Manipulate file descriptor flags.

[mLib] / man / fdflags.3

diff --git a/man/fdflags.3 b/man/fdflags.3
new file mode 100644 (file)
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+.\" -*-nroff-*-
+.de VS
+.sp 1
+.RS
+.nf
+.ft B
+..
+.de VE
+.ft R
+.fi
+.RE
+.sp 1
+..
+.TH fdflags 3 "23 July 1999" mLib
+.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@nsict.org>