libgrapheme

Freestanding C library for unicode string handling
git clone https://git.sinitax.com/suckless/libgrapheme
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grapheme_encode_utf8.sh (1915B)

      1cat << EOF
      2.Dd ${MAN_DATE}
      3.Dt GRAPHEME_ENCODE_UTF8 3
      4.Os suckless.org
      5.Sh NAME
      6.Nm grapheme_encode_utf8
      7.Nd encode codepoint into UTF-8 string
      8.Sh SYNOPSIS
      9.In grapheme.h
     10.Ft size_t
     11.Fn grapheme_encode_utf8 "uint_least32_t cp" "char *str" "size_t len"
     12.Sh DESCRIPTION
     13The
     14.Fn grapheme_encode_utf8
     15function encodes the codepoint
     16.Va cp
     17into a UTF-8-string.
     18If
     19.Va str
     20is not
     21.Dv NULL
     22and
     23.Va len
     24is large enough it writes the UTF-8-string to the memory pointed to by
     25.Va str .
     26Otherwise no data is written.
     27.Sh RETURN VALUES
     28The
     29.Fn grapheme_encode_utf8
     30function returns the length (in bytes) of the UTF-8-string resulting
     31from encoding
     32.Va cp ,
     33even if
     34.Va len
     35is not large enough or
     36.Va str
     37is
     38.Dv NULL .
     39.Sh EXAMPLES
     40.Bd -literal
     41/* cc (-static) -o example example.c -lgrapheme */
     42#include <grapheme.h>
     43#include <stddef.h>
     44#include <stdlib.h>
     45
     46size_t
     47cps_to_utf8(const uint_least32_t *cp, size_t cplen, char *str, size_t len)
     48{
     49	size_t i, off, ret;
     50
     51	for (i = 0, off = 0; i < cplen; i++, off += ret) {
     52		if ((ret = grapheme_encode_utf8(cp[i], str + off,
     53		                                len - off)) > (len - off)) {
     54			/* buffer too small */
     55			break;
     56		}
     57	}
     58
     59	return off;
     60}
     61
     62size_t
     63cps_bytelen(const uint_least32_t *cp, size_t cplen)
     64{
     65	size_t i, len;
     66
     67	for (i = 0, len = 0; i < cplen; i++) {
     68		len += grapheme_encode_utf8(cp[i], NULL, 0);
     69	}
     70
     71	return len;
     72}
     73
     74char *
     75cps_to_utf8_alloc(const uint_least32_t *cp, size_t cplen)
     76{
     77	char *str;
     78	size_t len, i, ret, off;
     79
     80	len = cps_bytelen(cp, cplen);
     81
     82	if (!(str = malloc(len))) {
     83		return NULL;
     84	}
     85
     86	for (i = 0, off = 0; i < cplen; i++, off += ret) {
     87		if ((ret = grapheme_encode_utf8(cp[i], str + off,
     88		                                len - off)) > (len - off)) {
     89			/* buffer too small */
     90			break;
     91		}
     92	}
     93	str[off] = '\\\\0';
     94
     95	return str;
     96}
     97.Ed
     98.Sh SEE ALSO
     99.Xr grapheme_decode_utf8 3 ,
    100.Xr libgrapheme 7
    101.Sh AUTHORS
    102.An Laslo Hunhold Aq Mt dev@frign.de
    103EOF