Dv::Util::iopstream Class Reference

Start a process with its standard input/output connected to an iostream. More...

#include <iopstream.h>

Inheritance diagram for Dv::Util::iopstream:

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Collaboration diagram for Dv::Util::iopstream:

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List of all members.

Public Member Functions
	iopstream (const std::string &command, unsigned int min_debug_level=1) throw (std::runtime_error)
	Create an input/output stream from/to a process running command.
int	close () throw (std::runtime_error)
	Close stream.
	~iopstream () throw (std::runtime_error)
	Destructor.
Private Member Functions
void	start () throw (std::runtime_error)
	Start up a new process.

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Detailed Description

Start a process with its standard input/output connected to an iostream.

Definition at line 16 of file iopstream.h.

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Constructor & Destructor Documentation

Dv::Util::iopstream::iopstream	(	const std::string &	command,
		unsigned int	min_debug_level = 1
	)			throw (std::runtime_error)

Create an input/output stream from/to a process running command.

The process is created using execl with argument

 /bin/sh -c command
 

Data written to the stream will appear on the standard input of the process. The standard output of the process can be read from the stream.

Parameters:

	command	which will be run using /bin/sh -c command
	min_debug_level	for when the object is connected to a debug master

See also:

Dv::Debugable

Exceptions:

std::runtime_error

if anything goes wrong.

Dv::Util::iopstream::~iopstream

(

)

throw (std::runtime_error)

Destructor.

Exceptions:

std::runtime_error

if anything goes wrong.

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Member Function Documentation

int Dv::Util::iopstream::close

(

)

throw (std::runtime_error)

Close stream.

Wait for command to finish, then return its exit status. After a close, the stream is unusable.

Returns:

exit status of command as returned by main().

Warning:

A negative exit status gets converted to a positive number, i.e. -1 becomes 255.

Exceptions:

std::runtime_error

if command did not exit normally or any other problem.

void Dv::Util::iopstream::start

(

)

throw (std::runtime_error) [private]

Start up a new process.

Returns:

pid iff the process is running

0 in the child process if the process is not running a command

Exceptions:

	std::runtime_error	if fork() failed.
	std::runtime_error	if execl() failed.
	std::logic_error	if the process is already running

• If the process command is not empty, it will be executed using

     /bin/sh -c exec command
  

  Example:

     Dv::Util::Process proc("ping www.bla.com");
     proc.start();
  

• If the process command is empty, a fork() will be executed and the function will return false in the child process. This supports code such as the following.

     Dv::Util::Process p;
     if (! p.start())
       return f(...); // in the child
     p.wait(); // in the parent
  

  See also:

  Dv::Util::Process::Process

Reimplemented from Dv::Util::Process.

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

• iopstream.h