1 /* 2 * Copyright (C) 1984-2022 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 */ 22 public int 23 cvt_length(len, ops) 24 int len; 25 int ops; 26 { 27 if (utf_mode) 28 /* 29 * Just copying a string in UTF-8 mode can cause it to grow 30 * in length. 31 * Four output bytes for one input byte is the worst case. 32 */ 33 len *= 4; 34 return (len + 1); 35 } 36 37 /* 38 * Allocate a chpos array for use by cvt_text. 39 */ 40 public int * 41 cvt_alloc_chpos(len) 42 int len; 43 { 44 int i; 45 int *chpos = (int *) ecalloc(sizeof(int), len); 46 /* Initialize all entries to an invalid position. */ 47 for (i = 0; i < len; i++) 48 chpos[i] = -1; 49 return (chpos); 50 } 51 52 /* 53 * Convert text. Perform the transformations specified by ops. 54 * Returns converted text in odst. The original offset of each 55 * odst character (when it was in osrc) is returned in the chpos array. 56 */ 57 public void 58 cvt_text(odst, osrc, chpos, lenp, ops) 59 char *odst; 60 char *osrc; 61 int *chpos; 62 int *lenp; 63 int ops; 64 { 65 char *dst; 66 char *edst = odst; 67 char *src; 68 char *src_end; 69 LWCHAR ch; 70 71 if (lenp != NULL) 72 src_end = osrc + *lenp; 73 else 74 src_end = osrc + strlen(osrc); 75 76 for (src = osrc, dst = odst; src < src_end; ) 77 { 78 int src_pos = (int) (src - osrc); 79 int dst_pos = (int) (dst - odst); 80 struct ansi_state *pansi; 81 ch = step_char(&src, +1, src_end); 82 if ((ops & CVT_BS) && ch == '\b' && dst > odst) 83 { 84 /* Delete backspace and preceding char. */ 85 do { 86 dst--; 87 } while (dst > odst && utf_mode && 88 !IS_ASCII_OCTET(*dst) && !IS_UTF8_LEAD(*dst)); 89 } else if ((ops & CVT_ANSI) && (pansi = ansi_start(ch)) != NULL) 90 { 91 /* Skip to end of ANSI escape sequence. */ 92 while (src < src_end) 93 { 94 if (ansi_step(pansi, ch) != ANSI_MID) 95 break; 96 ch = *src++; 97 } 98 ansi_done(pansi); 99 } else 100 { 101 /* Just copy the char to the destination buffer. */ 102 if ((ops & CVT_TO_LC) && IS_UPPER(ch)) 103 ch = TO_LOWER(ch); 104 put_wchar(&dst, ch); 105 /* Record the original position of the char. */ 106 if (chpos != NULL) 107 chpos[dst_pos] = src_pos; 108 } 109 if (dst > edst) 110 edst = dst; 111 } 112 if ((ops & CVT_CRLF) && edst > odst && edst[-1] == '\r') 113 edst--; 114 *edst = '\0'; 115 if (lenp != NULL) 116 *lenp = (int) (edst - odst); 117 /* FIXME: why was this here? if (chpos != NULL) chpos[dst - odst] = src - osrc; */ 118 } 119