.\" -*-nroff-*-
.de VS
.sp 1
.RS
.nf
.ft B
..
.de VE
.ft R
.fi
.RE
.sp 1
..
.TH fdflags 3 "23 July 1999" "Straylight/Edgeware" "mLib utilities library"
.SH "NAME"
fdflags \- set file and file descriptor flags
.\" @fdflags
.SH "SYNOPSIS"
.nf
.B "#include <mLib/fdflags.h>"

.BI "int fdflags(int " fd ,
.BI "            unsigned " fbic ", unsigned " fxor ,
.BI "            unsigned " fdbic ", unsigned " fdxor );
.fi
.SH "DESCRIPTION"
.B fdflags
is a convenience function for setting file and file descriptor flags
using
.BR fcntl (2).
.PP
The file flags are read using
.BR F_GETFL ,
the new flags are calculated as
.sp 1
.RS
.I new-flags
=
.BI ( old-flags
.B &
.BI ~ fbic )
.B ^
.I fxor
.RE
.sp 1
and the result written back using
.BR F_SETFL .
.PP
Similarly the file descriptor flags are read using
.BR F_GETFD ,
the new flags calculated as
.sp 1
.RS
.I new-flags
=
.BI ( old-flags
.B &
.BI ~ fdbic )
.B ^
.I fdxor
.RE
.sp 1
and the result written back using
.BR F_SETFD .
.PP
If all went well,
.B fdflags
returns zero; if there was an error, \-1 is returned.
.SH "EXAMPLES"
To set the non-blocking and close-on-exec flags:
.VS
fdflags(fd, O_NONBLOCK, O_NONBLOCK, FD_CLOEXEC, FD_CLOEXEC);
.VE
To clear the non-blocking and close-on-exec flags:
.VS
fdflags(fd, O_NONBLOCK, 0, FD_CLOEXEC, 0);
.VE
.sp -1
.SH "SEE ALSO"
.BR mLib (3).
.SH "AUTHOR"
Mark Wooding, <mdw@distorted.org.uk>