IABSD.fr/src/usr.bin/less/cvt.c

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• Author : schwarze
  Date : 2019-05-15 19:06:01
  Hash : fcc1e361
  Message : trivial replacement of the home-grown IS_ASCII_OCTET() with the standard isascii(3)

• usr.bin/less/cvt.c

• /*
   * Copyright (C) 1984-2012  Mark Nudelman
   * Modified for use with illumos by Garrett D'Amore.
   * Copyright 2014 Garrett D'Amore <garrett@damore.org>
   *
   * You may distribute under the terms of either the GNU General Public
   * License or the Less License, as specified in the README file.
   *
   * For more information, see the README file.
   */
  
  /*
   * Routines to convert text in various ways.  Used by search.
   */
  
  #include "charset.h"
  #include "less.h"
  
  extern int utf_mode;
  
  /*
   * Get the length of a buffer needed to convert a string.
   */
  int
  cvt_length(int len)
  {
  	if (utf_mode)
  		/*
  		 * Just copying a string in UTF-8 mode can cause it to grow
  		 * in length.
  		 * Four output bytes for one input byte is the worst case.
  		 */
  		len *= 4;
  	return (len + 1);
  }
  
  /*
   * Allocate a chpos array for use by cvt_text.
   */
  int *
  cvt_alloc_chpos(int len)
  {
  	int i;
  	int *chpos = ecalloc(sizeof (int), len);
  	/* Initialize all entries to an invalid position. */
  	for (i = 0; i < len; i++)
  		chpos[i] = -1;
  	return (chpos);
  }
  
  /*
   * Convert text.  Perform the transformations specified by ops.
   * Returns converted text in odst.  The original offset of each
   * odst character (when it was in osrc) is returned in the chpos array.
   */
  void
  cvt_text(char *odst, char *osrc, int *chpos, int *lenp, int ops)
  {
  	char *dst;
  	char *edst = odst;
  	char *src;
  	char *src_end;
  	wchar_t ch;
  	int len;
  
  	if (lenp != NULL)
  		src_end = osrc + *lenp;
  	else
  		src_end = osrc + strlen(osrc);
  
  	for (src = osrc, dst = odst; src < src_end; ) {
  		int src_pos = src - osrc;
  		int dst_pos = dst - odst;
  		if ((len = mbtowc(&ch, src, src_end - src)) < 1)
  			ch = L'\0';
  		if ((ops & CVT_BS) && ch == '\b' && dst > odst) {
  			src++;
  			/* Delete backspace and preceding char. */
  			do {
  				dst--;
  			} while (dst > odst && IS_UTF8_TRAIL(*dst));
  		} else if ((ops & CVT_ANSI) && ch == ESC) {
  			/* Skip to end of ANSI escape sequence. */
  			src++;	/* skip the CSI start char */
  			while (src < src_end)
  				if (!is_ansi_middle(*src++))
  					break;
  		} else if (len < 1) {
  			*dst++ = *src++;
  			if (chpos != NULL)
  				chpos[dst_pos] = src_pos;
  		} else {
  			src += len;
  			/* Just copy the char to the destination buffer. */
  			if ((ops & CVT_TO_LC) && iswupper(ch))
  				ch = towlower(ch);
  			dst += wctomb(dst, ch);
  			/* Record the original position of the char. */
  			if (chpos != NULL)
  				chpos[dst_pos] = src_pos;
  		}
  		if (dst > edst)
  			edst = dst;
  	}
  	if ((ops & CVT_CRLF) && edst > odst && edst[-1] == '\r')
  		edst--;
  	*edst = '\0';
  	if (lenp != NULL)
  		*lenp = edst - odst;
  }