2 * Copyright (C) 1984-2011 Mark Nudelman
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.
7 * For more information about less, or for information on how to
8 * contact the author, see the README file.
12 * Routines to convert text in various ways. Used by search.
21 * Get the length of a buffer needed to convert a string.
30 * Just copying a string in UTF-8 mode can cause it to grow
32 * Four output bytes for one input byte is the worst case.
39 * Allocate a chpos array for use by cvt_text.
46 int *chpos = (int *) ecalloc(sizeof(int), len);
47 /* Initialize all entries to an invalid position. */
48 for (i = 0; i < len; i++)
54 * Convert text. Perform the transformations specified by ops.
55 * Returns converted text in odst. The original offset of each
56 * odst character (when it was in osrc) is returned in the chpos array.
59 cvt_text(odst, osrc, chpos, lenp, ops)
68 register char *src_end;
72 src_end = osrc + *lenp;
74 src_end = osrc + strlen(osrc);
76 for (src = osrc, dst = odst; src < src_end; )
78 int src_pos = src - osrc;
79 int dst_pos = dst - odst;
80 ch = step_char(&src, +1, src_end);
81 if ((ops & CVT_BS) && ch == '\b' && dst > odst)
83 /* Delete backspace and preceding char. */
86 } while (dst > odst &&
87 !IS_ASCII_OCTET(*dst) && !IS_UTF8_LEAD(*dst));
88 } else if ((ops & CVT_ANSI) && IS_CSI_START(ch))
90 /* Skip to end of ANSI escape sequence. */
91 src++; /* skip the CSI start char */
93 if (!is_ansi_middle(*src++))
97 /* Just copy the char to the destination buffer. */
98 if ((ops & CVT_TO_LC) && IS_UPPER(ch))
102 * Record the original position of the char.
103 * But if we've already recorded a position
104 * for this char (due to a backspace), leave
105 * it alone; if multiple source chars map to
106 * one destination char, we want the position
109 if (chpos != NULL && chpos[dst_pos] < 0)
110 chpos[dst_pos] = src_pos;
113 if ((ops & CVT_CRLF) && dst > odst && dst[-1] == '\r')
119 chpos[dst - odst] = src - osrc;