diff options
Diffstat (limited to 'wcsmbs/mbrtowc.c')
| -rw-r--r-- | wcsmbs/mbrtowc.c | 111 |
1 files changed, 88 insertions, 23 deletions
diff --git a/wcsmbs/mbrtowc.c b/wcsmbs/mbrtowc.c index 2c4b0779da..9e70a0b2c9 100644 --- a/wcsmbs/mbrtowc.c +++ b/wcsmbs/mbrtowc.c @@ -1,6 +1,6 @@ /* Copyright (C) 1996 Free Software Foundation, Inc. This file is part of the GNU C Library. -Contributed by Ulrich Drepper, <drepper@gnu.ai.mit.edu> +Contributed by Ulrich Drepper <drepper@gnu.ai.mit.edu>, 1996. The GNU C Library is free software; you can redistribute it and/or modify it under the terms of the GNU Library General Public License as @@ -17,50 +17,115 @@ License along with the GNU C Library; see the file COPYING.LIB. If not, write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */ +#include <errno.h> #include <wchar.h> +#ifndef EILSEQ +#define EILSEQ EINVAL +#endif + static mbstate_t internal; size_t -mbrtowc (pwc, s, n, ps) - wchar_t *pwc; - const char *s; - size_t n; - mbstate_t *ps; +mbrtowc (wchar_t *pwc, const char *s, size_t n, mbstate_t *ps) { wchar_t to_wide; + size_t used = 0; if (ps == NULL) ps = &internal; - /*************************************************************\ - |* This is no complete implementation. While the multi-byte *| - |* character handling is not finished this will do. *| - \*************************************************************/ - if (s == NULL) { + /* See first paragraph of description in 7.16.6.3.2. */ pwc = NULL; s = ""; n = 1; } - if (n == 0) - return (size_t) -2; + if (n > 0) + { + if (ps->count == 0) + { + unsigned char byte = (unsigned char) *s++; + ++used; - /* For now. */ - to_wide = (wchar_t) *s; + /* We must look for a possible first byte of a UTF8 sequence. */ + if (byte < 0x80) + { + /* One byte sequence. */ + if (pwc != NULL) + *pwc = (wchar_t) byte; + return byte ? used : 0; + } - if (pwc != NULL) - *pwc = to_wide; + if ((byte & 0xc0) == 0x80 || (byte & 0xfe) == 0xfe) + { + /* Oh, oh. An encoding error. */ + errno = EILSEQ; + return (size_t) -1; + } - if (pwc == L'\0') - { - *ps = 0; /* This is required. */ - return 0; + if ((byte & 0xe0) == 0xc0) + { + /* We expect two bytes. */ + ps->count = 1; + ps->value = byte & 0x1f; + } + else if ((byte & 0xf0) == 0xe0) + { + /* We expect three bytes. */ + ps->count = 2; + ps->value = byte & 0x0f; + } + else if ((byte & 0xf8) == 0xf0) + { + /* We expect four bytes. */ + ps->count = 3; + ps->value = byte & 0x07; + } + else if ((byte & 0xfc) == 0xf8) + { + /* We expect five bytes. */ + ps->count = 4; + ps->value = byte & 0x03; + } + else + { + /* We expect six bytes. */ + ps->count = 5; + ps->value = byte & 0x01; + } + } + + /* We know we have to handle a multibyte character and there are + some more bytes to read. */ + while (used < n) + { + /* The second to sixths byte must be of the form 10xxxxxx. */ + unsigned char byte = (unsigned char) *s++; + ++used; + + if ((byte & 0xc0) != 0x80) + { + /* Oh, oh. An encoding error. */ + errno = EILSEQ; + return (size_t) -1; + } + + ps->value <<= 6; + ps->value |= byte & 0x3f; + + if (--ps->count == 0) + { + /* The character is finished. */ + if (pwc != NULL) + *pwc = (wchar_t) ps->value; + return ps->value ? used : 0; + } + } } - /* Return code (size_t)-1 cannot happend for now. */ - return 1; + return (size_t) -2; } |