jFStreamUtil.h File Reference

#include "jTypes.h"
#include <fstream>

Include dependency graph for jFStreamUtil.h:

This graph shows which files directly or indirectly include this file:

Functions
void	JReadFile (const JString &fileName, JString *str)
void	JReadFile (std::ifstream &input, JString *str)
void	JReadFile (std::fstream &input, JString *str)
JSize	JGetFStreamLength (std::ifstream &theStream)
JSize	JGetFStreamLength (std::fstream &theStream)
std::fstream *	JSetFStreamLength (const char *fileName, std::fstream &originalStream, const JSize newLength, const JFStreamOpenMode io_mode)
std::fstream *	JSetFStreamLength (const JString &fileName, std::fstream &originalStream, const JSize newLength, const JFStreamOpenMode io_mode)
bool	JConvertToStream (const int input, std::ifstream *input2, JString *tempFullName, const bool closeInput=true)

Function Documentation

JConvertToStream()

bool JConvertToStream	(	const int	input,
		std::ifstream *	input2,
		JString *	tempFullName,
		const bool	closeInput
	)

Convert the data from the given file descriptor into an std::ifstream. The location of the file is returned in tempFullName.

This would be unnecessary if libstdc++ provided a stream wrapper for arbitrary file descriptors.

JGetFStreamLength() [1/2]

JSize JGetFStreamLength

(

std::fstream &

theStream

)

JGetFStreamLength() [2/2]

JSize JGetFStreamLength

(

std::ifstream &

theStream

)

Returns the length of the file associated with theStream.

JReadFile() [1/3]

void JReadFile	(	const JString &	fileName,
		JString *	str
	)

Read characters from the std::fstream until the end of the file is reached. These functions takes a JString* because the contents of the file could be very large, and returning a JString requires twice as much memory because of the copy constructor.

These are equivalent to JReadAll() in jStreamUtil.h, except that they are optimized to work with file streams.

JReadFile() [2/3]

void JReadFile	(	std::fstream &	input,
		JString *	str
	)

JReadFile() [3/3]

void JReadFile	(	std::ifstream &	input,
		JString *	str
	)

JSetFStreamLength() [1/2]

std::fstream * JSetFStreamLength	(	const char *	fileName,
		std::fstream &	originalStream,
		const JSize	newLength,
		const JFStreamOpenMode	io_mode
	)

JSetFStreamLength() [2/2]

std::fstream * JSetFStreamLength	(	const JString &	fileName,
		std::fstream &	originalStream,
		const JSize	newLength,
		const JFStreamOpenMode	io_mode
	)

Sets the length of the file associated with originalStream.

The only efficient way is to use ftruncate(), which requires a file descriptor. Since we can't get this from the stream, we require the file name. Once we operate on the descriptor, the stream will be hopelessly confused, so we have to close it first. This is why we return a jnew one afterwards.

The caller is responsible for deleting originalStream.