TSDuck Version 3.32-2780 (TSDuck - The MPEG Transport Stream Toolkit)
ts::ForkPipe Class Reference

Fork a process and create an optional pipe to its standard input. More...

Inheritance diagram for ts::ForkPipe:
Collaboration diagram for ts::ForkPipe:

Public Types

enum  InputMode {
  STDIN_PARENT,
  STDIN_PIPE,
  STDIN_NONE
}
 How to standard input in the created process. More...
 
enum  OutputMode {
  KEEP_BOTH,
  STDOUT_ONLY,
  STDERR_ONLY,
  STDOUT_PIPE,
  STDOUTERR_PIPE
}
 How to merge standard output and standard error in the created process. More...
 
typedef std::basic_ostream< char > SuperClass
 Explicit reference to the public superclass.
 
enum  WaitMode {
  ASYNCHRONOUS,
  SYNCHRONOUS,
  EXIT_PROCESS
}
 How to wait for the created process when close() is invoked. More...
 

Public Member Functions

 ForkPipe ()
 Default constructor.
 
virtual ~ForkPipe () override
 Destructor.
 
void abortPipeReadWrite ()
 Abort any currenly input/output operation in the pipe. More...
 
bool close (Report &report)
 Close the pipe. More...
 
virtual bool endOfStream () override
 Check if the end of stream was reached. More...
 
bool getIgnoreAbort () const
 Get "ignore abort". More...
 
bool isBroken () const
 Check if the pipe was broken. More...
 
bool isOpen () const
 Check if the process is running and the pipe is open (when used). More...
 
bool isSynchronous () const
 Check if synchronous mode is active (ie. More...
 
bool open (const UString &command, WaitMode wait_mode, size_t buffer_size, Report &report, OutputMode out_mode, InputMode in_mode)
 Create the process, open the optional pipe. More...
 
virtual bool readStreamChunks (void *addr, size_t max_size, size_t chunk_size, size_t &ret_size, Report &report)
 Read chunks of data from the stream. More...
 
virtual bool readStreamComplete (void *addr, size_t max_size, size_t &ret_size, Report &report)
 Read complete data from the stream. More...
 
virtual bool readStreamPartial (void *addr, size_t max_size, size_t &ret_size, Report &report) override
 Read partial data from the stream. More...
 
void setIgnoreAbort (bool on)
 Set "ignore abort". More...
 
virtual bool writeStream (const void *addr, size_t size, size_t &written_size, Report &report) override
 Write data to the stream. More...
 

Static Public Member Functions

static bool Launch (const UString &command, Report &report, OutputMode out_mode=KEEP_BOTH, InputMode in_mode=STDIN_PARENT)
 This static method asynchronously launches a command, without pipe, without waiting for the completion of the command process. More...
 

Static Public Attributes

static constexpr size_t DEFAULT_STREAM_BUFFER_SIZE = 1024
 Default stream buffer size in bytes.
 

Protected Member Functions

virtual bool writeStreamBuffer (const void *addr, size_t size) override
 Write buffered data to underlying output devicen whatever it is. More...
 

Detailed Description

Fork a process and create an optional pipe to its standard input.

This class can be used as any output stream when the output is a pipe.

Member Enumeration Documentation

◆ WaitMode

How to wait for the created process when close() is invoked.

No pipe can be used with EXIT_PROCESS because there would be nobody on the other end of the pipe.

Enumerator
ASYNCHRONOUS 

Don't wait, close() will return immediately.

SYNCHRONOUS 

Wait for process completion during close().

EXIT_PROCESS 

Exit parent process during open(). UNIX: call exec(), Windows: call exit() after process creation.

◆ InputMode

How to standard input in the created process.

The pipe can be used either on input or output, but not both. So, STDIN_PIPE is also forbidden with output mode is either STDOUT_PIPE or STDOUTERR_PIPE.

Enumerator
STDIN_PARENT 

Keep same stdin as current (parent) process.

STDIN_PIPE 

Use the pipe as stdin.

STDIN_NONE 

No standard input (the null device in fact).

◆ OutputMode

How to merge standard output and standard error in the created process.

Enumerator
KEEP_BOTH 

Keep same stdout and stderr as current (parent) process.

STDOUT_ONLY 

Merge stderr into current stdout.

STDERR_ONLY 

Merge stdout into current stderr.

STDOUT_PIPE 

Use the pipe to receive stdout, keep same stderr as current (parent) process.

STDOUTERR_PIPE 

Use the pipe to receive a merge of stdout and stderr.

Member Function Documentation

◆ open()

bool ts::ForkPipe::open ( const UString command,
WaitMode  wait_mode,
size_t  buffer_size,
Report report,
OutputMode  out_mode,
InputMode  in_mode 
)

Create the process, open the optional pipe.

Parameters
[in]commandThe command to execute.
[in]wait_modeHow to wait for process termination in close().
[in]buffer_sizeThe pipe buffer size in bytes. Used on Windows only. Zero means default.
[in,out]reportWhere to report errors.
[in]out_modeHow to handle stdout and stderr.
[in]in_modeHow to handle stdin. Use the pipe by default. When set to KEEP_STDIN, no pipe is created.
Returns
True on success, false on error. Do not return on success when wait_mode is EXIT_PROCESS.

◆ close()

bool ts::ForkPipe::close ( Report report)

Close the pipe.

Optionally wait for process termination if wait_mode was SYNCHRONOUS on open().

Parameters
[in,out]reportWhere to report errors.
Returns
True on success, false on error.

◆ isOpen()

bool ts::ForkPipe::isOpen ( ) const
inline

Check if the process is running and the pipe is open (when used).

Returns
True if the process is running and the pipe is open.

◆ isBroken()

bool ts::ForkPipe::isBroken ( ) const
inline

Check if the pipe was broken.

Returns
True if was broken (unexpected process termination for instance).

◆ isSynchronous()

bool ts::ForkPipe::isSynchronous ( ) const
inline

Check if synchronous mode is active (ie.

will wait for process termination).

Returns
True if synchronous mode is active.

◆ setIgnoreAbort()

void ts::ForkPipe::setIgnoreAbort ( bool  on)
inline

Set "ignore abort".

Parameters
[in]onIf true and the process aborts, do not report error when writing data. when writing data.

◆ getIgnoreAbort()

bool ts::ForkPipe::getIgnoreAbort ( ) const
inline

Get "ignore abort".

Returns
True if, when the process aborts, do not report error when writing data.

◆ abortPipeReadWrite()

void ts::ForkPipe::abortPipeReadWrite ( )

Abort any currenly input/output operation in the pipe.

The pipe is left in a broken state and can be only closed.

◆ Launch()

static bool ts::ForkPipe::Launch ( const UString command,
Report report,
OutputMode  out_mode = KEEP_BOTH,
InputMode  in_mode = STDIN_PARENT 
)
static

This static method asynchronously launches a command, without pipe, without waiting for the completion of the command process.

Parameters
[in]commandThe command to execute.
[in,out]reportWhere to report errors.
[in]out_modeHow to handle stdout and stderr. Keep both by default. Output modes using pipes are forbidden.
[in]in_modeHow to handle stdin. Keep the parent input by default. Input modes using pipes are forbidden.
Returns
True on success, false on error.

◆ endOfStream()

virtual bool ts::ForkPipe::endOfStream ( )
overridevirtual

Check if the end of stream was reached.

Returns
True on end of stream, false otherwise.

Implements ts::AbstractReadStreamInterface.

◆ readStreamPartial()

virtual bool ts::ForkPipe::readStreamPartial ( void *  addr,
size_t  max_size,
size_t &  ret_size,
Report report 
)
overridevirtual

Read partial data from the stream.

Wait and read at least one byte. Don't try to read exactly max_size bytes. If ret_size is less than max_bytes, it is possible to read more.

Parameters
[out]addrAddress of the buffer for the incoming data.
[in]max_sizeMaximum size in bytes of the buffer.
[out]ret_sizeReturned input size in bytes. If zero, end of file has been reached or an error occurred.
[in,out]reportWhere to report errors.
Returns
True on success, false on error.

Implements ts::AbstractReadStreamInterface.

◆ writeStream()

virtual bool ts::ForkPipe::writeStream ( const void *  addr,
size_t  size,
size_t &  written_size,
Report report 
)
overridevirtual

Write data to the stream.

All bytes are written to the stream, blocking or retrying when necessary.

Parameters
[in]addrAddress of the data to write.
[in]sizeSize in bytes of the data to write.
[out]written_sizeActually written size in bytes. Can be less than size in case of error in the middle of the write.
[in,out]reportWhere to report errors.
Returns
True on success, false on error.

Implements ts::AbstractWriteStreamInterface.

◆ writeStreamBuffer()

virtual bool ts::ForkPipe::writeStreamBuffer ( const void *  addr,
size_t  size 
)
overrideprotectedvirtual

Write buffered data to underlying output devicen whatever it is.

Must be implemented by subclasses.

Parameters
[in]addrBuffered data address.
[in]sizeBuffered data size in bytes.
Returns
True on success, false on error.

Implements ts::AbstractOutputStream.

◆ readStreamComplete()

virtual bool ts::AbstractReadStreamInterface::readStreamComplete ( void *  addr,
size_t  max_size,
size_t &  ret_size,
Report report 
)
virtualinherited

Read complete data from the stream.

Wait and read exactly max_size bytes. If ret_size is less than max_bytes, it is not possible to read more. End of file has probably been reached.

Parameters
[out]addrAddress of the buffer for the incoming data.
[in]max_sizeMaximum size in bytes of the buffer.
[out]ret_sizeReturned input size in bytes.
[in,out]reportWhere to report errors.
Returns
True on success, false on error.

◆ readStreamChunks()

virtual bool ts::AbstractReadStreamInterface::readStreamChunks ( void *  addr,
size_t  max_size,
size_t  chunk_size,
size_t &  ret_size,
Report report 
)
virtualinherited

Read chunks of data from the stream.

Parameters
[out]addrAddress of the buffer for the incoming data.
[in]max_sizeMaximum size in bytes of the buffer.
[in]chunk_sizeIf not zero, make sure that the input size is always a multiple of chunk_size. If the initial read ends in the middle of a chunk, read again and again, up to the end of the current chunk or end of file.
[out]ret_sizeReturned input size in bytes.
[in,out]reportWhere to report errors.
Returns
True on success, false on error.

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