12.3.20 SP_fopen()

Synopsis

     #include <sicstus/sicstus.h>
     
     spio_t_error_code
     SP_fopen(
       char const *pathname,
       void *reserved,
       spio_t_bits options,
       SP_stream **pstream);

Opens a file and creates a SICStus stream reading and/or writing to it.

Arguments

pathname
The path to the file as an encoded string. It is expanded by SP_expand_file_name() unless the option SP_FOPEN_OPTION_NOEXPAND is specified, in which case the path must already have been expanded by SP_expand_file_name().
reserved
Reserved, should be NULL.
read_options
The following bits can be set:
SP_FOPEN_OPTION_READ
Open the file for reading. The file must exist.
SP_FOPEN_OPTION_WRITE
Open the file for writing. The file is overwritten if it exists. The file is created if it does not exist.
SP_FOPEN_OPTION_APPEND
Open the file for writing but start writing at the end of the file if it exists. The file is created if it does not exist.
SP_FOPEN_OPTION_BINARY
Open the file as a binary (byte) stream.
SP_FOPEN_OPTION_TEXT
Open the file as a text stream. The default character encoding is Latin 1 (i.e. the 8 bit subset of UNICODE). The default end of line convention is OS specific.
SP_FOPEN_OPTION_AUTOFLUSH
After writing to this stream, Prolog predicates will do a flush_output/1. In essence this ensures that the stream behaves as if it were unbuffered.
SP_FOPEN_OPTION_INTERACTIVE
Treat this stream as an interactive stream. Implies SP_CREATE_STREAM_OPTION_AUTOFLUSH.
SP_FOPEN_OPTION_NOEXPAND
The pathname has already been expanded with SP_expand_file_name() or something similar. This implies that pathname is an absolute path. If this option is not specified, pathname is expanded with SP_expand_file_name() before use.

pstream
On successful return, *pstream will be set to the created stream.

Return Value

On success, *pstream will be set to the created stream and SPIO_S_NOERR or some other success code returned.

On failure, some SPIO failure code will be returned. Error codes with special meaning for SP_fopen():

SPIO_E_FILE_NOT_FOUND
The file does not exist.
SPIO_E_FILE_ACCESS
Insufficient permissions to open or create the file.
SPIO_E_OPEN_ERROR
Generic error during open.

Other error codes may also be returned.

See Also

Prolog Streams.


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