New API functions iso_set_local_charset() and iso_get_local_charset()

libisofs/ecma119.c

@@ -911,9 +911,13 @@ int ecma119_image_new(IsoImage *src, IsoWriteOpts *opts, Ecma119Image **img)
     target->catalog = src->bootcat;
 
     /* default to locale charset */
+    /* ??? ts Nov 25 2008 :
+       Shouldn't this go to library initialization or even to app ?
+    */
     setlocale(LC_CTYPE, "");
 
-    target->input_charset = strdup(nl_langinfo(CODESET));
+    target->input_charset = strdup(iso_get_local_charset(0));
+
     if (target->input_charset == NULL) {
         iso_image_unref(src);
         free(target);

libisofs/fs_image.c

@@ -1996,8 +1996,12 @@ int iso_image_filesystem_new(IsoDataSource *src, struct iso_read_opts *opts,
     data->dir_mode = opts->dir_mode & ~S_IFMT;
     data->msgid = msgid;
 
+    /* ??? ts Nov 25 2008 :
+       Shouldn't this go to library initialization or even to app ?
+    */
     setlocale(LC_CTYPE, "");
-    data->local_charset = strdup(nl_langinfo(CODESET));
+
+    data->local_charset = strdup(iso_get_local_charset(0));
     if (data->local_charset == NULL) {
         ret = ISO_OUT_OF_MEM;
         goto fs_cleanup;

libisofs/libisofs.h

@@ -835,6 +835,36 @@ int iso_init();
  */
 void iso_finish();
 
+/**
+ * Override the reply of libc function nl_langinfo(CODESET) which may or may
+ * not give the name of the character set which is in effect for your
+ * environment. So this call can compensate for inconsistent terminal setups.
+ * Another use case is to choose UTF-8 as intermediate character set for a
+ * conversion from an exotic input character set to an exotic output set.
+ *
+ * @param name
+ *     Name of the character set to be assumed as "local" one.
+ * @param flag
+ *     Unused yet. Submit 0.
+ * @return
+ *     1 indicates success, <=0 failure
+ *
+ * @since 0.6.12
+ */
+int iso_set_local_charset(char *name, int flag);
+
+/**
+ * Obtain the local charset as currently assumed by libisofs.
+ * The result points to internal memory. It is volatile and must not be
+ * altered.
+ *
+ * @param flag
+ *     Unused yet. Submit 0.
+ *
+ * @since 0.6.12
+ */
+char *iso_get_local_charset(int flag);
+
 /**
  * Create a new image, empty.
  *

libisofs/util.c

@@ -40,6 +40,30 @@ int int_pow(int base, int power)
     return result;
 }
 
+/* This static variable can override the locale's charset by its getter
+   function which should be used whenever the local character set name
+   is to be inquired. I.e. instead of calling nl_langinfo(CODESET) directly.
+   If the variable is empty then it forwards nl_langinfo(CODESET).
+*/
+static char libisofs_local_charset[4096]= {""};
+
+/* API function */
+int iso_set_local_charset(char *name, int flag)
+{
+    if(strlen(name) >= sizeof(libisofs_local_charset))
+        return(0);
+    strcpy(libisofs_local_charset, name);
+    return 1;
+}
+
+/* API function */
+char *iso_get_local_charset(int flag)
+{
+   if(libisofs_local_charset[0])
+     return libisofs_local_charset;
+   return nl_langinfo(CODESET);
+}
+
 int strconv(const char *str, const char *icharset, const char *ocharset,
             char **output)
 {
@@ -1219,8 +1243,13 @@ char *ucs2str(const char *buf, size_t len)
     out = alloca(outbytes);
 
     /* convert to local charset */
+
+    /* ??? ts Nov 25 2008 :
+       Shouldn't this go to library initialization or even to app ?
+    */
     setlocale(LC_CTYPE, "");
-    conv = iconv_open(nl_langinfo(CODESET), "UCS-2BE");
+
+    conv = iconv_open(iso_get_local_charset(0), "UCS-2BE");
     if (conv == (iconv_t)(-1)) {
         return NULL;
     }