Add an unpatched version of xz, XZ Utils, to /trunk/deps/third_party

xz/debug/hex2bin.c

+///////////////////////////////////////////////////////////////////////////////
+//
+/// \file       hex2bin.c
+/// \brief      Converts hexadecimal input strings to binary
+//
+//  Author:     Lasse Collin
+//
+//  This file has been put into the public domain.
+//  You can do whatever you want with this file.
+//
+///////////////////////////////////////////////////////////////////////////////
+
+#include "sysdefs.h"
+#include <stdio.h>
+#include <ctype.h>
+
+
+static int
+getbin(int x)
+{
+        if (x >= '0' && x <= '9')
+                return x - '0';
+
+        if (x >= 'A' && x <= 'F')
+                return x - 'A' + 10;
+
+        return x - 'a' + 10;
+}
+
+
+int
+main(void)
+{
+        while (true) {
+                int byte = getchar();
+                if (byte == EOF)
+                        return 0;
+                if (!isxdigit(byte))
+                        continue;
+
+                const int digit = getchar();
+                if (digit == EOF || !isxdigit(digit)) {
+                        fprintf(stderr, "Invalid input\n");
+                        return 1;
+                }
+
+                byte = (getbin(byte) << 4) | getbin(digit);
+                if (putchar(byte) == EOF) {
+                        perror(NULL);
+                        return 1;
+                }
+        }
+}