1 /* $NetBSD: cvt.c,v 1.3 2013/09/04 19:44:21 tron Exp $ */
2
3 /*
4 * Copyright (C) 1984-2012 Mark Nudelman
5 *
6 * You may distribute under the terms of either the GNU General Public
7 * License or the Less License, as specified in the README file.
8 *
9 * For more information, see the README file.
10 */
11
12 /*
13 * Routines to convert text in various ways. Used by search.
14 */
15
16 #include "less.h"
17 #include "charset.h"
18
19 extern int utf_mode;
20
21 /*
22 * Get the length of a buffer needed to convert a string.
23 */
24 public int
cvt_length(len,ops)25 cvt_length(len, ops)
26 int len;
27 int ops;
28 {
29 if (utf_mode)
30 /*
31 * Just copying a string in UTF-8 mode can cause it to grow
32 * in length.
33 * Four output bytes for one input byte is the worst case.
34 */
35 len *= 4;
36 return (len + 1);
37 }
38
39 /*
40 * Allocate a chpos array for use by cvt_text.
41 */
42 public int *
cvt_alloc_chpos(len)43 cvt_alloc_chpos(len)
44 int len;
45 {
46 int i;
47 int *chpos = (int *) ecalloc(sizeof(int), len);
48 /* Initialize all entries to an invalid position. */
49 for (i = 0; i < len; i++)
50 chpos[i] = -1;
51 return (chpos);
52 }
53
54 /*
55 * Convert text. Perform the transformations specified by ops.
56 * Returns converted text in odst. The original offset of each
57 * odst character (when it was in osrc) is returned in the chpos array.
58 */
59 public void
cvt_text(odst,osrc,chpos,lenp,ops)60 cvt_text(odst, osrc, chpos, lenp, ops)
61 char *odst;
62 char *osrc;
63 int *chpos;
64 int *lenp;
65 int ops;
66 {
67 char *dst;
68 char *edst = odst;
69 char *src;
70 register char *src_end;
71 LWCHAR ch;
72
73 if (lenp != NULL)
74 src_end = osrc + *lenp;
75 else
76 src_end = osrc + strlen(osrc);
77
78 for (src = osrc, dst = odst; src < src_end; )
79 {
80 int src_pos = src - osrc;
81 int dst_pos = dst - odst;
82 ch = step_char(&src, +1, src_end);
83 if ((ops & CVT_BS) && ch == '\b' && dst > odst)
84 {
85 /* Delete backspace and preceding char. */
86 do {
87 dst--;
88 } while (dst > odst &&
89 !IS_ASCII_OCTET(*dst) && !IS_UTF8_LEAD(*dst));
90 } else if ((ops & CVT_ANSI) && IS_CSI_START(ch))
91 {
92 /* Skip to end of ANSI escape sequence. */
93 src++; /* skip the CSI start char */
94 while (src < src_end)
95 if (!is_ansi_middle(*src++))
96 break;
97 } else
98 {
99 /* Just copy the char to the destination buffer. */
100 if ((ops & CVT_TO_LC) && IS_UPPER(ch))
101 ch = TO_LOWER(ch);
102 put_wchar(&dst, ch);
103 /* Record the original position of the char. */
104 if (chpos != NULL)
105 chpos[dst_pos] = src_pos;
106 }
107 if (dst > edst)
108 edst = dst;
109 }
110 if ((ops & CVT_CRLF) && edst > odst && edst[-1] == '\r')
111 edst--;
112 *edst = '\0';
113 if (lenp != NULL)
114 *lenp = edst - odst;
115 /* FIXME: why was this here? if (chpos != NULL) chpos[dst - odst] = src - osrc; */
116 }
117