1 /*
2 * Copyright (C) 1984-2023 Mark Nudelman
3 *
4 * You may distribute under the terms of either the GNU General Public
5 * License or the Less License, as specified in the README file.
6 *
7 * For more information, see the README file.
8 */
9
10 /*
11 * Routines to convert text in various ways. Used by search.
12 */
13
14 #include "less.h"
15 #include "charset.h"
16
17 extern int utf_mode;
18
19 /*
20 * Get the length of a buffer needed to convert a string.
21 */
cvt_length(int len,int ops)22 public int cvt_length(int len, int ops)
23 {
24 if (utf_mode)
25 /*
26 * Just copying a string in UTF-8 mode can cause it to grow
27 * in length.
28 * Four output bytes for one input byte is the worst case.
29 */
30 len *= 4;
31 return (len + 1);
32 }
33
34 /*
35 * Allocate a chpos array for use by cvt_text.
36 */
cvt_alloc_chpos(int len)37 public int * cvt_alloc_chpos(int len)
38 {
39 int i;
40 int *chpos = (int *) ecalloc(sizeof(int), len);
41 /* Initialize all entries to an invalid position. */
42 for (i = 0; i < len; i++)
43 chpos[i] = -1;
44 return (chpos);
45 }
46
47 /*
48 * Convert text. Perform the transformations specified by ops.
49 * Returns converted text in odst. The original offset of each
50 * odst character (when it was in osrc) is returned in the chpos array.
51 */
cvt_text(char * odst,char * osrc,int * chpos,int * lenp,int ops)52 public void cvt_text(char *odst, char *osrc, int *chpos, int *lenp, int ops)
53 {
54 char *dst;
55 char *edst = odst;
56 char *src;
57 char *src_end;
58 LWCHAR ch;
59
60 if (lenp != NULL)
61 src_end = osrc + *lenp;
62 else
63 src_end = osrc + strlen(osrc);
64
65 for (src = osrc, dst = odst; src < src_end; )
66 {
67 int src_pos = (int) (src - osrc);
68 int dst_pos = (int) (dst - odst);
69 struct ansi_state *pansi;
70 ch = step_char(&src, +1, src_end);
71 if ((ops & CVT_BS) && ch == '\b' && dst > odst)
72 {
73 /* Delete backspace and preceding char. */
74 do {
75 dst--;
76 } while (dst > odst && utf_mode &&
77 !IS_ASCII_OCTET(*dst) && !IS_UTF8_LEAD(*dst));
78 } else if ((ops & CVT_ANSI) && (pansi = ansi_start(ch)) != NULL)
79 {
80 /* Skip to end of ANSI escape sequence. */
81 while (src < src_end)
82 {
83 if (ansi_step(pansi, ch) != ANSI_MID)
84 break;
85 ch = *src++;
86 }
87 ansi_done(pansi);
88 } else
89 {
90 /* Just copy the char to the destination buffer. */
91 if ((ops & CVT_TO_LC) && IS_UPPER(ch))
92 ch = TO_LOWER(ch);
93 put_wchar(&dst, ch);
94 /* Record the original position of the char. */
95 if (chpos != NULL)
96 chpos[dst_pos] = src_pos;
97 }
98 if (dst > edst)
99 edst = dst;
100 }
101 if ((ops & CVT_CRLF) && edst > odst && edst[-1] == '\r')
102 edst--;
103 *edst = '\0';
104 if (lenp != NULL)
105 *lenp = (int) (edst - odst);
106 /* FIXME: why was this here? if (chpos != NULL) chpos[dst - odst] = src - osrc; */
107 }
108