RDCHK(S) XENIX System V RDCHK(S)
Name
rdchk - Checks to see if there is data to be read.
Syntax
int rdchk(fdes);
int fdes;
Description
rdchk checks to see if a process will block if it attempts
to read the file designated by fdes. rdchk returns 1 if
there is data to be read or if it is the end of the file
(EOF). In this context, the proper sequence of calls using
rdchk is:
if(rdchk(fildes) > 0)
read(fildes, buffer, nbytes);
See Also
read(S)
Diagnostics
rdchk returns -1 if an error occurs (e.g., EBADF), 0 if the
process will block if it issues a read and 1 if it is okay
to read. EBADF is returned if a rdchk is done on a
semaphore file or if the file specified doesn't exist.
Notes
This function must be linked with the linker option -lx.
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