1 /* 2 * Copyright (C) 1984-2015 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(int len, int ops) 24 { 25 if (utf_mode) 26 /* 27 * Just copying a string in UTF-8 mode can cause it to grow 28 * in length. 29 * Four output bytes for one input byte is the worst case. 30 */ 31 len *= 4; 32 return (len + 1); 33 } 34 35 /* 36 * Allocate a chpos array for use by cvt_text. 37 */ 38 public int * 39 cvt_alloc_chpos(int len) 40 { 41 int i; 42 int *chpos = (int *) ecalloc(sizeof(int), len); 43 /* Initialize all entries to an invalid position. */ 44 for (i = 0; i < len; i++) 45 chpos[i] = -1; 46 return (chpos); 47 } 48 49 /* 50 * Convert text. Perform the transformations specified by ops. 51 * Returns converted text in odst. The original offset of each 52 * odst character (when it was in osrc) is returned in the chpos array. 53 */ 54 public void 55 cvt_text(char *odst, char *osrc, int *chpos, int *lenp, int ops) 56 { 57 char *dst; 58 char *edst = odst; 59 char *src; 60 char *src_end; 61 LWCHAR ch; 62 63 if (lenp != NULL) 64 src_end = osrc + *lenp; 65 else 66 src_end = osrc + strlen(osrc); 67 68 for (src = osrc, dst = odst; src < src_end; ) 69 { 70 int src_pos = (int) (src - osrc); 71 int dst_pos = (int) (dst - odst); 72 ch = step_char((constant char **)&src, +1, src_end); 73 if ((ops & CVT_BS) && ch == '\b' && dst > odst) 74 { 75 /* Delete backspace and preceding char. */ 76 do { 77 dst--; 78 } while (dst > odst && 79 !IS_ASCII_OCTET(*dst) && !IS_UTF8_LEAD(*dst)); 80 } else if ((ops & CVT_ANSI) && IS_CSI_START(ch)) 81 { 82 /* Skip to end of ANSI escape sequence. */ 83 src++; /* skip the CSI start char */ 84 while (src < src_end) 85 if (!is_ansi_middle(*src++)) 86 break; 87 } else 88 { 89 /* Just copy the char to the destination buffer. */ 90 if ((ops & CVT_TO_LC) && IS_UPPER(ch)) 91 ch = TO_LOWER(ch); 92 put_wchar(&dst, ch); 93 /* Record the original position of the char. */ 94 if (chpos != NULL) 95 chpos[dst_pos] = src_pos; 96 } 97 if (dst > edst) 98 edst = dst; 99 } 100 if ((ops & CVT_CRLF) && edst > odst && edst[-1] == '\r') 101 edst--; 102 *edst = '\0'; 103 if (lenp != NULL) 104 *lenp = (int) (edst - odst); 105 /* FIXME: why was this here? if (chpos != NULL) chpos[dst - odst] = src - osrc; */ 106 } 107