freebsd-dev/lib/libcompat/4.3/re_comp.3
Ed Schouten 763ed73371 Trim down libcompat by removing <regexp.h>.
Erwin ran an exp-run with libcompat and <regexp.h> removed. It turns out
the regexp library is almost entirely unused. In fact, it looks like it
is sometimes used by accident. Because these function names clash with
libc's <regex.h>, some application use both <regex.h> and libcompat,
which means they link against the wrong regex library.

This commit removes the regexp library and reimplements re_comp() and
re_exec() using <regex.h>. It seems the grammar of the regular
expressions accepted by these functions is similar to POSIX EREs.

After this commit, 1 low-profile port will be broken, but the maintainer
already has a patch for it sitting in his mailbox.
2010-03-14 10:18:58 +00:00

121 lines
3.3 KiB
Groff

.\" Copyright (c) 1980, 1991, 1993
.\" The Regents of the University of California. All rights reserved.
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.\" notice, this list of conditions and the following disclaimer in the
.\" documentation and/or other materials provided with the distribution.
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.\" may be used to endorse or promote products derived from this software
.\" without specific prior written permission.
.\"
.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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.\" 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
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.\" SUCH DAMAGE.
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.\" @(#)re_comp.3 8.1 (Berkeley) 6/4/93
.\" $FreeBSD$
.\"
.Dd June 4, 1993
.Dt RE_COMP 3
.Os
.Sh NAME
.Nm re_comp ,
.Nm re_exec
.Nd regular expression handler
.Sh LIBRARY
.Lb libcompat
.Sh SYNOPSIS
.In unistd.h
.Ft char *
.Fn re_comp "const char *s"
.Ft int
.Fn re_exec "const char *s"
.Sh DESCRIPTION
.Bf -symbolic
This interface is made obsolete by
.Xr regex 3 .
.Ef
.Pp
The
.Fn re_comp
function
compiles a string into an internal form suitable for pattern matching.
The
.Fn re_exec
function
checks the argument string against the last string passed to
.Fn re_comp .
.Pp
The
.Fn re_comp
function
returns 0 if the string
.Fa s
was compiled successfully; otherwise a string containing an
error message is returned.
If
.Fn re_comp
is passed 0 or a null string, it returns without changing the currently
compiled regular expression.
.Pp
The
.Fn re_exec
function
returns 1 if the string
.Fa s
matches the last compiled regular expression, 0 if the string
.Fa s
failed to match the last compiled regular expression, and \-1 if the compiled
regular expression was invalid (indicating an internal error).
.Pp
The strings passed to both
.Fn re_comp
and
.Fn re_exec
may have trailing or embedded newline characters;
they are terminated by
.Dv NUL Ns s .
The regular expressions recognized are described in the manual entry for
.Xr ed 1 ,
given the above difference.
.Sh DIAGNOSTICS
The
.Fn re_exec
function
returns \-1 for an internal error.
.Pp
The
.Fn re_comp
function
returns
.Dq no previous regular expression
or one of the strings generated by
.Xr regerror 3 .
.Sh SEE ALSO
.Xr ed 1 ,
.Xr egrep 1 ,
.Xr ex 1 ,
.Xr fgrep 1 ,
.Xr grep 1 ,
.Xr regex 3
.Sh HISTORY
The
.Fn re_comp
and
.Fn re_exec
functions appeared in
.Bx 4.0 .