rdchk(S)
rdchk --
checks to see if there is data to be read
Syntax
cc ... -lx
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 the process will not block when a read is attempted
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);
Diagnostics
rdchk
returns -1 if an error occurs (for example, EBADF), 0 when the process
will block if it issues a
read and 1 if it is okay to read.
EBADF is returned if a rdchk
is used on a semaphore file or if
the file specified does not exist.
See also
read(S)
Standards conformance
rdchk is not part of any currently supported standard;
it is an extension of AT&T System V provided by the Santa Cruz Operation.
© 2003 Caldera International, Inc. All rights reserved.
SCO OpenServer Release 5.0.7 -- 11 February 2003