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 */ 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 */ 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 */ 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