ucc::shell::pipeio Class Reference

A class to control a process that is piped. More...

#include <shell.h>

Inheritance diagram for ucc::shell::pipeio:

[legend]

Protected Member Functions
int	cancel (void)
	Signal termination and wait for child process to exit.
	pipeio ()
	Construct an empty initialized pipe for use.
size_t	read (void *address, size_t size)
	Read input from child process.
int	spawn (const char *path, char **argv, pmode_t mode, size_t size=512, char **env=NULL)
	Spawn and attach child process I/O through piping.
int	wait (void)
	Wait for child process to exit.
size_t	write (const void *address, size_t size)
	Write to the child process.
Protected Attributes
fd_t	input
fd_t	output
int	perror
pid_t	pid
int	presult
Friends
class	shell

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Detailed Description

A class to control a process that is piped.

This holds the active file descriptors for the pipe as well as the process id. Basic I/O methods are provided to send and receive data with the piped child process. This may be used by itself with various shell methods as a pipe_t, or to construct piped objects such as iobuf.

Author:

David Sugar <dyfet@gnutelephony.org>

Definition at line 111 of file shell.h.

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Member Function Documentation

int ucc::shell::pipeio::cancel

(

void

)

[protected]

Signal termination and wait for child process to exit.

When it does all piping is closed.

Returns:

process exit code or -1 if error.

Reimplemented in ucc::shell::iobuf.

size_t ucc::shell::pipeio::read	(	void *	address,
		size_t	size
	)			[protected]

Read input from child process.

If there is an error, the result is 0 and perror holds the error code. If an error already happened no further data will be read.

Parameters:

	address	to store input.
	size	of input to read.

Returns:

number of bytes actually read.

int ucc::shell::pipeio::spawn	(	const char *	path,
		char **	argv,
		pmode_t	mode,
		size_t	size = 512,
		char **	env = NULL
	)			[protected]

Spawn and attach child process I/O through piping.

Stderr is left attached to the console.

Parameters:

	path	of program to execute. If simple file, $PATH is used.
	argv	to pass to child process.
	mode	of pipe operation; rdonly, wronly, or rdwr.
	size	of atomic pipe buffer if setable.
	env	that may optionally be given to the child process.

int ucc::shell::pipeio::wait

(

void

)

[protected]

Wait for child process to exit.

When it does, close all piping.

Returns:

process exit code or -1 if error.

size_t ucc::shell::pipeio::write	(	const void *	address,
		size_t	size
	)			[protected]

Write to the child process.

If there is an error, the result is 0 and perror holds the error code. If an error already happened no further data will be written.

Parameters:

	address	to write data from.
	size	of data to write.

Returns:

number of bytes actually written.

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

• ucommon/shell.h