The FileUtils class provides static functions to easily access and handle files and the file system. More...

#include <FileUtils.h>

Static Public Member Functions
static bool	read (const String &fname, String &contents)
	Reads a whole file into a String. More...

static ssize_t	read (int fd, void *vptr, size_t n)
	Reads data from a file descriptor into a buffer. More...

static ssize_t	pread (int fd, void *vptr, size_t n, off_t offset)
	Reads positional data from a file descriptor into a buffer. More...

static ssize_t	write (const String &fname, const std::string &contents)
	Writes a String buffer to a file; the file is overwritten if it already exists. More...

static ssize_t	write (int fd, const void *vptr, size_t n)
	Writes a memory buffer to a file descriptor. More...

static ssize_t	write (int fd, const std::string &str)
	Writes a string to a file descriptor. More...

static ssize_t	writev (int fd, const struct iovec *vector, int count)
	Atomically writes data from multiple buffers to a file descriptor. More...

static ssize_t	sendto (int fd, const void vptr, size_t n, const sockaddr to, socklen_t tolen)
	Sends data through a network connection; if the socket is TCP then the address is ignored. More...

static ssize_t	send (int fd, const void *vptr, size_t n)
	Sends data through a network connection. More...

static ssize_t	recvfrom (int fd, void vptr, size_t n, struct sockaddr from, socklen_t *fromlen)
	Receives data from a network connection and returns the sender's address. More...

static ssize_t	recv (int fd, void *vptr, size_t n)
	Receives data from a network connection. More...

static bool	set_flags (int fd, int flags)
	Sets fcntl flags of a socket. More...

static char *	file_to_buffer (const String &fname, off_t *lenp)
	Reads a full file into a new buffer; the buffer is allocated with operator new[], and the caller has to delete[] it. More...

static String	file_to_string (const String &fname)
	Reads a full file into a String. More...

static void *	mmap (const String &fname, off_t *lenp)
	Maps a full file into memory using mmap; the mapping will be released when the application terminates (there's currently no munmap) More...

static bool	mkdirs (const String &dirname)
	Creates a directory (with all parent directories, if required) More...

static bool	exists (const String &fname)
	Checks if a file or directory exists. More...

static bool	unlink (const String &fname)
	Unlinks (deletes) a file or directory. More...

static bool	rename (const String &oldpath, const String &newpath)
	Renames a file or directory. More...

static uint64_t	size (const String &fname)
	Returns the size of a file (0 on error) More...

static off_t	length (const String &fname)
	Returns the size of a file (-1 on error) More...

static void	add_trailing_slash (String &path)
	Adds a trailing slash to a path. More...

static bool	expand_tilde (String &fname)
	Expands a leading tilde character in a filename. More...

static void	readdir (const String &dirname, const String &fname_regex, std::vector< struct dirent > &listing)
	Reads all directory entries, applies a regular expression and returns those which match. More...

Static Public Attributes
static std::mutex	ms_mutex
	Mutex for protecting thread-unsafe glibc library function calls. More...

Detailed Description

The FileUtils class provides static functions to easily access and handle files and the file system.

Definition at line 51 of file FileUtils.h.

Member Function Documentation

void FileUtils::add_trailing_slash ( String & path )

static

Adds a trailing slash to a path.

Definition at line 466 of file FileUtils.cc.

bool FileUtils::exists ( const String & fname )

static

Checks if a file or directory exists.

Returns: true if the file or directory exists, otherwise false

Definition at line 420 of file FileUtils.cc.

bool FileUtils::expand_tilde ( String & fname )

static

Expands a leading tilde character in a filename.

Examples:

~chris/foo -> /home/chris/foo ~/foo -> /home/$USER/foo

Returns: true on success, false on error

Definition at line 472 of file FileUtils.cc.

char * FileUtils::file_to_buffer	(	const String &	fname,
		off_t *	lenp
	)

static

Reads a full file into a new buffer; the buffer is allocated with operator new[], and the caller has to delete[] it.

Parameters

fname	The file name
lenp	Receives the length of the buffer, in bytes

Returns: A pointer allocated with new[]; needs to be delete[]d by the caller. Returns 0 on error (sets errno)

Definition at line 282 of file FileUtils.cc.

String FileUtils::file_to_string ( const String & fname )

static

Reads a full file into a String.

Parameters

fname The file name

Returns: A string with the data, or an empty string on error (sets errno)

Definition at line 333 of file FileUtils.cc.

off_t FileUtils::length ( const String & fname )

static

Returns the size of a file (-1 on error)

Parameters

fname The path of the file

Returns: The file size (in bytes) or -1 on error (sets errno)

Definition at line 458 of file FileUtils.cc.

bool FileUtils::mkdirs ( const String & dirname )

static

Creates a directory (with all parent directories, if required)

Parameters

dirname The directory name to create

Returns: true on success, otherwise falls (sets errno)

Definition at line 366 of file FileUtils.cc.

void * FileUtils::mmap	(	const String &	fname,
		off_t *	lenp
	)

static

Maps a full file into memory using mmap; the mapping will be released when the application terminates (there's currently no munmap)

Parameters

fname	The file name
lenp	Receives the length of the buffer, in bytes

Returns: A pointer to the mapped data

Definition at line 343 of file FileUtils.cc.

ssize_t FileUtils::pread	(	int	fd,
		void *	vptr,
		size_t	n,
		off_t	offset
	)

static

Reads positional data from a file descriptor into a buffer.

Parameters

fd	The open file descriptor
vptr	Pointer to the memory buffer
n	Maximum size to read, in bytes
offset	The start offset in the file

Returns: The number of bytes read, or -1 on error

Definition at line 97 of file FileUtils.cc.

bool FileUtils::read	(	const String &	fname,
		String &	contents
	)

static

Reads a whole file into a String.

Parameters

fname	The file name
contents	A reference to a String which will receive the data

Returns: true on success, false on error

Definition at line 59 of file FileUtils.cc.

ssize_t FileUtils::read	(	int	fd,
		void *	vptr,
		size_t	n
	)

static

Reads data from a file descriptor into a buffer.

Parameters

fd	The open file descriptor
vptr	Pointer to the memory buffer
n	Maximum size to read, in bytes

Returns: The number of bytes read, or -1 on error

Definition at line 71 of file FileUtils.cc.

void FileUtils::readdir	(	const String &	dirname,
		const String &	fname_regex,
		std::vector< struct dirent > &	listing
	)

static

Reads all directory entries, applies a regular expression and returns those which match.

This function will call HT_FATAL on error!

Parameters

dirname	The directory name
fname_regex	The regular expression; can be empty
listing	Vector with the results

Definition at line 511 of file FileUtils.cc.

ssize_t FileUtils::recv	(	int	fd,
		void *	vptr,
		size_t	n
	)

static

Receives data from a network connection.

Parameters

fd	Open file handle/socket descriptor
vptr	Pointer to the memory buffer which receives the data
n	Capacity of the memory buffer, in bytes

Returns: Total number of bytes received, or -1 on error, 0 on eof

Definition at line 242 of file FileUtils.cc.

ssize_t FileUtils::recvfrom	(	int	fd,
		void *	vptr,
		size_t	n,
		struct sockaddr *	from,
		socklen_t *	fromlen
	)

static

Receives data from a network connection and returns the sender's address.

Parameters

fd	Open file handle/socket descriptor
vptr	Pointer to the memory buffer which receives the data
n	Capacity of the memory buffer, in bytes
from	The sender's address
fromlen	Length of the sockaddr structure

Returns: Total number of bytes received, or -1 on error, 0 on eof

Definition at line 227 of file FileUtils.cc.

bool FileUtils::rename	(	const String &	oldpath,
		const String &	newpath
	)

static

Renames a file or directory.

Parameters

oldpath	The path of the file (or directory) to rename
newpath	The new filename

Returns: true on success, otherwise false (sets errno)

Definition at line 438 of file FileUtils.cc.

ssize_t FileUtils::send	(	int	fd,
		const void *	vptr,
		size_t	n
	)

static

Sends data through a network connection.

Parameters

fd	Open file handle/socket descriptor
vptr	Pointer to the memory buffer which is sent
n	Size of the memory buffer, in bytes

Returns: Total number of bytes sent, or -1 on error

Definition at line 203 of file FileUtils.cc.

ssize_t FileUtils::sendto	(	int	fd,
		const void *	vptr,
		size_t	n,
		const sockaddr *	to,
		socklen_t	tolen
	)

static

Sends data through a network connection; if the socket is TCP then the address is ignored.

For UDP sockets the address structure specifies the recipient.

Parameters

fd	Open file handle/socket descriptor
vptr	Pointer to the memory buffer which is sent
n	Size of the memory buffer, in bytes
to	The recipient's address (only UDP; ignored for TCP sockets)
tolen	Length of the sockaddr structure

Returns: Total number of bytes sent, or -1 on error

Definition at line 178 of file FileUtils.cc.

bool FileUtils::set_flags	(	int	fd,
		int	flags
	)

static

Sets fcntl flags of a socket.

Parameters

fd	Open file handle/socket descriptor
flags	The fcntl flags; will be ORed with the existing flags

Returns: true on success, otherwise false (sets errno)

Definition at line 256 of file FileUtils.cc.

uint64_t FileUtils::size ( const String & fname )

static

Returns the size of a file (0 on error)

Parameters

fname The path of the file

Returns: The file size (in bytes) or 0 on error (sets errno)

Definition at line 450 of file FileUtils.cc.

bool FileUtils::unlink ( const String & fname )

static

Unlinks (deletes) a file or directory.

Returns: true on success, otherwise false (sets errno)

Definition at line 427 of file FileUtils.cc.

ssize_t FileUtils::write	(	const String &	fname,
		const std::string &	contents
	)

static

Writes a String buffer to a file; the file is overwritten if it already exists.

Parameters

fname	Path of the file that is (over)written
contents	The string contents that are written to the file

Returns: Number of bytes written, or -1 on error

Definition at line 124 of file FileUtils.cc.

ssize_t FileUtils::write	(	int	fd,
		const void *	vptr,
		size_t	n
	)

static

Writes a memory buffer to a file descriptor.

Parameters

fd	Open file handle
vptr	Pointer to the memory buffer
n	Size of the memory buffer, in bytes

Returns: Number of bytes written, or -1 on error

Definition at line 139 of file FileUtils.cc.

static ssize_t Hypertable::FileUtils::write	(	int	fd,
		const std::string &	str
	)

inlinestatic

Writes a string to a file descriptor.

Parameters

fd	Open file handle
str	String to write to file

Returns: Number of bytes written, or -1 on error

Definition at line 104 of file FileUtils.h.

ssize_t FileUtils::writev	(	int	fd,
		const struct iovec *	vector,
		int	count
	)

static

Atomically writes data from multiple buffers to a file descriptor.

struct iovec { void *iov_base; // Starting address size_t iov_len; // Number of bytes to transfer };

Parameters

fd	Open file handle
vector	An iovec array holding pointers to the data
count	Number of iovec structures in vector

Returns: Total number of bytes written, or -1 on error

Definition at line 162 of file FileUtils.cc.

Member Data Documentation

std::mutex FileUtils::ms_mutex

static

Mutex for protecting thread-unsafe glibc library function calls.

Definition at line 269 of file FileUtils.h.

The documentation for this class was generated from the following files:

/home/doug/src/hypertable/src/cc/Common/FileUtils.h
/home/doug/src/hypertable/src/cc/Common/FileUtils.cc

Static Public Member Functions

Static Public Attributes

Detailed Description

Member Function Documentation

Member Data Documentation