1 files changed, 28 insertions, 0 deletions
diff --git a/hex2bin.c b/hex2bin.c
new file mode 100644
index 0000000..78efd60
--- /dev/null
+++ b/hex2bin.c
@@ -0,0 +1,28 @@
+#include <stdint.h>
+#include <stdio.h>
+#include <ctype.h>
+
+int main() {
+	char c;
+	int n = 0;
+	int count = 0;
+	int skipLine = 0;
+	while ((c = getchar()) != EOF) {
+		if (skipLine && c != '\n') continue;
+		if (isxdigit(c)) {
+			++count;
+			n <<= 4;
+			if (isdigit(c)) {
+				n |= c - '0';
+			} else {
+				n += 10 + tolower(c) - 'a';
+			}
+		}
+		if (count >= 2 || (count && !isxdigit(c))) {
+			putchar(n);
+			n = count = 0;
+		}
+		skipLine = c == '#';
+	}
+	return 0;
+}