errno == ENOMEM) ||
         (errno == EOVERFLOW)) {
       // Search permissions denied for one of the directories in the
       // path or a low level error occured. We do not know if the
       // directory exists.
       return UNKNOWN;
     }
     ASSERT((errno == ELOOP) ||
            (errno == ENAMETOOLONG) ||
            (errno == ENOENT) ||
            (errno == ENOTDIR));
     return DOES_NOT_EXIST;
   }
 }


 char* Directory::CurrentNoScope() {
   return getcwd(NULL, 0);
 }


 const char* Directory::Current() {
   char buffer[PATH_MAX];
   if (getcwd(buffer, PATH_MAX) == NULL) {
     return NULL;
   }
   return DartUtils::ScopedCopyCString(buffer);
 }


 bool Directory::SetCurrent(const char* path) {
   return (NO_RETRY_EXPECTED(chdir(path)) == 0);
 }


 bool Directory::Create(const char* dir_name) {
   // Create the directory with the permissions specified by the
   // process umask.
   int result = NO_RETRY_EXPECTED(mkdir(dir_name, 0777));
   // If the directory already exists, treat it as a success.
   if ((result == -1) && (errno == EEXIST)) {
     return (Exists(dir_name) == EXISTS);
   }
   return (result == 0);
 }


 const char* Directory::SystemTemp() {
   PathBuffer path;
   const char* temp_dir = getenv("TMPDIR");
   if (temp_dir == NULL) {
     temp_dir = getenv("TMP");
   }
   if (temp_dir == NULL) {
     temp_dir = "/tmp";
   }
   if (!path.Add(temp_dir)) {
     return NULL;
   }

   // Remove any trailing slash.
   char* result = path.AsString();
   int length = strlen(result);
   if ((length > 1) && (result[length - 1] == '/')) {
     result[length - 1] = '\0';
   }
   return path.AsScopedString();
 }


 const char* Directory::CreateTemp(const char* prefix) {
   // Returns a new, unused directory name, adding characters to the end
   // of prefix.  Creates the directory with the permissions specified
   // by the process umask.
   // The return value is Dart_ScopeAllocated.
   PathBuffer path;
   if (!path.Add(prefix)) {
     return NULL;
   }
   if (!path.Add("XXXXXX")) {
     // Pattern has overflowed.
     return NULL;
   }
   char* result;
   do {
     result = mkdtemp(path.AsString());
   } while ((result == NULL) && (errno == EINTR));
   if (result == NULL) {
     return NULL;
   }
   return path.AsScopedString();
 }


 bool Directory::Delete(const char* dir_name, bool recursive) {
   if (!recursive) {
     if ((File::GetType(dir_name, false) == File::kIsLink) &&
         (File::GetType(dir_name, true) == File::kIsDirectory)) {
       return NO_RETRY_EXPECTED(unlink(dir_name)) == 0;
     }
     return NO_RETRY_EXPECTED(rmdir(dir_name)) == 0;
   } else {
     PathBuffer path;
     if (!path.Add(dir_name)) {
       return false;
     }
     return DeleteRecursively(&path);
   }
 }


 bool Directory::Rename(const char* path, const char* new_path) {
   ExistsResult exists = Exists(path);
   if (exists != EXISTS) {
     return false;
   }
   return (NO_RETRY_EXPECTED(rename(path, new_path)) == 0);
 }

 }  // namespace bin
 }  // namespace dart

 #endif  // defined(TARGET_OS_LINUX)
	// Copyright (c) 2012, the Dart project authors. Please see the AUTHORS file
	// for details. All rights reserved. Use of this source code is governed by a
	// BSD-style license that can be found in the LICENSE file.

	#include "platform/globals.h"
	#if defined(TARGET_OS_LINUX)

	#include "bin/directory.h"

	#include <dirent.h> // NOLINT
	#include <errno.h> // NOLINT
	#include <stdlib.h> // NOLINT
	#include <string.h> // NOLINT
	#include <sys/param.h> // NOLINT
	#include <sys/stat.h> // NOLINT
	#include <unistd.h> // NOLINT

	#include "bin/dartutils.h"
	#include "bin/file.h"
	#include "bin/platform.h"
	#include "platform/signal_blocker.h"

	namespace dart {
	namespace bin {

	PathBuffer::PathBuffer() : length_(0) {
	data_ = calloc(PATH_MAX + 1, sizeof(char)); // NOLINT
	}


	PathBuffer::~PathBuffer() {
	free(data_);
	}


	bool PathBuffer::AddW(const wchar_t* name) {
	UNREACHABLE();
	return false;
	}


	char* PathBuffer::AsString() const {
	return reinterpret_cast<char*>(data_);
	}


	wchar_t* PathBuffer::AsStringW() const {
	UNREACHABLE();
	return NULL;
	}


	const char* PathBuffer::AsScopedString() const {
	return DartUtils::ScopedCopyCString(AsString());
	}


	bool PathBuffer::Add(const char* name) {
	char* data = AsString();
	int written = snprintf(data + length_,
	PATH_MAX - length_,
	"%s",
	name);
	data[PATH_MAX] = '\0';
	if ((written <= PATH_MAX - length_) &&
	(written >= 0) &&
	(static_cast<size_t>(written) == strnlen(name, PATH_MAX + 1))) {
	length_ += written;
	return true;
	} else {
	errno = ENAMETOOLONG;
	return false;
	}
	}


	void PathBuffer::Reset(intptr_t new_length) {
	length_ = new_length;
	AsString()[length_] = '\0';
	}


	// A linked list of symbolic links, with their unique file system identifiers.
	// These are scanned to detect loops while doing a recursive directory listing.
	struct LinkList {
	dev_t dev;
	ino64_t ino;
	LinkList* next;
	};


	ListType DirectoryListingEntry::Next(DirectoryListing* listing) {
	if (done_) {
	return kListDone;
	}

	if (lister_ == 0) {
	do {
	lister_ = reinterpret_cast<intptr_t>(
	opendir(listing->path_buffer().AsString()));
	} while ((lister_ == 0) && (errno == EINTR));

	if (lister_ == 0) {
	done_ = true;
	return kListError;
	}
	if (parent_ != NULL) {
	if (!listing->path_buffer().Add(File::PathSeparator())) {
	return kListError;
	}
	}
	path_length_ = listing->path_buffer().length();
	}
	// Reset.
	listing->path_buffer().Reset(path_length_);
	ResetLink();

	// Iterate the directory and post the directories and files to the
	// ports.
	int status = 0;
	dirent entry;
	dirent* result;
	status = NO_RETRY_EXPECTED(readdir_r(
	reinterpret_cast<DIR*>(lister_), &entry, &result));
	if ((status == 0) && (result != NULL)) {
	if (!listing->path_buffer().Add(entry.d_name)) {
	done_ = true;
	return kListError;
	}
	switch (entry.d_type) {
	case DT_DIR:
	if ((strcmp(entry.d_name, ".") == 0) \|\|
	(strcmp(entry.d_name, "..") == 0)) {
	return Next(listing);
	}
	return kListDirectory;
	case DT_REG:
	return kListFile;
	case DT_LNK:
	if (!listing->follow_links()) {
	return kListLink;
	}
	// Else fall through to next case.
	// Fall through.
	case DT_UNKNOWN: {
	// On some file systems the entry type is not determined by
	// readdir_r. For those and for links we use stat to determine
	// the actual entry type. Notice that stat returns the type of
	// the file pointed to.
	struct stat64 entry_info;
	int stat_success;
	stat_success = TEMP_FAILURE_RETRY(
	lstat64(listing->path_buffer().AsString(), &entry_info));
	if (stat_success == -1) {
	return kListError;
	}
	if (listing->follow_links() && S_ISLNK(entry_info.st_mode)) {
	// Check to see if we are in a loop created by a symbolic link.
	LinkList current_link = { entry_info.st_dev,
	entry_info.st_ino,
	link_ };
	LinkList* previous = link_;
	while (previous != NULL) {
	if ((previous->dev == current_link.dev) &&
	(previous->ino == current_link.ino)) {
	// Report the looping link as a link, rather than following it.
	return kListLink;
	}
	previous = previous->next;
	}
	stat_success = TEMP_FAILURE_RETRY(
	stat64(listing->path_buffer().AsString(), &entry_info));
	if (stat_success == -1) {
	// Report a broken link as a link, even if follow_links is true.
	return kListLink;
	}
	if (S_ISDIR(entry_info.st_mode)) {
	// Recurse into the subdirectory with current_link added to the
	// linked list of seen file system links.
	link_ = new LinkList(current_link);
	if ((strcmp(entry.d_name, ".") == 0) \|\|
	(strcmp(entry.d_name, "..") == 0)) {
	return Next(listing);
	}
	return kListDirectory;
	}
	}
	if (S_ISDIR(entry_info.st_mode)) {
	if ((strcmp(entry.d_name, ".") == 0) \|\|
	(strcmp(entry.d_name, "..") == 0)) {
	return Next(listing);
	}
	return kListDirectory;
	} else if (S_ISREG(entry_info.st_mode)) {
	return kListFile;
	} else if (S_ISLNK(entry_info.st_mode)) {
	return kListLink;
	}
	}

	default:
	break;
	}
	}
	done_ = true;

	if (status != 0) {
	errno = status;
	return kListError;
	}

	return kListDone;
	}


	DirectoryListingEntry::~DirectoryListingEntry() {
	ResetLink();
	if (lister_ != 0) {
	VOID_NO_RETRY_EXPECTED(closedir(reinterpret_cast<DIR*>(lister_)));
	}
	}


	void DirectoryListingEntry::ResetLink() {
	if ((link_ != NULL) && ((parent_ == NULL) \|\| (parent_->link_ != link_))) {
	delete link_;
	link_ = NULL;
	}
	if (parent_ != NULL) {
	link_ = parent_->link_;
	}
	}


	static bool DeleteRecursively(PathBuffer* path);


	static bool DeleteFile(char* file_name,
	PathBuffer* path) {
	return path->Add(file_name) &&
	(NO_RETRY_EXPECTED(unlink(path->AsString())) == 0);
	}


	static bool DeleteDir(char* dir_name,
	PathBuffer* path) {
	if ((strcmp(dir_name, ".") == 0) \|\| (strcmp(dir_name, "..") == 0)) {
	return true;
	}
	return path->Add(dir_name) && DeleteRecursively(path);
	}


	static bool DeleteRecursively(PathBuffer* path) {
	// Do not recurse into links for deletion. Instead delete the link.
	// If it's a file, delete it.
	struct stat64 st;
	if (TEMP_FAILURE_RETRY(lstat64(path->AsString(), &st)) == -1) {
	return false;
	} else if (S_ISREG(st.st_mode) \|\| S_ISLNK(st.st_mode)) {
	return (NO_RETRY_EXPECTED(unlink(path->AsString())) == 0);
	}

	if (!path->Add(File::PathSeparator())) {
	return false;
	}

	// Not a link. Attempt to open as a directory and recurse into the
	// directory.
	DIR* dir_pointer;
	do {
	dir_pointer = opendir(path->AsString());
	} while ((dir_pointer == NULL) && (errno == EINTR));
	if (dir_pointer == NULL) {
	return false;
	}

	// Iterate the directory and delete all files and directories.
	int path_length = path->length();
	dirent entry;
	dirent* result;
	while (NO_RETRY_EXPECTED(readdir_r(dir_pointer, &entry, &result)) == 0) {
	if (result == NULL) {
	// End of directory.
	return (NO_RETRY_EXPECTED(closedir(dir_pointer)) == 0) &&
	(NO_RETRY_EXPECTED(remove(path->AsString())) == 0);
	}
	bool ok = false;
	switch (entry.d_type) {
	case DT_DIR:
	ok = DeleteDir(entry.d_name, path);
	break;
	case DT_REG:
	case DT_LNK:
	// Treat all links as files. This will delete the link which
	// is what we want no matter if the link target is a file or a
	// directory.
	ok = DeleteFile(entry.d_name, path);
	break;
	case DT_UNKNOWN: {
	if (!path->Add(entry.d_name)) {
	break;
	}
	// On some file systems the entry type is not determined by
	// readdir_r. For those we use lstat to determine the entry
	// type.
	struct stat64 entry_info;
	if (TEMP_FAILURE_RETRY(lstat64(path->AsString(), &entry_info)) == -1) {
	break;
	}
	path->Reset(path_length);
	if (S_ISDIR(entry_info.st_mode)) {
	ok = DeleteDir(entry.d_name, path);
	} else if (S_ISREG(entry_info.st_mode) \|\| S_ISLNK(entry_info.st_mode)) {
	// Treat links as files. This will delete the link which is
	// what we want no matter if the link target is a file or a
	// directory.
	ok = DeleteFile(entry.d_name, path);
	}
	break;
	}
	default:
	break;
	}
	if (!ok) {
	break;
	}
	path->Reset(path_length);
	}
	// Only happens if an error.
	ASSERT(errno != 0);
	int err = errno;
	VOID_NO_RETRY_EXPECTED(closedir(dir_pointer));
	errno = err;
	return false;
	}


	Directory::ExistsResult Directory::Exists(const char* dir_name) {
	struct stat64 entry_info;
	int success = TEMP_FAILURE_RETRY(stat64(dir_name, &entry_info));
	if (success == 0) {
	if (S_ISDIR(entry_info.st_mode)) {
	return EXISTS;
	} else {
	return DOES_NOT_EXIST;
	}
	} else {
	if ((errno == EACCES) \|\|
	(errno == EBADF) \|\|
	(errno == EFAULT) \|\|
	(errno == ENOMEM) \|\|
	(errno == EOVERFLOW)) {
	// Search permissions denied for one of the directories in the
	// path or a low level error occured. We do not know if the
	// directory exists.
	return UNKNOWN;
	}
	ASSERT((errno == ELOOP) \|\|
	(errno == ENAMETOOLONG) \|\|
	(errno == ENOENT) \|\|
	(errno == ENOTDIR));
	return DOES_NOT_EXIST;
	}
	}


	char* Directory::CurrentNoScope() {
	return getcwd(NULL, 0);
	}


	const char* Directory::Current() {
	char buffer[PATH_MAX];
	if (getcwd(buffer, PATH_MAX) == NULL) {
	return NULL;
	}
	return DartUtils::ScopedCopyCString(buffer);
	}


	bool Directory::SetCurrent(const char* path) {
	return (NO_RETRY_EXPECTED(chdir(path)) == 0);
	}


	bool Directory::Create(const char* dir_name) {
	// Create the directory with the permissions specified by the
	// process umask.
	int result = NO_RETRY_EXPECTED(mkdir(dir_name, 0777));
	// If the directory already exists, treat it as a success.
	if ((result == -1) && (errno == EEXIST)) {
	return (Exists(dir_name) == EXISTS);
	}
	return (result == 0);
	}


	const char* Directory::SystemTemp() {
	PathBuffer path;
	const char* temp_dir = getenv("TMPDIR");
	if (temp_dir == NULL) {
	temp_dir = getenv("TMP");
	}
	if (temp_dir == NULL) {
	temp_dir = "/tmp";
	}
	if (!path.Add(temp_dir)) {
	return NULL;
	}

	// Remove any trailing slash.
	char* result = path.AsString();
	int length = strlen(result);
	if ((length > 1) && (result[length - 1] == '/')) {
	result[length - 1] = '\0';
	}
	return path.AsScopedString();
	}


	const char* Directory::CreateTemp(const char* prefix) {
	// Returns a new, unused directory name, adding characters to the end
	// of prefix. Creates the directory with the permissions specified
	// by the process umask.
	// The return value is Dart_ScopeAllocated.
	PathBuffer path;
	if (!path.Add(prefix)) {
	return NULL;
	}
	if (!path.Add("XXXXXX")) {
	// Pattern has overflowed.
	return NULL;
	}
	char* result;
	do {
	result = mkdtemp(path.AsString());
	} while ((result == NULL) && (errno == EINTR));
	if (result == NULL) {
	return NULL;
	}
	return path.AsScopedString();
	}


	bool Directory::Delete(const char* dir_name, bool recursive) {
	if (!recursive) {
	if ((File::GetType(dir_name, false) == File::kIsLink) &&
	(File::GetType(dir_name, true) == File::kIsDirectory)) {
	return NO_RETRY_EXPECTED(unlink(dir_name)) == 0;
	}
	return NO_RETRY_EXPECTED(rmdir(dir_name)) == 0;
	} else {
	PathBuffer path;
	if (!path.Add(dir_name)) {
	return false;
	}
	return DeleteRecursively(&path);
	}
	}


	bool Directory::Rename(const char* path, const char* new_path) {
	ExistsResult exists = Exists(path);
	if (exists != EXISTS) {
	return false;
	}
	return (NO_RETRY_EXPECTED(rename(path, new_path)) == 0);
	}

	} // namespace bin
	} // namespace dart

	#endif // defined(TARGET_OS_LINUX)