BloombergLP::bsls::OutputRedirector

This class provides a facility for redirecting stdout and stderr to temporary files, retrieving output from the respective temporary file and comparing the output to user-supplied character buffers. An OutputRedirector object can be in an un-redirected state or a redirected state. If the redirector is in a redirected state, it will redirect either stdout or stderr, but not both simultaneously. An OutputRedirector object has the concept of a scratch buffer, where output captured from the process' stdout or stderr stream is stored when the OutputRedirector object is in the redirected state. Throughout this class, the term "captured output" refers to data that has been written to the stdout or stderr stream and is waiting to be loaded into the scratch buffer. Each time the load method is called, the scratch buffer is truncated, and the captured output is moved into the scratch buffer. When this is done, there is no longer any captured output.

Synopsis

Declared in <bsls_outputredirector.h>

class OutputRedirector;

Enums

Name	Description
`Stream`	Identifies the standard stream redirected by this object.

Member Functions

Name	Description
`OutputRedirector` [constructor]	Create an `OutputRedirector` in an un-redirected state, and with an empty scratch buffer. Upon a call to `enable`, this redirector will be responsible for redirecting the stream associated with the specified `which` to a temporary file. The behavior is undefined unless `which` is equal to `OutputRedirector::e_STDOUT_STREAM` or `OutputRedirector::e_STDERR_STREAM`.
`~OutputRedirector` [destructor]	Destroy this `OutputRedirector` object. If the object is in a redirected state, the original stream will be restored to its initial target and the temporary file to which the stream was redirected will be deleted.
`clear`	Reset the scratch buffer to empty. The behavior is undefined unless `enable` has been previously called successfully (after the latest call to `disable` if `disable` has been called successfully).
`compare`	`compare` overloads
`disable`	If the redirector is in a redirected state, restore the original target of the redirected stream and close the temporary buffer. If the redirector is not in a redirected state, this method is a no-op. Calling this method invalidates all output in the temporary file, so a call to `load` after the next successful `enable` call will not load any output that was previously written to the file. This method does not clear the scratch buffer, so one may call `load` before calling `disable`, and the contents will be available after `disable` is called. If `disable` fails to disable the redirection, it will end the program by calling `std::abort`.
`enable`	If the `Stream` specified at construction was `e_STDOUT_STREAM`, redirect `stdout` to a temporary file. If the `Stream` specified at construction was `e_STDERR_STREAM`, redirect `stderr` to a temporary file. The temporary file to which the stream is redirected will be created the first time `enable` is called, and will be deleted when this object is destroyed. If `enable` fails to redirect either `stdout` or `stderr` it will end the program by calling `std::abort`.
`getOutput`	Return the address of the scratch buffer.
`isOutputReady`	Return `true` if the captured output has been loaded into the scratch buffer, and `false` otherwise.
`isRedirecting`	Return `true` if `stdout` or `stderr` has been successfully redirected, and `false` otherwise.
`load`	Read captured output into the scratch buffer. Return `true` if all captured output was successfully loaded, and `false` otherwise. Note that captured output is allowed to have zero length. The behavior is undefined unless `enable` has been previously called successfully (after the latest call to `disable`, if `disable` has been called successfully).
`nonRedirectedStream`	Return the value of the global `stdout` or `stderr` corresponding to the stream that is not intended to be redirected by this object.
`outputSize`	Return the number of bytes currently loaded into the scratch buffer.
`redirectedStream`	Return the value of the global `stdout` or `stderr` corresponding to the stream that is intended to be redirected by this object.
`redirectedStreamId`	Return `OutputRedirector::e_STDOUT_STREAM` if this object is responsible for redirecting `stdout`, and `OutputRedirector::e_STDERR_STREAM` if this object is responsible for redirecting `stderr`.

Static Data Members

Name	Description
`k_OUTPUT_REDIRECTOR_BUFFER_SIZE`	The size of the buffer used to store the captured values loaded in the `stdout` and `stderr` error streams.
`k_PATH_BUFFER_SIZE`	The size of the buffer used to hold a file name.