First phase of porting. pterm now compiles and runs under Linux+gtk.

The current pty.c backend is temporarily a loopback device for
terminal emulator testing, the display handling is only just enough
to show that terminal.c is functioning, the keyboard handling is
laughable, and most features are absent. Next step: bring output and
input up to a plausibly working state, and put a real pty on the
back to create a vaguely usable prototype. Oh, and a scrollbar would
be nice too.
In _theory_ the Windows builds should still work fine after this...

[originally from svn r2010]

unix/uxucs.c

@@ -0,0 +1,114 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <ctype.h>
+
+#include <time.h>
+#include "putty.h"
+#include "misc.h"
+
+/*
+ * Unix Unicode-handling routines.
+ * 
+ * FIXME: currently trivial stub versions assuming all codepages
+ * are ISO8859-1.
+ */
+
+void lpage_send(int codepage, char *buf, int len, int interactive)
+{
+    ldisc_send(buf, len, interactive);
+}
+
+void luni_send(wchar_t * widebuf, int len, int interactive)
+{
+    static char *linebuffer = 0;
+    static int linesize = 0;
+    int ratio = (in_utf)?6:1;
+    int i;
+    char *p;
+
+    if (len * ratio > linesize) {
+	sfree(linebuffer);
+	linebuffer = smalloc(len * ratio * 2 * sizeof(wchar_t));
+	linesize = len * ratio * 2;
+    }
+
+    if (in_utf) {
+	/* UTF is a simple algorithm */
+	for (p = linebuffer, i = 0; i < len; i++) {
+	    wchar_t ch = widebuf[i];
+
+	    if ((ch&0xF800) == 0xD800) ch = '.';
+
+	    if (ch < 0x80) {
+		*p++ = (char) (ch);
+	    } else if (ch < 0x800) {
+		*p++ = (0xC0 | (ch >> 6));
+		*p++ = (0x80 | (ch & 0x3F));
+	    } else if (ch < 0x10000) {
+		*p++ = (0xE0 | (ch >> 12));
+		*p++ = (0x80 | ((ch >> 6) & 0x3F));
+		*p++ = (0x80 | (ch & 0x3F));
+	    } else if (ch < 0x200000) {
+		*p++ = (0xF0 | (ch >> 18));
+		*p++ = (0x80 | ((ch >> 12) & 0x3F));
+		*p++ = (0x80 | ((ch >> 6) & 0x3F));
+		*p++ = (0x80 | (ch & 0x3F));
+	    } else if (ch < 0x4000000) {
+		*p++ = (0xF8 | (ch >> 24));
+		*p++ = (0x80 | ((ch >> 18) & 0x3F));
+		*p++ = (0x80 | ((ch >> 12) & 0x3F));
+		*p++ = (0x80 | ((ch >> 6) & 0x3F));
+		*p++ = (0x80 | (ch & 0x3F));
+	    } else {
+		*p++ = (0xFC | (ch >> 30));
+		*p++ = (0x80 | ((ch >> 24) & 0x3F));
+		*p++ = (0x80 | ((ch >> 18) & 0x3F));
+		*p++ = (0x80 | ((ch >> 12) & 0x3F));
+		*p++ = (0x80 | ((ch >> 6) & 0x3F));
+		*p++ = (0x80 | (ch & 0x3F));
+	    }
+	}
+    } else {
+	for (p = linebuffer, i = 0; i < len; i++) {
+	    wchar_t ch = widebuf[i];
+	    if (ch < 0x100)
+		*p++ = (char) ch;
+	    else
+		*p++ = '.';
+	}
+    }
+    if (p > linebuffer)
+	ldisc_send(linebuffer, p - linebuffer, interactive);
+}
+
+int is_dbcs_leadbyte(int codepage, char byte)
+{
+    return 0;			       /* we don't do DBCS */
+}
+
+int mb_to_wc(int codepage, int flags, char *mbstr, int mblen,
+	     wchar_t *wcstr, int wclen)
+{
+    int ret = 0;
+    while (mblen > 0 && wclen > 0) {
+	*wcstr++ = (unsigned char) *mbstr++;
+	ret++;
+    }
+    return ret;			       /* FIXME: check error codes! */
+}
+
+void init_ucs(void)
+{
+    int i;
+    /* Find the line control characters. FIXME: this is not right. */
+    for (i = 0; i < 256; i++)
+	if (i < ' ' || (i >= 0x7F && i < 0xA0))
+	    unitab_ctrl[i] = i;
+	else
+	    unitab_ctrl[i] = 0xFF;
+
+    for (i = 0; i < 256; i++) {
+	unitab_line[i] = unitab_scoacs[i] = i;
+	unitab_xterm[i] = i & 0x1F;
+    }
+}