SWI-Prolog -- API-function PL_get

Documentation
- Reference manual
  - Foreign Language Interface
    - Foreign access to Prolog IO streams
      - Get IO stream handles
        
        PL_get_stream()
        
        PL_get_stream_from_blob()
        
        PL_acquire_stream()
        
        PL_release_stream()
- Packages

Availability:C-language interface function

int PL_get_stream(term_t t, IOSTREAM **s, int flags)

Get a stream handle from the Prolog term t. Returns TRUE on success and FALSE on failure, by default generating an exception. The flags argument is a bitwise disjunction of these flags:

SIO_INPUT: Get an input stream. If t is a stream pair (see stream_pair/3), return the input channel. If t is an output stream the function fails.
SIO_OUTPUT: Get an output stream. See SIO_INPUT for details. If neither SIO_OUTPUT nor SIO_INPUT is given t may not be a pair.
SIO_TRYLOCK: Return FALSE if the stream cannot be locked immediately. No error is generated.
SIO_NOERROR: If the function fails no exception is produced.

The returned stream is owned by the calling thread using PL_acquire_stream().