Raised by the Put or Get operations (and also by Write and Read) if the underlying system operations indicate any reading or writing error.

Stream operations on an In_Stream will raise End_Error if EOF is encountered.

Stream operations on the returned stream may raise Mode_Error if writing on an In_Stream or reading from an Out_Stream is attempted.

Raised by Open if the command cannot be executed.

Raised by any stream operation if the stream is not open (and by Open, if it already is open).

Used in Open to specify the type of the stream.

I have found no indication whatsoever about the type of the underlying C stream (binary or text mode?). Although you can write and read binary data to and from a Pipe_Stream, it's probably prudent to consider these streams as text-only, because they set up pipes to or from an external processes stdin or stdout handles, which are defined by the ISO C standard as text streams.

Executes Command, which may contain arguments, setting it up such that the executed command's stdin comes from the returned stream if Mode is Out_Stream, or the command's stdout can be read from that stream if Mode is In_Stream. Note that "in" and "out" are from the caller's perspective.

If Close = True, the stream is closed automatically when the stream object disappears. Note that this may involve waiting until the external command terminates. Out_Streams always are closed automatically.

Raises Name_Error if the Command cannot be executed, or Use_Error if the stream is already open.

Note that an output filter is created using a stream of mode Out_Stream. The external process will share its stdout with the calling application, so you should carefully flush your stdout before opening such a pipe, otherwise, output may become garbled and mixed up. The same applies to an input filter: it shares its stdin with the calling application! Unfortunately, one cannot flush an input stream (that would be a meaningless operation anyway), so be careful!

One way to avoid such problems is using the Std_In parameter. If it is not the empty string, the command's stdin is redirected to come from the given filename (which had better be valid). In other words, the command actually executed is Command & " <" & Std_In. If this feature is used, the caller is responsible for removing the file, if that is desired.

Closes a stream obtained through Open. Raises Use_Error if the stream has not been opened.

An Out_Stream must be closed, otherwise your program might not terminate. therefore, Pipe_Streams are controlled, and any Out_Stream is closed automatically when the stream object disappears.

An In_Stream is only closed automatically if it has been opened with Close = True, because closing such a stream may involve waiting until the external command has terminated.

Note: this is a blocking call: it waits until the executed command has terminated, and then returns that commands exit code.

Returns True if the Stream is open, and False otherwise.

Raises Mode_Error if the Stream is an Out_Stream. Otherwise, returns True if the In_Streams end has been reached and False otherwise.

Same semantics as Ada.Text_IO.Put.

Same semantics as Put for a string.

Same semantics as Ada.Text_IO.Put_Line.

Same semantics as Ada.Text_IO.Get.

Same semantics as Ada.Text_IO.Get.

Same semantics as Ada.Text_IO.Get_Line.

As Ada.Text_IO.Get_Line, but always returns a full line.