.\" 
.\" Copyright (c) 1994 Joerg Wunsch
.\" 
.\" All rights reserved.
.\" 
.\" This program is free software.
.\" 
.\" Redistribution and use in source and binary forms, with or without
.\" modification, are permitted provided that the following conditions
.\" are met:
.\" 1. Redistributions of source code must retain the above copyright
.\"    notice, this list of conditions and the following disclaimer.
.\" 2. Redistributions in binary form must reproduce the above copyright
.\"    notice, this list of conditions and the following disclaimer in the
.\"    documentation and/or other materials provided with the distribution.
.\" 3. All advertising materials mentioning features or use of this software
.\"    must display the following acknowledgement:
.\" This product includes software developed by Joerg Wunsch
.\" 4. The name of the developer may not be used to endorse or promote
.\"    products derived from this software without specific prior written
.\"    permission.
.\" 
.\" THIS SOFTWARE IS PROVIDED BY THE DEVELOPERS ``AS IS'' AND ANY EXPRESS OR
.\" IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
.\" OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
.\" IN NO EVENT SHALL THE DEVELOPERS BE LIABLE FOR ANY DIRECT, INDIRECT,
.\" INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
.\" NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
.\" DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
.\" THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
.\" (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
.\" THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
.\" 
.\" 
.\" libcompat man page,
.\" written June 15, 1993 by Joerg Wunsch
.\"
.Dd June 15, 1993
.Os
.Dt LIBCOMPAT 3
.Sh NAME
.Nm libcompat
.Nd compatibility library for older programs
.Sh SYNOPSIS
.Fd #include <sgtty.h>
.Fn "int stty" "int fd" "struct sgttyb *s" ;
.Fn "int gtty" "int fd" "struct sgttyb *s" ;
.Fd #include <sys/timeb.h>
.Fn "int ftime" "struct timeb *tp" ;
.Fd #include <time.h>
.Fn "int cftime" "char *s" "char *format" "const time_t *clock" ;
.Fn "int ascftime" "char *s" "const char *format" "const struct tm *tmptr" ;

.Fn "char *re_comp" "char *s" ;
.Fn "int re_exec" "char *s" ;
.Fd #include <sys/types.h>
.Fn "int setruid" "uid_t uid" ;
.Fn "int setrgid" "gid_t gid" ;
.Sh DESCRIPTION
.Em The functions described here are obsoleted .
.Em The sole purpose \&of this library \&is providing
.Em a compatibility module for older programs .
To use the library, an option of
.Fl lcompat
has to be specified when linking those programs.

The functions
.Nm stty
and
.Nm gtty
set or get, respectively, the terminal control flags from/into a
variable of type
.Em struct sgttyb .
They are obsoleted by the new terminal controlling interface, see
.Xr termios 3 .
There used to be macros instead of functions, too.

The function
.Nm ftime
returns information on the current time as well as the timezone.
It is obsoleted by
.Xr gettimeofday 3 .
Note further that the timezone information is no longer kept inside
the kernel, hence neither
.Xr gettimeofday 3 ,
nor
.Nm ftime
will return useful values for their timezone-related arguments. See
.Xr tzset 3
and
.Xr ctime 3
for an up-to-date timezone handling.

Use of the functions
.Nm cftime
and
.Nm ascftime
is strongly deprecated, since there is no way to check for a buffer
overflow condition. Use
.Xr strftime 3
instead.

.Nm Ascftime
is almost identical with
.Xr strftime 3 ,
with the only exception there's no parameter to tell about the
maximal buffer length, and the
.Ar format
parameter defaults to
.Dq %C
if a
.Em NULL
pointer is given.

.Nm Cftime
does the same job, but it first invokes
.Xr localtime 3
in order to convert the given
.Ar clock ,
then also performs the conversions as requested by the
.Ar format
argument.

.Nm Setruid
and
.Nm setrgid
have been used previously to set the real user-ID or real group-ID,
respectively. They are no longer available, because they are
incompatible with the POSIX security model. If a process wants to set
its real user-ID, then it must also simultaneously set its effective and
saved IDs, which is what
.Nm setuid
does. Similiar considerations apply to
.Nm setrgid .

The functions
.Nm re_comp
and
.Nm re_exec
provide a traditional interface to the regular expression matching
routines
.Xr regcomp 3
and
.Xr regexec 3 .

.Nm Re_comp
compiles a string into an internal form suitable for pattern
matching.
.Nm Re_exec
checks the argument string against the last string
passed to
.Nm re_comp .

.Nm Re_comp
returns 0 if the string s was compiled successfully;
otherwise a string containing an error message is returned. If
.Nm re_comp
is passed 0 or a null string, it returns without changing the
currently compiled regular expression.

.Nm Re_exec
returns 1 if the string s matches the last compiled regular
expression, 0 if the string s failed to match the last compiled
regular expression, and -1 if the compiled regular expression was
invalid
.Pq indicating an internal error .

Note that
.Nm re_comp
and
.Nm re_exec
need the
.Xr regexp 3
library with the traditional
.Pq V8
function call interface rather than the new library as
contained in the standard C library. The
.Xr regexp 3
library is also part of libcompat.a.

.Sh RETURN VALUES
The functions usually return with a negative value on error.

The
.Nm cftime
and
.Nm ascftime
function return the number of characters written to the output
buffer
.Ar s ,
not counting the trailing null character.

.Sh SEE ALSO
.Xr termios 3 ;
.Xr gettimeofday 3 ;
.Xr strftime 3 ,
.Xr tzset 3 ,
.Xr ctime 3 ,
.Xr localtime 3 ;
.Xr setreuid 2 ,
.Xr setuid 3 ,
.Xr setregid 2 ,
.Xr setgid 3 ;
.Xr regcomp 3 ,
.Xr regexec 3 .