new.c: Order two return statements to match comment.

[nmh] / sbr / check_charset.c

diff --git a/sbr/check_charset.c b/sbr/check_charset.c
index b10cde34a6429a9edc92712c683d04229f1c8a33..71129fef4ecf76e73747911805a06ff89262a80c 100644 (file)
--- a/sbr/check_charset.c
+++ b/sbr/check_charset.c
@@ -1,6 +1,86 @@
-/* norm_charmap.c -- map locale's encoding to MIME charset.
+/* check_charset.c -- routines for character sets

  *
  *

- * The Single Unix Specification function nl_langinfo(CODESET)
+ * This code is Copyright (c) 2002, by the authors of nmh.  See the
+ * COPYRIGHT file in the root directory of the nmh distribution for
+ * complete copyright information.
+ */
+
+#include <h/mh.h>
+
+#include <string.h>
+#include <langinfo.h>
+
+static const char *norm_charmap(char *name);
+
+/*
+ * Get the current character set
+ */
+char *
+get_charset(void)
+{
+    return (char *)norm_charmap(nl_langinfo(CODESET));
+}
+
+
+/*
+ * Check if we can display a given character set natively.
+ * We are passed the length of the initial part of the
+ * string to check, since we want to allow the name of the
+ * character set to be a substring of a larger string.
+ */
+
+int
+check_charset (char *str, int len) 
+{
+    static char *mm_charset = NULL;
+    static char *alt_charset = NULL;
+    static int mm_len;
+    static int alt_len;
+
+    /* Cache the name of our default character set */
+    if (!mm_charset) {
+       if (!(mm_charset = get_charset ()))
+           mm_charset = "US-ASCII";
+       mm_len = strlen (mm_charset);
+
+       /* US-ASCII is a subset of the ISO-8859-X and UTF-8 character sets */
+       if (!strncasecmp("ISO-8859-", mm_charset, 9) ||
+               !strcasecmp("UTF-8", mm_charset)) {
+           alt_charset = "US-ASCII";
+           alt_len = strlen (alt_charset);
+       }
+    }
+
+    /* Check if character set is OK */
+    if ((len == mm_len) && !strncasecmp(str, mm_charset, mm_len))
+       return 1;
+    if (alt_charset && (len == alt_len) && !strncasecmp(str, alt_charset, alt_len))
+       return 1;
+
+    return 0;
+}
+
+
+/*
+ * Return the name of the character set we are
+ * using for 8bit text.
+ */
+char *
+write_charset_8bit (void)
+{
+    static char *mm_charset = NULL;
+
+    /*
+     * Cache the name of the character set to
+     * use for 8bit text.
+     */
+    if (!mm_charset && !(mm_charset = get_charset ()))
+           mm_charset = "x-unknown";
+
+    return mm_charset;
+}
+
+/* The Single Unix Specification function nl_langinfo(CODESET)

  * returns the name of the encoding used by the currently selected
  * locale:
  *
  * returns the name of the encoding used by the currently selected
  * locale:
  *


@@ -25,89 +105,80 @@
  *   http://www.cl.cam.ac.uk/~mgk25/ucs/norm_charmap.c
  */
 
  *   http://www.cl.cam.ac.uk/~mgk25/ucs/norm_charmap.c
  */
 

-#include <string.h>
+static const char *norm_charmap(char *name)
+{
+    static const char *correct[] = {
+        "UTF-8",
+        "US-ASCII",
+        NULL
+    }, **cor;
+    static struct {
+        const char *alias;
+        const char *name;
+    } *ali, aliases[] = {
+        /* Names for US-ASCII. */
+        { "ANSI_X3.4-1968", "US-ASCII" }, /* LC_ALL=C. */
+        { "ASCII", "US-ASCII" },
+        { "646", "US-ASCII" },
+        { "ISO646", "US-ASCII" },
+        { "ISO_646.IRV", "US-ASCII" },
+        /* Case differs. */
+        { "BIG5", "Big5" },
+        { "BIG5HKSCS", "Big5HKSCS" },
+        /* Names for ISO-8859-11. */
+        { "TIS-620", "ISO-8859-11" },
+        { "TIS620.2533", "ISO-8859-11" },
+        { NULL, NULL }
+    };
+    static struct {
+        const char *substr;
+        const char *name;
+    } *sub, substrs[] = {
+        { "8859-1", "ISO-8859-1" },
+        { "8859-2", "ISO-8859-2" },
+        { "8859-3", "ISO-8859-3" },
+        { "8859-4", "ISO-8859-4" },
+        { "8859-5", "ISO-8859-5" },
+        { "8859-6", "ISO-8859-6" },
+        { "8859-7", "ISO-8859-7" },
+        { "8859-8", "ISO-8859-8" },
+        { "8859-9", "ISO-8859-9" },
+        { "8859-10", "ISO-8859-10" },
+        { "8859-11", "ISO-8859-11" },
+        /* 12, Latin/Devanagari, not completed. */
+        { "8859-13", "ISO-8859-13" },
+        { "8859-14", "ISO-8859-14" },
+        { "8859-15", "ISO-8859-15" },
+        { "8859-16", "ISO-8859-16" },
+        { "CP1200", "WINDOWS-1200" },
+        { "CP1201", "WINDOWS-1201" },
+        { "CP1250", "WINDOWS-1250" },
+        { "CP1251", "WINDOWS-1251" },
+        { "CP1252", "WINDOWS-1252" },
+        { "CP1253", "WINDOWS-1253" },
+        { "CP1254", "WINDOWS-1254" },
+        { "CP1255", "WINDOWS-1255" },
+        { "CP1256", "WINDOWS-1256" },
+        { "CP1257", "WINDOWS-1257" },
+        { "CP1258", "WINDOWS-1258" },
+        { NULL, NULL }
+    };

 
 

-#define digit(x) ((x) >= '0' && (x) <= '9')
+    if (!name)
+        return name;

 
 

-static char buf[16];
+    /* Avoid lots of tests for common correct names. */
+    for (cor = correct; *cor; cor++)
+        if (!strcmp(name, *cor))
+            return name;
+
+    for (ali = aliases; ali->alias; ali++)
+        if (!strcmp(name, ali->alias))
+            return ali->name;
+
+    for (sub = substrs; sub->substr; sub++)
+        if (strstr(name, sub->substr))
+            return sub->name;

 
 

-char *
-norm_charmap(char *name)
-{
-  char *p;
-  
-  if (!name)

     return name;
     return name;

-  
-  /* Many need no remapping, but they are listed here so you
-   * can see what output to expect, and modify for your needs
-   * as necessary. */
-  if (!strcmp(name, "UTF-8"))
-    return "UTF-8";
-  if (!strcmp(name, "EUC-JP"))
-    return "EUC-JP";
-  if (!strcmp(name, "EUC-KR"))
-    return "EUC-KR";
-  if (!strcmp(name, "EUC-TW"))
-    return "EUC-TW";
-  if (!strcmp(name, "KOI8-R"))
-    return "KOI8-R";
-  if (!strcmp(name, "KOI8-U"))
-    return "KOI8-U";
-  if (!strcmp(name, "GBK"))
-    return "GBK";
-  if (!strcmp(name, "GB2312"))
-    return "GB2312";
-  if (!strcmp(name, "GB18030"))
-    return "GB18030";
-  if (!strcmp(name, "VSCII"))
-    return "VSCII";
-  
-  /* ASCII comes in many names */
-  if (!strcmp(name, "ASCII") ||
-      !strcmp(name, "US-ASCII") ||
-      !strcmp(name, "ANSI_X3.4-1968") ||
-      !strcmp(name, "646") ||
-      !strcmp(name, "ISO646") ||
-      !strcmp(name, "ISO_646.IRV"))
-    return "US-ASCII";
-
-  /* ISO 8859 will be converted to "ISO-8859-x" */
-  if ((p = strstr(name, "8859-"))) {
-    memcpy(buf, "ISO-8859-\0\0", 12);
-    p += 5;
-    if (digit(*p)) {
-      buf[9] = *p++;
-      if (digit(*p)) buf[10] = *p++;
-      return buf;
-    }
-  }
-
-  /* Windows code pages will be converted to "WINDOWS-12xx" */
-  if ((p = strstr(name, "CP12"))) {
-    memcpy(buf, "WINDOWS-12\0\0", 13);
-    p += 4;
-    if (digit(*p)) {
-      buf[10] = *p++;
-      if (digit(*p)) buf[11] = *p++;
-      return buf;
-    }
-  }
-
-  /* TIS-620 comes in at least the following two forms */
-  if (!strcmp(name, "TIS-620") ||
-      !strcmp(name, "TIS620.2533"))
-    return "ISO-8859-11";
-
-  /* For some, uppercase/lowercase might differ */
-  if (!strcmp(name, "Big5") || !strcmp(name, "BIG5"))
-    return "Big5";
-  if (!strcmp(name, "Big5HKSCS") || !strcmp(name, "BIG5HKSCS"))
-    return "Big5HKSCS";
-
-  /* I don't know of any implementation of nl_langinfo(CODESET) out
-   * there that returns anything else (and I'm not even certain all of
-   * the above occur in the wild), but just in case, as a fallback,
-   * return the unmodified name. */
-  return name;

 }
 }