Initial import

tool/decode/xor.c

@@ -0,0 +1,38 @@
+/*─────────────────────────────────────────────────────────────────╗
+│ To the extent possible under law, Justine Tunney has waived      │
+│ all copyright and related or neighboring rights to this file,    │
+│ as it is written in the following disclaimers:                   │
+│   • http://unlicense.org/                                        │
+│   • http://creativecommons.org/publicdomain/zero/1.0/            │
+╚─────────────────────────────────────────────────────────────────*/
+#include "libc/runtime/gc.h"
+#include "libc/stdio/stdio.h"
+#include "libc/str/str.h"
+#include "libc/x/x.h"
+
+/**
+ * @fileoverview Hex to binary converter program.
+ * Non-hex bytes are ignored. If you've got imposter syndrome you could
+ * call this a compiler and start coding in hex.
+ */
+
+int main(int argc, char *argv[]) {
+  size_t i, j, l;
+  uint8_t *buf;
+  if (argc == 1) return 1;
+  buf = gc(xmalloc((l = strlen(argv[1]) / 2)));
+  for (j = 0; j < l; ++j) {
+    buf[j] = 0;
+  }
+  for (i = 1; i < argc; ++i) {
+    for (j = 0; j < l; ++j) {
+      buf[j] ^= hextoint(argv[i][j + 0]) << 4 | hextoint(argv[i][j + 1]);
+    }
+  }
+  for (j = 0; j < l; ++j) {
+    putchar("0123456789abcdef"[(buf[j] >> 4) & 0xf]);
+    putchar("0123456789abcdef"[(buf[j] >> 0) & 0xf]);
+  }
+  putchar('\n');
+  return 0;
+}