xref: /openbsd/usr.bin/vi/ex/ex_join.c (revision 3cab2bb3)
1 /*	$OpenBSD: ex_join.c,v 1.8 2016/01/06 22:28:52 millert Exp $	*/
2 
3 /*-
4  * Copyright (c) 1992, 1993, 1994
5  *	The Regents of the University of California.  All rights reserved.
6  * Copyright (c) 1992, 1993, 1994, 1995, 1996
7  *	Keith Bostic.  All rights reserved.
8  *
9  * See the LICENSE file for redistribution information.
10  */
11 
12 #include "config.h"
13 
14 #include <sys/types.h>
15 #include <sys/queue.h>
16 
17 #include <bitstring.h>
18 #include <ctype.h>
19 #include <limits.h>
20 #include <stdio.h>
21 #include <stdlib.h>
22 #include <string.h>
23 
24 #include "../common/common.h"
25 
26 /*
27  * ex_join -- :[line [,line]] j[oin][!] [count] [flags]
28  *	Join lines.
29  *
30  * PUBLIC: int ex_join(SCR *, EXCMD *);
31  */
32 int
33 ex_join(SCR *sp, EXCMD *cmdp)
34 {
35 	recno_t from, to;
36 	size_t blen, clen, len, tlen;
37 	int echar, extra, first;
38 	char *bp, *p, *tbp;
39 
40 	NEEDFILE(sp, cmdp);
41 
42 	from = cmdp->addr1.lno;
43 	to = cmdp->addr2.lno;
44 
45 	/* Check for no lines to join. */
46 	if (!db_exist(sp, from + 1)) {
47 		msgq(sp, M_ERR, "No following lines to join");
48 		return (1);
49 	}
50 
51 	GET_SPACE_RET(sp, bp, blen, 256);
52 
53 	/*
54 	 * The count for the join command was off-by-one,
55 	 * historically, to other counts for other commands.
56 	 */
57 	if (FL_ISSET(cmdp->iflags, E_C_COUNT))
58 		++cmdp->addr2.lno;
59 
60 	/*
61 	 * If only a single address specified, or, the same address
62 	 * specified twice, the from/two addresses will be the same.
63 	 */
64 	if (cmdp->addr1.lno == cmdp->addr2.lno)
65 		++cmdp->addr2.lno;
66 
67 	clen = tlen = 0;
68         for (first = 1,
69 	    from = cmdp->addr1.lno, to = cmdp->addr2.lno; from <= to; ++from) {
70 		/*
71 		 * Get next line.  Historic versions of vi allowed "10J" while
72 		 * less than 10 lines from the end-of-file, so we do too.
73 		 */
74 		if (db_get(sp, from, 0, &p, &len)) {
75 			cmdp->addr2.lno = from - 1;
76 			break;
77 		}
78 
79 		/* Empty lines just go away. */
80 		if (len == 0)
81 			continue;
82 
83 		/*
84 		 * Get more space if necessary.  Note, tlen isn't the length
85 		 * of the new line, it's roughly the amount of space needed.
86 		 * tbp - bp is the length of the new line.
87 		 */
88 		tlen += len + 2;
89 		ADD_SPACE_RET(sp, bp, blen, tlen);
90 		tbp = bp + clen;
91 
92 		/*
93 		 * Historic practice:
94 		 *
95 		 * If force specified, join without modification.
96 		 * If the current line ends with whitespace, strip leading
97 		 *    whitespace from the joined line.
98 		 * If the next line starts with a ), do nothing.
99 		 * If the current line ends with ., insert two spaces.
100 		 * Else, insert one space.
101 		 *
102 		 * One change -- add ? and ! to the list of characters for
103 		 * which we insert two spaces.  I expect that POSIX 1003.2
104 		 * will require this as well.
105 		 *
106 		 * Echar is the last character in the last line joined.
107 		 */
108 		extra = 0;
109 		if (!first && !FL_ISSET(cmdp->iflags, E_C_FORCE)) {
110 			if (isblank(echar))
111 				for (; len && isblank(*p); --len, ++p);
112 			else if (p[0] != ')') {
113 				if (strchr(".?!", echar)) {
114 					*tbp++ = ' ';
115 					++clen;
116 					extra = 1;
117 				}
118 				*tbp++ = ' ';
119 				++clen;
120 				for (; len && isblank(*p); --len, ++p);
121 			}
122 		}
123 
124 		if (len != 0) {
125 			memcpy(tbp, p, len);
126 			tbp += len;
127 			clen += len;
128 			echar = p[len - 1];
129 		} else
130 			echar = ' ';
131 
132 		/*
133 		 * Historic practice for vi was to put the cursor at the first
134 		 * inserted whitespace character, if there was one, or the
135 		 * first character of the joined line, if there wasn't, or the
136 		 * last character of the line if joined to an empty line.  If
137 		 * a count was specified, the cursor was moved as described
138 		 * for the first line joined, ignoring subsequent lines.  If
139 		 * the join was a ':' command, the cursor was placed at the
140 		 * first non-blank character of the line unless the cursor was
141 		 * "attracted" to the end of line when the command was executed
142 		 * in which case it moved to the new end of line.  There are
143 		 * probably several more special cases, but frankly, my dear,
144 		 * I don't give a damn.  This implementation puts the cursor
145 		 * on the first inserted whitespace character, the first
146 		 * character of the joined line, or the last character of the
147 		 * line regardless.  Note, if the cursor isn't on the joined
148 		 * line (possible with : commands), it is reset to the starting
149 		 * line.
150 		 */
151 		if (first) {
152 			sp->cno = (tbp - bp) - (1 + extra);
153 			first = 0;
154 		} else
155 			sp->cno = (tbp - bp) - len - (1 + extra);
156 	}
157 	sp->lno = cmdp->addr1.lno;
158 
159 	/* Delete the joined lines. */
160         for (from = cmdp->addr1.lno, to = cmdp->addr2.lno; to > from; --to)
161 		if (db_delete(sp, to))
162 			goto err;
163 
164 	/* If the original line changed, reset it. */
165 	if (!first && db_set(sp, from, bp, tbp - bp)) {
166 err:		FREE_SPACE(sp, bp, blen);
167 		return (1);
168 	}
169 	FREE_SPACE(sp, bp, blen);
170 
171 	sp->rptlines[L_JOINED] += (cmdp->addr2.lno - cmdp->addr1.lno) + 1;
172 	return (0);
173 }
174