redi::basic_rpstream

Section: C Library Functions (3) Updated: 25 Oct 2005 Local index Up

NAME

redi::basic_rpstream - template for Restricted PStreams.

SYNOPSIS

Inherits redi::pstream_common< CharT, Traits >< CharT, Traits >, and redi::pstreams.

Public Types

typedef pbase_type::pmode pmode
Type used to specify how to connect to the process.
typedef pbase_type::argv_type argv_type
Type used to hold the arguments for a command.
typedef int fd_type
Type used for file descriptors.

Public Member Functions

basic_rpstream ()
Default constructor, creates an uninitialised stream.
basic_rpstream (const std::string &command, pmode mode=pstdout|pstdin)
Constructor that initialises the stream by starting a process.
basic_rpstream (const std::string &file, const argv_type &argv, pmode mode=pstdout|pstdin)
Constructor that initialises the stream by starting a process.
~basic_rpstream ()
Destructor.
void open (const std::string &command, pmode mode=pstdout|pstdin)
Start a process.
void open (const std::string &file, const argv_type &argv, pmode mode=pstdout|pstdin)
Start a process.
istream_type & out ()
Obtain a reference to the istream that reads the process' stdout.
istream_type & err ()
Obtain a reference to the istream that reads the process' stderr.

Static Public Attributes

static const pmode pstdin = std::ios_base::out
Write to stdin.
static const pmode pstdout = std::ios_base::in
Read from stdout.
static const pmode pstderr = std::ios_base::app
Read from stderr.

Protected Types

enum { bufsz = 32 }

enum { pbsz = 2 }

Detailed Description

template<typename CharT, typename Traits = std::char_traits<CharT>> class redi::basic_rpstream< CharT, Traits >

template for Restricted PStreams.

Writing to an rpstream opened with pmode pstdin writes to the standard input of the command. It is not possible to read directly from an rpstream object, to use an rpstream as in istream you must call either basic_rpstream::out() or basic_rpstream::err(). This is to prevent accidental reads from the wrong input source. If the rpstream was not opened with pmode pstderr then the class cannot read the process' stderr, and basic_rpstream::err() will return an istream that reads from the process' stdout, and vice versa. Reading from an rpstream opened with pmode pstdout and/or pstderr reads the command's standard output and/or standard error. Any of the process' stdin, stdout or stderr that is not connected to the pstream (as specified by the pmode) will be the same as the process that created the pstream object, unless altered by the command itself.

Constructor & Destructor Documentation

template<typename CharT, typename Traits = std::char_traits<CharT>> redi::basic_rpstream< CharT, Traits >::basic_rpstream (const std::string & command, pmode mode = pstdout|pstdin) [inline]

Constructor that initialises the stream by starting a process.

Initialises the stream buffer by calling do_open() with the supplied arguments.

Parameters:

: command a string containing a shell command.
mode the I/O mode to use when opening the pipe.

See also:

: do_open(const std::string&, pmode)

template<typename CharT, typename Traits = std::char_traits<CharT>> redi::basic_rpstream< CharT, Traits >::basic_rpstream (const std::string & file, const argv_type & argv, pmode mode = pstdout|pstdin) [inline]

Constructor that initialises the stream by starting a process.

Initialises the stream buffer by calling do_open() with the supplied arguments.

Parameters:

: file a string containing the pathname of a program to execute.
argv a vector of argument strings passed to the new program.
mode the I/O mode to use when opening the pipe.

See also:

: do_open(const std::string&, const argv_type&, pmode)

Member Function Documentation

template<typename CharT, typename Traits = std::char_traits<CharT>> istream_type& redi::basic_rpstream< CharT, Traits >::err () [inline]

Obtain a reference to the istream that reads the process' stderr.

Returns:

: *this

template<typename CharT, typename Traits = std::char_traits<CharT>> void redi::basic_rpstream< CharT, Traits >::open (const std::string & file, const argv_type & argv, pmode mode = pstdout|pstdin) [inline]

Start a process.

Calls do_open( file , argv , mode ).

Parameters:

: file a string containing the pathname of a program to execute.
argv a vector of argument strings passed to the new program.
mode the I/O mode to use when opening the pipe.

See also: