1 /* 2 * Copyright (C) 1984-2019 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 ch = step_char(&src, +1, src_end); 81 if ((ops & CVT_BS) && ch == '\b' && dst > odst) 82 { 83 /* Delete backspace and preceding char. */ 84 do { 85 dst--; 86 } while (dst > odst && utf_mode && 87 !IS_ASCII_OCTET(*dst) && !IS_UTF8_LEAD(*dst)); 88 } else if ((ops & CVT_ANSI) && IS_CSI_START(ch)) 89 { 90 /* Skip to end of ANSI escape sequence. */ 91 src++; /* skip the CSI start char */ 92 while (src < src_end) 93 if (!is_ansi_middle(*src++)) 94 break; 95 } else 96 { 97 /* Just copy the char to the destination buffer. */ 98 if ((ops & CVT_TO_LC) && IS_UPPER(ch)) 99 ch = TO_LOWER(ch); 100 put_wchar(&dst, ch); 101 /* Record the original position of the char. */ 102 if (chpos != NULL) 103 chpos[dst_pos] = src_pos; 104 } 105 if (dst > edst) 106 edst = dst; 107 } 108 if ((ops & CVT_CRLF) && edst > odst && edst[-1] == '\r') 109 edst--; 110 *edst = '\0'; 111 if (lenp != NULL) 112 *lenp = (int) (edst - odst); 113 /* FIXME: why was this here? if (chpos != NULL) chpos[dst - odst] = src - osrc; */ 114 } 115