Manipulate file descriptor flags.

diff --git a/fdflags.c b/fdflags.c
new file mode 100644 (file)
index 0000000..85ef67c
--- /dev/null
+++ b/fdflags.c
@@ -0,0 +1,75 @@
+/* -*-c-*-
+ *
+ * $Id: fdflags.c,v 1.1 1999/07/26 23:16:59 mdw Exp $
+ *
+ * Manipulates flags on file descriptors
+ *
+ * (c) 1999 Straylight/Edgeware
+ */
+
+/*----- Licensing notice --------------------------------------------------* 
+ *
+ * This file is part of the mLib utilities library.
+ *
+ * mLib is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Library General Public License as
+ * published by the Free Software Foundation; either version 2 of the
+ * License, or (at your option) any later version.
+ * 
+ * mLib is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Library General Public License for more details.
+ * 
+ * You should have received a copy of the GNU Library General Public
+ * License along with mLib; if not, write to the Free
+ * Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
+ * MA 02111-1307, USA.
+ */
+
+/*----- Revision history --------------------------------------------------* 
+ *
+ * $Log: fdflags.c,v $
+ * Revision 1.1  1999/07/26 23:16:59  mdw
+ * Manipulate file descriptor flags.
+ *
+ */
+
+/*----- Header files ------------------------------------------------------*/
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include <fcntl.h>
+
+#include "fdflags.h"
+
+/*----- Main code ---------------------------------------------------------*/
+
+/* --- @fdflags@ --- *
+ *
+ * Arguments:  @int fd@ = file descriptor to fiddle with
+ *             @unsigned fbic, fxor@ = file flags to set and clear
+ *             @unsigned fdbic, fdxor@ = descriptor flags to set and clear
+ *
+ * Returns:    Zero if successful, @-1@ if not.
+ *
+ * Use:                Sets file descriptor flags in what is, I hope, an obvious
+ *             way.
+ */
+
+int fdflags(int fd, unsigned fbic, unsigned fxor,
+           unsigned fdbic, unsigned fdxor)
+{
+  int f;
+
+  if ((f = fcntl(fd, F_GETFL)) == -1 ||
+      fcntl(fd, F_SETFL, (f & ~fbic) ^ fxor) == -1 ||
+      (f = fcntl(fd, F_GETFD)) == -1 ||
+      fcntl(fd, F_SETFD, (f & ~fdbic) ^ fdxor) == -1)
+    return (-1);
+  return (0);
+}
+
+/*----- That's all, folks -------------------------------------------------*/

diff --git a/fdflags.h b/fdflags.h
new file mode 100644 (file)
index 0000000..411fb2d
--- /dev/null
+++ b/fdflags.h
@@ -0,0 +1,77 @@
+/* -*-c-*-
+ *
+ * $Id: fdflags.h,v 1.1 1999/07/26 23:16:59 mdw Exp $
+ *
+ * Manipulates flags on file descriptors
+ *
+ * (c) 1999 Straylight/Edgeware
+ */
+
+/*----- Licensing notice --------------------------------------------------* 
+ *
+ * This file is part of the mLib utilities library.
+ *
+ * mLib is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Library General Public License as
+ * published by the Free Software Foundation; either version 2 of the
+ * License, or (at your option) any later version.
+ * 
+ * mLib is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Library General Public License for more details.
+ * 
+ * You should have received a copy of the GNU Library General Public
+ * License along with mLib; if not, write to the Free
+ * Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
+ * MA 02111-1307, USA.
+ */
+
+/*----- Revision history --------------------------------------------------* 
+ *
+ * $Log: fdflags.h,v $
+ * Revision 1.1  1999/07/26 23:16:59  mdw
+ * Manipulate file descriptor flags.
+ *
+ */
+
+#ifndef FDFLAGS_H
+#define FDFLAGS_H
+
+#ifdef __cplusplus
+  extern "C" {
+#endif
+
+/*----- Header files ------------------------------------------------------*/
+
+#include <fcntl.h>
+
+/*----- Magic numbers -----------------------------------------------------*/
+
+#ifndef FD_CLOEXEC
+#  define FD_CLOEXEC 1
+#endif
+
+/*----- Functions provided ------------------------------------------------*/
+
+/* --- @fdflags@ --- *
+ *
+ * Arguments:  @int fd@ = file descriptor to fiddle with
+ *             @unsigned fbic, fxor@ = file flags to set and clear
+ *             @unsigned fdbic, fdxor@ = descriptor flags to set and clear
+ *
+ * Returns:    Zero if successful.
+ *
+ * Use:                Sets file descriptor flags.
+ */
+
+int fdflags(int /*fd*/, unsigned /*fbic*/, unsigned /*fxor*/,
+           unsigned /*fdbic*/, unsigned /*fdxor*/);
+
+/*----- That's all, folks -------------------------------------------------*/
+
+#ifdef __cplusplus
+  }
+#endif
+
+#endif

diff --git a/man/fdflags.3 b/man/fdflags.3
new file mode 100644 (file)
index 0000000..77f9147
--- /dev/null
+++ b/man/fdflags.3
@@ -0,0 +1,82 @@
+.\" -*-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>