iofunc_lseek_default()
QNX SDP8.0C Library ReferenceAPIDeveloper
Default handler for _IO_LSEEK messages
Synopsis:
#include <sys/iofunc.h>
int iofunc_lseek_default( resmgr_context_t* ctp,
io_lseek_t* msg,
iofunc_ocb_t* ocb );
Arguments:
- ctp
- A pointer to a resmgr_context_t structure that the resource-manager library uses to pass context information between functions.
- msg
- A pointer to the io_lseek_t structure that contains the message that the resource manager received. For more information, see the documentation for iofunc_lseek().
- ocb
- A pointer to the iofunc_ocb_t structure for the Open Control Block that was created when the client opened the resource.
Library:
libc
Use the -l c option to qcc to link against this library. This library is usually included automatically.
Description:
The iofunc_lseek_default() function implements POSIX semantics for the client's lseek() call, which is received as an _IO_LSEEK message by the resource manager.
You can place this function directly into the resmgr_io_funcs_t table passed as the io_funcs argument to resmgr_attach(), at the lseek position, or you can call iofunc_func_init() to initialize all of the functions to their default values.
The iofunc_lseek_default() function calls iofunc_lseek() to do the actual work.
Returns:
- -1
- Success; the resource manager library should return a one-part IOV to the client.
- EOK
- The message is a combine message, and no error occurred.
- EINVAL
- The whence member in the _IO_LSEEK message wasn't one of SEEK_SET, SEEK_CUR, or SEEK_END, or the resulting position after the offset was applied resulted in a negative number (overflow).
- EOVERFLOW
- The resulting file offset is a value that can't be represented correctly in an object of type off_t.
Classification:
Safety: | |
---|---|
Cancellation point | No |
Signal handler | Yes |
Thread | Yes |
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