xref: /freebsd/contrib/nvi/ex/ex_equal.c (revision 2be1a816b9ff69588e55be0a84cbe2a31efc0f2f)
1 /*-
2  * Copyright (c) 1992, 1993, 1994
3  *	The Regents of the University of California.  All rights reserved.
4  * Copyright (c) 1992, 1993, 1994, 1995, 1996
5  *	Keith Bostic.  All rights reserved.
6  *
7  * See the LICENSE file for redistribution information.
8  */
9 
10 #include "config.h"
11 
12 #ifndef lint
13 static const char sccsid[] = "@(#)ex_equal.c	10.10 (Berkeley) 3/6/96";
14 #endif /* not lint */
15 
16 #include <sys/types.h>
17 #include <sys/queue.h>
18 
19 #include <bitstring.h>
20 #include <limits.h>
21 #include <stdio.h>
22 
23 #include "../common/common.h"
24 
25 /*
26  * ex_equal -- :address =
27  *
28  * PUBLIC: int ex_equal __P((SCR *, EXCMD *));
29  */
30 int
31 ex_equal(sp, cmdp)
32 	SCR *sp;
33 	EXCMD *cmdp;
34 {
35 	recno_t lno;
36 
37 	NEEDFILE(sp, cmdp);
38 
39 	/*
40 	 * Print out the line number matching the specified address,
41 	 * or the number of the last line in the file if no address
42 	 * specified.
43 	 *
44 	 * !!!
45 	 * Historically, ":0=" displayed 0, and ":=" or ":1=" in an
46 	 * empty file displayed 1.  Until somebody complains loudly,
47 	 * we're going to do it right.  The tables in excmd.c permit
48 	 * lno to get away with any address from 0 to the end of the
49 	 * file, which, in an empty file, is 0.
50 	 */
51 	if (F_ISSET(cmdp, E_ADDR_DEF)) {
52 		if (db_last(sp, &lno))
53 			return (1);
54 	} else
55 		lno = cmdp->addr1.lno;
56 
57 	(void)ex_printf(sp, "%ld\n", lno);
58 	return (0);
59 }
60