Provide examples for most commands, enhance pyesc, remove superfluous printfesc

Makefile

@@ -7,6 +7,8 @@ TARGETS += printfesc
 TARGETS += xor 
 TARGETS += unhex
 TARGETS += pcat
+TARGETS += skip
+TARGETS += hex
 
 all: $(TARGETS)
 

README.md

@@ -42,15 +42,18 @@ Like the normal hd,
 but with unicode characters to represent all 256 octets,
 instead of using "." for unprintable characters.
 
+	$ printf "\0\x01\x02\x03\x30\x52\x9a" | hd
+	00000000  00 01 02 03 30 52 9a                              ┆·☺☻♥0RÜ┆
+	00000007
+
 
 ### unhex: unescape hex
 
 Reads ASCII hex codes on stdin,
 writes those octets to stdout.
 
-The following pipe is equivalent to "cat":
+	$ echo 68 65 6c 6c 6f 0a | unhex
-
+	hello
-    ./hd | cut -b 11-58 | ./unhex
 
 
 ### xor: xor mask octets
@@ -62,24 +65,27 @@ For a 16-value mask, the mask is applied to 16-octet chunks at a time.
 
 The "-x" option treats values as hex.
 
-The following pipe is equivalent to "cat":
+	$ printf 'hello' | xor 22; echo
-
+	~szzy
-	./xor 42 | ./xor -x 2A
+	$ printf 'hello' | xor 0x16; echo
+	~szzy
+	$ printf 'hello' | xor -x 16; echo
+	~szzy
+	$ printf 'bbbbbb' | xor 1 0; echo
+	cbcbcb
 
 
 ### skip: discard initial octets
 
 Throws away some initial octets from stdin,
 and sends the rest to stdout.
+
 You could use `dd` for the same purpose.
 
-This skip command:
+	$ echo abcdefgh | dd skip=5 bs=1 status=none
-
+	fgh
-	skip 5
+	$ echo abcdefgh | skip 5
-
+	fgh
-Is equivalent to this `dd` command:
-
-    dd skip=5 bs=1 status=none
 
 
 ### pcat: print text representation of pcap file
@@ -120,22 +126,19 @@ writing to output.
 
 ### hex: hex-encode input
 
-The opposite of `unhex`.
+The opposite of `unhex`:
+encoding all input into a single output line.
 
-The following is the equivalent of `cat`:
+	$ printf "hello\nworld\n" | hex
-
+	68 65 6c 6c 6f 0a 77 6f  72 6c 64 0a
-    hex | unhex
-
-
-### printfesc: printf escape input
-
-Reads octets,
-writes a string suitable for copy-paste into printf.
 
 
 ### pyesc: python escape input
 
 Escapes input octets for pasting into a python "print" statement.
+Also suitable for use as a C string,
+a Go string,
+and many other languages' string literals.
 
-
+	$ printf "hello\nworld\n" | pyesc
-
+	hello\nworld\n

hex.c

@@ -11,11 +11,16 @@ main(int argc, char *argv[])
 		if (EOF == c) {
 			break;
 		}
-		printf("%02x ", c);
+
-		if (7 == count % 8) {
+		if (count) {
+			putchar(' ');
+			if (0 == count % 8) {
 				putchar(' ');
 			}
 		}
+
+		printf("%02x", c);
+	}
 	putchar('\n');
 
 	return 0;

printfesc.c

@@ -1,40 +0,0 @@
-#include <stdio.h>
-#include <ctype.h>
-
-int
-main(int argc, char *argv[])
-{
-	printf("printf ");
-
-	while (!feof(stdin)) {
-		int c = getchar();
-
-		switch (c) {
-			case EOF:
-				break;
-			case '\n':
-				printf("\\n");
-				break;
-			case '\r':
-				printf("\\r");
-				break;
-			case '\t':
-				printf("\\t");
-				break;
-			case '"':
-				printf("\\\"");
-				break;
-			default:
-				if (isprint(c)) {
-					putchar(c);
-				} else {
-					printf("\\%03o", c);
-				}
-				break;
-		}
-	}
-
-	putchar('\n');
-
-	return 0;
-}

pyesc.c

@@ -8,7 +8,17 @@ main(int argc, char *argv[])
 
 		switch (c) {
 			case EOF:
+				putchar('\n');
 				return 0;
+			case 8:
+				printf("\\t");
+				break;
+			case 10:
+				printf("\\n");
+				break;
+			case 13:
+				printf("\\r");
+				break;
 			case 134:
 				printf("\\\\");
 				break;