[lcd4linux @ 2006-09-15 19:00:50 by entropy]

iconv charset converter plugin

git-svn-id: https://ssl.bulix.org/svn/lcd4linux/trunk@717 3ae390bd-cb1e-0410-b409-cd5a39f66f1f

1 files changed, 146 insertions, 0 deletions

diff --git a/plugin_iconv.c b/plugin_iconv.c
new file mode 100644
index 0000000..b21d70b
--- /dev/null
+++ b/plugin_iconv.c
@@ -0,0 +1,146 @@
+/* $Id: plugin_iconv.c,v 1.1 2006/09/15 19:00:50 entropy Exp $
+ *
+ * iconv charset conversion plugin
+ *
+ * Copyright (C) 2006 Ernst Bachmann <e.bachmann@xebec.de>
+ * Copyright (C) 2006 The LCD4Linux Team <lcd4linux-devel@users.sourceforge.net>
+ *
+ * This file is part of LCD4Linux.
+ *
+ * LCD4Linux is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2, or (at your option)
+ * any later version.
+ *
+ * LCD4Linux is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ *
+ *
+ * $Log: plugin_iconv.c,v $
+ * Revision 1.1  2006/09/15 19:00:50  entropy
+ * iconv charset converter plugin
+ *
+ *
+ */
+
+/* 
+ * exported functions:
+ *
+ * int plugin_init_iconv (void)
+ * int plugin_exit_iconv (void)
+ *
+ */
+
+
+#include "config.h"
+
+#include <stdlib.h>
+#include <string.h>
+#include <ctype.h>
+#include <iconv.h>
+#include <errno.h>
+
+/* these should always be included */
+#include "debug.h"
+#include "plugin.h"
+
+#ifdef WITH_DMALLOC
+#include <dmalloc.h>
+#endif
+
+
+
+/* iconv function, convert charsets */
+/* valid "to" and "from" charsets can be listed by running "iconv -list" from a shell */
+/* utf16 & utf32 encodings won't work, as they contain null bytes, confusing strlen */ 
+static void my_iconv(RESULT * result, RESULT * charset_from, RESULT * charset_to, RESULT * arg)
+{
+    char *source;
+    size_t source_left;
+    char *dest;
+    char *dest_pos;
+    size_t dest_left;
+    iconv_t cd;
+
+    source = R2S(arg);
+    source_left = strlen(source);
+
+    /* use twice the memory needed in best case, but save lots of reallocs in worst case */
+    /* increase to 4 if most conversions are to utf32 (quite unlikely) */
+    /* also alloc a "safety byte" so we can always zero-terminate the string. */
+
+    dest_left = 2 * source_left;
+    dest = malloc(dest_left + 1);
+    dest_pos = dest;
+
+    cd = iconv_open(R2S(charset_to), R2S(charset_from));
+    if (cd != (iconv_t) (-1)) {
+
+	do {
+	    debug("plugin_iconv: calling iconv with %ld,[%s]/%ld,%ld", cd, source, source_left, dest_left);
+	    if (iconv(cd, &source, &source_left, &dest_pos, &dest_left) == (size_t) (-1)) {
+		switch (errno) {
+		case EILSEQ:
+		    /* illegal bytes in input sequence */
+		    /* try to fix by skipping a byte */
+		    info("plugin_iconv: illegal character in input string: %c", *source);
+		    source_left--;
+		    source++;
+		    break;
+		case EINVAL:
+		    /* input string ends during a multibyte sequence */
+		    /* try to fix by simply ignoring */
+		    info("plugin_iconv: illegal character at end of input");
+		    source_left = 0;
+		    break;
+		case E2BIG:
+		    /* not enough bytes in outbuf. */
+		    /* TODO: Realloc output buffer, probably doubling its size? */
+		    /* for now, just bail out. For lcd4linux 99% of all conversions will go to ascii or latin1 anyways */
+		    error
+			("plugin_iconv: out of memory in destination buffer. Seems like Ernst was too lazy, complain to him!");
+		    source_left = 0;
+		    break;
+		default:
+		    error("plugin_iconv: strange errno state (%d) occured", errno);
+		    source_left = 0;
+		}
+	    }
+	} while (source_left > 0);	/* don't check for == 0, could be negative in EILSEQ case */
+
+	/* terminate the string, we're sure to have that byte left, see above */
+	*dest_pos = 0;
+	dest_pos++;
+
+	iconv_close(cd);
+    } else {
+	error("plugin_iconv: could not open conversion descriptor. Check if your charsets are supported!");
+	/* guaranteed to fit. */
+	strcpy(dest, source);
+    }
+
+    SetResult(&result, R_STRING, dest);
+
+    free(dest);
+}
+
+
+/* plugin initialization */
+int plugin_init_iconv(void)
+{
+
+    AddFunction("iconv", 3, my_iconv);
+
+    return 0;
+}
+
+void plugin_exit_iconv(void)
+{
+    /* nothing to clean */
+}