From e19f3d5e8c0e9576a3fda2b77ad69be135bef047 Mon Sep 17 00:00:00 2001 From: Mattias Andrée Date: Mon, 5 Nov 2018 18:54:48 +0100 Subject: Rename isutf8 to strisutf8 and add man page MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Signed-off-by: Mattias Andrée --- strisutf8.c | 136 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 136 insertions(+) create mode 100644 strisutf8.c (limited to 'strisutf8.c') diff --git a/strisutf8.c b/strisutf8.c new file mode 100644 index 0000000..ac4d0cb --- /dev/null +++ b/strisutf8.c @@ -0,0 +1,136 @@ +/* See LICENSE file for copyright and license details. */ +#include "libsimple.h" +#ifndef TEST + + +int +libsimple_strisutf8(const char *string, int allow_modified_nul) +{ + static long BYTES_TO_MIN_BITS[] = {0, 0, 8, 12, 17, 22, 27}; + static long BYTES_TO_MAX_BITS[] = {0, 7, 11, 16, 21, 26, 31}; + long int bytes = 0, read_bytes = 0, bits = 0, c, character; + + /* min bits max bits + 0....... 0 7 + 110..... 10...... 8 11 + 1110.... 10...... 10...... 12 16 + 11110... 10...... 10...... 10...... 17 21 + 111110.. 10...... 10...... 10...... 10...... 22 26 + 1111110. 10...... 10...... 10...... 10...... 10...... 27 31 + */ + + while ((c = (long int)(*string++))) { + if (!read_bytes) { + /* First byte of the character. */ + + if (!(c & 0x80)) + /* Single-byte character. */ + continue; + + if ((c & 0xC0) == 0x80) + /* Single-byte character marked as multibyte, or + a non-first byte in a multibyte character. */ + return 0; + + /* Multibyte character. */ + while ((c & 0x80)) + bytes++, c <<= 1; + read_bytes = 1; + character = (c & 0xFF) >> bytes; + if (bytes > 6) + /* 31-bit characters can be encoded with 6-bytes, + and UTF-8 does not cover higher code points. */ + return 0; + } else { + /* Not first byte of the character. */ + + if ((c & 0xC0) != 0x80) + /* Beginning of new character before a + multibyte character has ended. */ + return 0; + + character = (character << 6) | (c & 0x7F); + + if (++read_bytes < bytes) + /* Not at last byte yet. */ + continue; + + /* Check that the character is not unnecessarily long. */ + while (character) + character >>= 1, bits++; + bits = (!bits && bytes == 2 && allow_modified_nul) ? 8 : bits; + if (bits < BYTES_TO_MIN_BITS[bytes] || BYTES_TO_MAX_BITS[bytes] < bits) + return 0; + + read_bytes = bytes = bits = 0; + } + } + + /* Make sure we did not stop at the middle of a multibyte character. */ + return !read_bytes; +} + + +#else +#include "test.h" + +int +main(void) +{ + int i; + for (i = 0; i < 2; i++) { + assert(libsimple_strisutf8("", i) == 1); + assert(libsimple_strisutf8("a", i) == 1); + assert(libsimple_strisutf8("abc", i) == 1); + assert(libsimple_strisutf8("123", i) == 1); + assert(libsimple_strisutf8("åäö", i) == 1); + assert(libsimple_strisutf8("𝖆𝖇𝖈", i) == 1); + assert(libsimple_strisutf8("\x1b", i) == 1); + assert(libsimple_strisutf8("\n\r\t\f", i) == 1); + assert(libsimple_strisutf8("\xFF", i) == 0); + assert(libsimple_strisutf8("\x01", i) == 1); + assert(libsimple_strisutf8("\x7F", i) == 1); + assert(libsimple_strisutf8("\x80", i) == 0); + assert(libsimple_strisutf8("\xC0", i) == 0); + assert(libsimple_strisutf8("\xC0\x80", i) == i); + assert(libsimple_strisutf8("\xC0\x81", i) == 0); + assert(libsimple_strisutf8("\xCF", i) == 0); + assert(libsimple_strisutf8("\xEF", i) == 0); + assert(libsimple_strisutf8("\xEF\x8F", i) == 0); + assert(libsimple_strisutf8("\xF7", i) == 0); + assert(libsimple_strisutf8("\xF7\x8F", i) == 0); + assert(libsimple_strisutf8("\xF7\x8F\x8F", i) == 0); + assert(libsimple_strisutf8("\xFA", i) == 0); + assert(libsimple_strisutf8("\xFA\x8F", i) == 0); + assert(libsimple_strisutf8("\xFA\x8F\x8F", i) == 0); + assert(libsimple_strisutf8("\xFA\x8F\x8F\x8F", i) == 0); + assert(libsimple_strisutf8("\xFD", i) == 0); + assert(libsimple_strisutf8("\xFD\x8F", i) == 0); + assert(libsimple_strisutf8("\xFD\x8F\x8F", i) == 0); + assert(libsimple_strisutf8("\xFD\x8F\x8F\x8F", i) == 0); + assert(libsimple_strisutf8("\xFD\x8F\x8F\x8F\x8F", i) == 0); + assert(libsimple_strisutf8("\xFE", i) == 0); + assert(libsimple_strisutf8("\xFE\x8F", i) == 0); + assert(libsimple_strisutf8("\xFE\x8F\x8F", i) == 0); + assert(libsimple_strisutf8("\xFE\x8F\x8F\x8F", i) == 0); + assert(libsimple_strisutf8("\xFE\x8F\x8F\x8F\x8F", i) == 0); + assert(libsimple_strisutf8("\xFE\x8F\x8F\x8F\x8F\x8F", i) == 0); + assert(libsimple_strisutf8("\xFF", i) == 0); + assert(libsimple_strisutf8("\xFF\x8F", i) == 0); + assert(libsimple_strisutf8("\xFF\x8F\x8F", i) == 0); + assert(libsimple_strisutf8("\xFF\x8F\x8F\x8F", i) == 0); + assert(libsimple_strisutf8("\xFF\x8F\x8F\x8F\x8F", i) == 0); + assert(libsimple_strisutf8("\xFF\x8F\x8F\x8F\x8F\x8F", i) == 0); + assert(libsimple_strisutf8("\xFF\x8F\x8F\x8F\x8F\x8F\x8F", i) == 0); + assert(libsimple_strisutf8("\xC1\x80", i) == 0); + assert(libsimple_strisutf8("\xC2\x80", i) == 1); + assert(libsimple_strisutf8("\xE1\x80\x80\x80", i) == 0); + assert(libsimple_strisutf8("\xE1\x80\xC0\x80", i) == 0); + assert(libsimple_strisutf8("\xE1\x80\x00\x80", i) == 0); + assert(libsimple_strisutf8("\xF1\x80\x80\x80", i) == 1); + assert(libsimple_strisutf8("\xFF\x80\x80\x80\x80\x80\x80\x80", i) == 0); + } + return 0; +} + +#endif -- cgit v1.2.3-70-g09d2