Enum subprocess::Redirection
[−]
[src]
pub enum Redirection { None, File(File), Pipe, Merge, }
Instruction what to do with a stream in the child process.
Redirection
values are used for the stdin
, stdout
, and
stderr
field of the PopenConfig
struct. They tell
Popen::create
how to set up the standard streams in the child
process and the corresponding fields of the Popen
struct in the
parent.
Variants
None
Do nothing with the stream.
The stream is typically inherited from the parent. The field
in Popen
corresponding to the stream will be None
.
File(File)
Redirect the stream to the specified open File
.
This does not create a pipe, it simply spawns the child so that the specified stream sees that file. The child can read from or write to the provided file on its own, without any intervention by the parent.
The field in Popen
corresponding to the stream will be
None
.
Pipe
Redirect the stream to a pipe.
This creates a unidirectional pipe for the standard stream.
One end is passed to the child process and configured as one
of its standard streams, and the other end is available to the
parent as a File
in the corresponding field of the Popen
struct.
The field in Popen
corresponding to the stream will be
None
.
Merge
Merge the stream to the other output stream.
This is only valid for output streams. Using
Redirection::Merge
for PopenConfig::stderr
requests the
child's stderr to be the same underlying file as the child's
output stream (whatever that is), equivalent to the 2>&1
operator of the Bourne shell. Analogously, using
Redirection::Merge
for PopenConfig::stdout
is equivalent
to 1>&2
in the shell.
Specifying Redirection::Merge
for PopenConfig::stdin
or
specifying it for both stdout
and stderr
is invalid and
will cause Popen::create
to return
Err(PopenError::LogicError)
.
Methods
impl Redirection
[src]
fn try_clone(&self) -> IoResult<Redirection>
Clone the underlying Redirection
, or return an error.
Can fail in File
variant.