Add undec and unoct

Makefile

@@ -8,6 +8,8 @@ TARGETS += hd
 TARGETS += pyesc 
 TARGETS += xor 
 TARGETS += unhex
+TARGETS += undec
+TARGETS += unoct
 TARGETS += pcat
 TARGETS += slice
 TARGETS += hex

README.md

@@ -105,12 +105,27 @@ You can disable this with `-v`
 
 ## unhex: unescape hex
 
-Reads ASCII hex codes on stdin,
+Reads octet hex codes on stdin,
 writes those octets to stdout.
 
     $ echo 68 65 6c 6c 6f 0a | unhex
     hello
 
+## undec: unescape decimal
+
+Reads octet decimal codes on stdin,
+writes those octets to stdout.
+
+    $ echo 104 101 108 108 111 10 | undec
+    hello
+
+## unoct: unescape octal
+
+Reads octet octal codes on stdin,
+writes those octets to stdout.
+
+    $ echo 150 145 154 154 157 012 | unoct 
+    hello
 
 ## xor: xor octets
 

undec.c

@@ -0,0 +1,48 @@
+/*
+ * Hex Decoder -- 2012 Zephyr <zephyr@dirtbags.net> This file is in the public domain.  I make no promises about the functionality 
+ * of this program. 
+ */
+
+#include <stdio.h>
+
+int
+main(int argc, char *argv[])
+{
+	unsigned char acc = 0;
+	unsigned char digit = 0;
+	unsigned long int count = 0;
+
+	while (1) {
+		int c = getchar();
+
+		count += 1;
+
+		switch (c) {
+			case EOF:
+				return 0;
+			case ' ':
+			case '\r':
+			case '\n':
+			case '\t':
+				digit += 3;
+				break;
+			case '0' ... '9':
+				acc = (acc * 10) + c - '0';
+				digit += 1;
+				break;
+			default:
+				if (digit != 0) {
+					fprintf(stderr, "Warning: non-numeric character mid-octet at offset %lu\n", count);
+				}
+				break;
+		}
+
+		if (digit > 3) {
+			putchar(acc);
+			acc = 0;
+			digit = 0;
+		}
+	}
+
+	return 0;
+}

unoct.c

@@ -0,0 +1,48 @@
+/*
+ * Octal Decoder -- 2012 Zephyr <zephyr@dirtbags.net> This file is in the public domain.  I make no promises about the functionality 
+ * of this program. 
+ */
+
+#include <stdio.h>
+
+int
+main(int argc, char *argv[])
+{
+	unsigned char acc = 0;
+	unsigned char digit = 0;
+	unsigned long int count = 0;
+
+	while (1) {
+		int c = getchar();
+
+		count += 1;
+
+		switch (c) {
+			case EOF:
+				return 0;
+			case ' ':
+			case '\r':
+			case '\n':
+			case '\t':
+				digit += 3;
+				break;
+			case '0' ... '7':
+				acc = (acc * 8) + c - '0';
+				digit += 1;
+				break;
+			default:
+				if (digit != 0) {
+					fprintf(stderr, "Warning: non-numeric character mid-octet at offset %lu\n", count);
+				}
+				break;
+		}
+
+		if (digit > 3) {
+			putchar(acc);
+			acc = 0;
+			digit = 0;
+		}
+	}
+
+	return 0;
+}