io_open()
QNX SDP8.0Image Library ReferenceAPIDeveloperProgramming
Initialize an IO stream
Synopsis:
#include <io/io.h>
io_stream_t *io_open( io_open_f *open_f,
io_mode_t mode, ...)
Arguments:
- open_f
- A pointer to a function to establish a stream. There are two functions supplied by the library: IO_FD() (for fd-based reading/writing) and IO_MEM() (for memory buffer based reading/writing). See below.
- mode
- The open mode, either IO_READ or IO_WRITE.
- ...
- Additional parameters depending on the open_f specified, described below.
Library:
libimg
Use the -l img option to qcc to link against this library.
Description:
This function initializes a stream. The stream can be a fd-based, or a memory buffer, depending on the open_f specified:
- IO_FD()
- Buffered streaming for unix-type fd's. An additional parmameter is required: an int specifying the (previously opened) fd that is ready for reading or writing.
- IO_MEM()
- Streaming support for a memory buffer. Additional parameters are required (in order):
- an unsigned to specify size of the memory buffer. This must be non-zero.
- a void pointer to specify the address of the buffer.
When your application is finished with a stream, it should call io_close() to release it.
Returns:
A pointer to the stream object, or NULL if an error occurred (errno is set).
Errors:
- ENOMEM
- Insufficient memory to allocate structures.
- EINVAL
- Invalid open_f or mode.
- ENOTSUP
- Mode not supported for stream.
Classification:
Image library
| Safety: | |
|---|---|
| Signal handler | No |
| Thread | No |
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