rdchk()
Check to see if a read is likely to succeed
Synopsis:
#include <unix.h>
int rdchk( int fd );
Arguments:
- fd
- The file descriptor that you want to check.
Library:
libc
Use the -l c option to qcc to link against this library. This library is usually included automatically.
This function is in libc.a, but not in libc.so
(in order to save space).
Description:
The rdchk() function checks to see if a read from the file descriptor, fd, is likely to succeed.
Returns:
The number of characters waiting to be read, or -1 if an error occurred (errno is set).
Errors:
- ENOTTY
- The fd argument isn't the file descriptor for a character device.
Classification:
Safety: | |
---|---|
Cancellation point | No |
Interrupt handler | No |
Signal handler | Yes |
Thread | Yes |