added simplified Unicode support for non-locale-enabled builds

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

1 files changed, 241 insertions, 0 deletions

diff --git a/libbb/unicode.c b/libbb/unicode.c
new file mode 100644
index 000000000..a99f5ede1
--- /dev/null
+++ b/libbb/unicode.c
@@ -0,0 +1,241 @@
+/* vi: set sw=4 ts=4: */
+/*
+ * Unicode support routines.
+ *
+ * Copyright (C) 2008 Denys Vlasenko
+ *
+ * Licensed under GPL version 2, see file LICENSE in this tarball for details.
+ */
+#include "libbb.h"
+
+/* if LOCALE_SUPPORT, libc locale stuff takes care of it, else: */
+
+#if !ENABLE_LOCALE_SUPPORT
+#include "unicode.h"
+
+/* 0: not known yet,
+ * 1: not unicode (IOW: assuming one char == one byte)
+ * 2: unicode
+ */
+# if !ENABLE_FEATURE_CHECK_UNICODE_IN_ENV
+#  define unicode_is_enabled 2
+# else
+static smallint unicode_is_enabled;
+void FAST_FUNC check_unicode_in_env(void)
+{
+        char *lang;
+
+        if (unicode_is_enabled)
+                return;
+        unicode_is_enabled = 1;
+
+        lang = getenv("LANG");
+        if (!lang || !strstr(lang, ".utf8"))
+                return;
+
+        unicode_is_enabled = 2;
+}
+# endif
+
+static size_t wcrtomb_internal(char *s, wchar_t wc)
+{
+        uint32_t v = wc;
+
+        if (v <= 0x7f) {
+                *s = v;
+                return 1;
+        }
+
+        /* 80-7FF -> 110yyyxx 10xxxxxx */
+        if (v <= 0x7ff) {
+                s[1] = (v & 0x3f) | 0x80;
+                v >>= 6;
+                s[0] = v | 0xc0;
+                return 2;
+        }
+
+        /* 800-FFFF -> 1110yyyy 10yyyyxx 10xxxxxx */
+        if (v <= 0xffff) {
+                s[2] = (v & 0x3f) | 0x80;
+                v >>= 6;
+                s[1] = (v & 0x3f) | 0x80;
+                v >>= 6;
+                s[0] = v | 0xe0;
+                return 3;
+        }
+
+        /* RFC 3629 says that Unicode ends at 10FFFF */
+
+        /* 10000-1FFFFF -> 11110zzz 10zzyyyy 10yyyyxx 10xxxxxx */
+        if (v <= 0x1fffff) {
+                s[3] = (v & 0x3f) | 0x80;
+                v >>= 6;
+                s[2] = (v & 0x3f) | 0x80;
+                v >>= 6;
+                s[1] = (v & 0x3f) | 0x80;
+                v >>= 6;
+                s[0] = v | 0xf0;
+                return 4;
+        }
+
+        /* 200000-3FFFFFF -> 111110tt 10zzzzzz 10zzyyyy 10yyyyxx 10xxxxxx */
+        if (v <= 0x3ffffff) {
+                s[4] = (v & 0x3f) | 0x80;
+                v >>= 6;
+                s[3] = (v & 0x3f) | 0x80;
+                v >>= 6;
+                s[2] = (v & 0x3f) | 0x80;
+                v >>= 6;
+                s[1] = (v & 0x3f) | 0x80;
+                v >>= 6;
+                s[0] = v | 0xf8;
+                return 5;
+        }
+
+        /* 4000000-FFFFFFFF -> 111111tt 10tttttt 10zzzzzz 10zzyyyy 10yyyyxx 10xxxxxx */
+        s[5] = (v & 0x3f) | 0x80;
+        v >>= 6;
+        s[4] = (v & 0x3f) | 0x80;
+        v >>= 6;
+        s[3] = (v & 0x3f) | 0x80;
+        v >>= 6;
+        s[2] = (v & 0x3f) | 0x80;
+        v >>= 6;
+        s[1] = (v & 0x3f) | 0x80;
+        v >>= 6;
+        s[0] = v | 0xfc;
+        return 6;
+}
+
+size_t FAST_FUNC wcrtomb(char *s, wchar_t wc, mbstate_t *ps UNUSED_PARAM)
+{
+        if (unicode_is_enabled != 2) {
+                *s = wc;
+                return 1;
+        }
+
+        return wcrtomb_internal(s, wc);
+}
+
+size_t FAST_FUNC wcstombs(char *dest, const wchar_t *src, size_t n)
+{
+        size_t org_n = n;
+
+        if (unicode_is_enabled != 2) {
+                while (n) {
+                        wchar_t c = *src++;
+                        *dest++ = c;
+                        if (c == 0)
+                                break;
+                        n--;
+                }
+                return org_n - n;
+        }
+
+        while (n >= MB_CUR_MAX) {
+                wchar_t wc = *src++;
+                size_t len = wcrtomb_internal(dest, wc);
+
+                if (wc == L'\0')
+                        return org_n - n;
+                dest += len;
+                n -= len;
+        }
+        while (n) {
+                char tbuf[MB_CUR_MAX];
+                wchar_t wc = *src++;
+                size_t len = wcrtomb_internal(tbuf, wc);
+
+                if (len > n)
+                        len = n;
+                memcpy(dest, tbuf, len);
+                if (wc == L'\0')
+                        return org_n - n;
+                dest += len;
+                n -= len;
+        }
+        return org_n - n;
+}
+
+size_t FAST_FUNC mbstowcs(wchar_t *dest, const char *src, size_t n)
+{
+        size_t org_n = n;
+
+        if (unicode_is_enabled != 2) {
+                while (n) {
+                        unsigned char c = *src++;
+                        *dest++ = c;
+                        if (c == 0)
+                                break;
+                        n--;
+                }
+                return org_n - n;
+        }
+
+        while (n) {
+                int bytes;
+                unsigned c = (unsigned char) *src++;
+
+                if (c <= 0x7f) {
+                        *dest++ = c;
+                        if (c == '\0')
+                                break;
+                        n--;
+                        continue;
+                }
+
+                /* 80-7FF -> 110yyyxx 10xxxxxx */
+                /* 800-FFFF -> 1110yyyy 10yyyyxx 10xxxxxx */
+                /* 10000-1FFFFF -> 11110zzz 10zzyyyy 10yyyyxx 10xxxxxx */
+                /* 200000-3FFFFFF -> 111110tt 10zzzzzz 10zzyyyy 10yyyyxx 10xxxxxx */
+                /* 4000000-FFFFFFFF -> 111111tt 10tttttt 10zzzzzz 10zzyyyy 10yyyyxx 10xxxxxx */
+                bytes = 0;
+                do {
+                        c <<= 1;
+                        bytes++;
+                } while ((c & 0x80) && bytes < 6);
+                if (bytes == 1)
+                        return (size_t) -1L;
+                c = (uint8_t)(c) >> bytes;
+
+                while (--bytes) {
+                        unsigned ch = (unsigned char) *src++;
+                        if ((ch & 0xc0) != 0x80) {
+                                return (size_t) -1L;
+                        }
+                        c = (c << 6) + (ch & 0x3f);
+                }
+
+                /* TODO */
+                /* Need to check that c isn't produced by overlong encoding */
+                /* Example: 11000000 10000000 converts to NUL */
+                /* 11110000 10000000 10000100 10000000 converts to 0x100 */
+                /* correct encoding: 11000100 10000000 */
+                if (c <= 0x7f) { /* crude check */
+                        return (size_t) -1L;
+                        //or maybe: c = 0xfffd; /* replacement character */
+                }
+
+                *dest++ = c;
+                n--;
+        }
+
+        return org_n - n;
+}
+
+int FAST_FUNC iswspace(wint_t wc)
+{
+        return (unsigned)wc <= 0x7f && isspace(wc);
+}
+
+int FAST_FUNC iswalnum(wint_t wc)
+{
+        return (unsigned)wc <= 0x7f && isalnum(wc);
+}
+
+int FAST_FUNC iswpunct(wint_t wc)
+{
+        return (unsigned)wc <= 0x7f && ispunct(wc);
+}
+
+#endif