ucommon::shell::iobuf Class Reference

Process pipe with I/O buffering. More...

#include <shell.h>

Inheritance diagram for ucommon::shell::iobuf:

Collaboration diagram for ucommon::shell::iobuf:

Public Member Functions
void	cancel (void)
	Terminate child process.
void	close (void)
	Close the i/o buffer.
	iobuf (size_t size=0)
	Construct an i/o buffer.
	iobuf (char *path, char **argv, pmode_t mode, size_t size=512, char **env=((void *) 0))
	Construct an i/o buffer for a child process.
void	open (char *path, char **argv, pmode_t mode, size_t size=512, char **env=((void *) 0))
	Open the i/o buffer attached to a child process.
	~iobuf ()
	Destroy i/o buffer.
Public Member Functions inherited from ucommon::BufferProtocol
int	_getch (void)
	Get a character from the buffer.
int	_putch (int ch)
	Put a character into the buffer.
bool	eof (void)
	Check if at end of input.
int	err (void)
bool	flush (void)
	Flush buffered memory to physical I/O.
size_t	get (char *address, size_t count)
	Get memory from the buffer.
size_t	getline (char *string, size_t size)
	Get text as a line of input from the buffer.
size_t	getline (string &buffer)
	Get a string as a line of input from the buffer.
bool	is_input (void)
	See if input active.
bool	is_open (void)
	See if buffer open.
bool	is_output (void)
	See if output active.
bool	is_pending (void)
	See if pending input.
	operator bool ()
	See if buffer open.
bool	operator! ()
	See if buffer closed.
size_t	printf (const char *format,...)
	Print formatted string to the buffer.
void	purge (void)
	Purge any pending input or output buffer data.
size_t	put (const char *address, size_t count=0)
	Put memory into the buffer.
size_t	putline (const char *string)
	Put a string as a line of output to the buffer.
void	reset (void)
	Reset input buffer state.
void	seteof (void)
	Set eof flag.
Public Member Functions inherited from ucommon::CharacterProtocol
int	get (void)
	Get the next character.
int	put (int code)
	Put the next character.

Protected Member Functions
virtual void	_clear (void)
	Method to clear low level i/o error.
virtual int	_err (void)
virtual size_t	_pull (char *address, size_t size)
	Method to pull buffer from physical i/o (read).
virtual size_t	_push (char *address, size_t size)
Protected Member Functions inherited from ucommon::BufferProtocol
virtual bool	_blocking (void)
	Return true if blocking.
virtual int	_err (void) const =0
	Method to get low level i/o error.
virtual bool	_flush (void)
	Flush buffer to physical i/o.
virtual bool	_pending (void)
	Check if data is pending.
virtual size_t	_push (const char *address, size_t size)=0
	Method to push buffer into physical i/o (write).
void	allocate (size_t size, type_t access=BUF_RDWR)
	Allocate I/O buffer(s) of specified size.
	BufferProtocol ()
	Construct an empty (unallocated) buffer.
	BufferProtocol (size_t size, type_t access=BUF_RDWR)
	Construct a buffer of pre-allocated size and access type.
char *	gather (size_t size)
	Gather returns a pointer to contiguous input of specified size.
void	release (void)
	Release (free) buffer memory.
char *	request (size_t size)
	Request workspace in output buffer.
void	seteol (const char *string)
	Set end of line marker.
size_t	unread (void)
	Get current input position.
size_t	unsaved (void)
	Get current output position.
virtual	~BufferProtocol ()
	Destroy object by releasing buffer memory.

Protected Attributes
int	ioerror
Protected Attributes inherited from ucommon::BufferProtocol
const char *	format

Friends
class	shell

Additional Inherited Members
Public Types inherited from ucommon::BufferProtocol
enum	type_t { BUF_RD, BUF_WR, BUF_RDWR }

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Detailed Description

Process pipe with I/O buffering.

This allows the creation and management of a shell pipe with buffered I/O support. This also offers a common class to manage stdio sessions generically in the child process.

Author:

David Sugar dyfet.nosp@m.@gnu.nosp@m.telep.nosp@m.hony.nosp@m..org

Definition at line 229 of file shell.h.

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Constructor & Destructor Documentation

ucommon::shell::iobuf::iobuf

(

size_t

size = 0

)

Construct an i/o buffer.

If a non-zero size is specified, then the object is attached to the process's stdin & stdout. Otherwise an un-opened object is created.

ucommon::shell::iobuf::iobuf	(	char *	path,
		char **	argv,
		pmode_t	mode,
		size_t	size = 512,
		char **	env = ((void *) 0)
	)

Construct an i/o buffer for a child process.

This is used to create a child process directly when the object is made. It essentially is the same as the open() method.

Parameters:

path	of program to execute, if filename uses $PATH.
argv	to pass to child process.
mode	of pipe, rdonly, wronly, or rdwr.
size	of buffering, and atomic pipe size if settable.
env	that may be passed to child process.

ucommon::shell::iobuf::~iobuf

(

)

Destroy i/o buffer.

This may cancel and block waiting for a child process to terminate.

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Member Function Documentation

virtual size_t ucommon::shell::iobuf::_pull ( char *  address, size_t  size  )

protectedvirtual

Method to pull buffer from physical i/o (read).

The address is passed to this virtual since it is hidden as private.

Parameters:

address	of buffer to pull data into.
size	of buffer area being pulled..

Returns:

number of read written, 0 on error or end of data.

Implements ucommon::BufferProtocol.

void ucommon::shell::iobuf::cancel

(

void

)

Terminate child process.

This also waits for the child process to exit and then closes buffers.

Reimplemented from ucommon::shell::pipeio.

void ucommon::shell::iobuf::close

(

void

)

Close the i/o buffer.

If attached to a child process it will wait for the child to exit.

void ucommon::shell::iobuf::open	(	char *	path,
		char **	argv,
		pmode_t	mode,
		size_t	size = 512,
		char **	env = ((void *) 0)
	)

Open the i/o buffer attached to a child process.

Parameters:

path	of program to execute, if filename uses $PATH.
argv	to pass to child process.
mode	of pipe, rdonly, wronly, or rdwr.
size	of buffering, and atomic pipe size if settable.
env	that may be passed to child process.

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

• ucommon/shell.h