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.

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