From ef3e5284bf078ef3cb0bd21c4883b341f8a2cb96 Mon Sep 17 00:00:00 2001
From: Elie De Brauwer <eliedebrauwer@gmail.com>
Date: Sat, 11 Feb 2012 14:58:50 +0100
Subject: Fix overflow in octal formatting in echo, add support for hexadecimal
 input, add tests for octal and hexadecimal formatting

---
 scripts/test/echo.test | 10 ++++++++++
 toys/echo.c            | 38 ++++++++++++++++++++++++++------------
 2 files changed, 36 insertions(+), 12 deletions(-)

diff --git a/scripts/test/echo.test b/scripts/test/echo.test
index 3eac172f..e269bf20 100755
--- a/scripts/test/echo.test
+++ b/scripts/test/echo.test
@@ -23,3 +23,13 @@ testing "echo --hello" "$CMD --hello" "--hello\n" "" ""
 testing "echo -e all" "$CMD -e '\a\b\c\f\n\r\t\v\\\0123'" \
 	"\a\b\c\f\n\r\t\v\\\0123\n" "" ""
 testing "echo -nex hello" "$CMD -nex hello" "-nex hello\n" "" ""
+
+# Octal formatting tests
+testing "echo -e octal values" \
+	"$CMD -ne '\01234 \0060 \060 \0130\0131\0132 \077\012'" \
+	"S4 0 0 XYZ ?\n" "" ""
+
+# Hexadecimal value tests
+testing "echo -e hexadecimal values" \
+	"$CMD -ne '\x534 \x30 \x58\x59\x5a \x3F\x0A'"\
+	"S4 0 XYZ ?\n" "" ""
diff --git a/toys/echo.c b/toys/echo.c
index 5feb9899..f7c423cf 100644
--- a/toys/echo.c
+++ b/toys/echo.c
@@ -17,17 +17,19 @@ config ECHO
 	  Write each argument to stdout, with one space between each, followed
 	  by a newline.
 
-	  -n	No trailing newline.
-	  -e	Process the following escape sequences:
-	  	\\	backslash
-	  	\a	alert (beep/flash)
-	  	\b	backspace
-	  	\c	Stop output here (avoids trailing newline)
-	  	\f	form feed
-	  	\n	newline
-	  	\r	carriage return
-	  	\t	horizontal tab
-	  	\v	vertical tab
+	  -n    No trailing newline.
+	  -e    Process the following escape sequences:
+	   \\     backslash
+	   \0NNN octal values (1 to 3 digits)
+	   \a    alert (beep/flash)
+	   \b    backspace
+	   \c    stop output here (avoids trailing newline)
+	   \f    form feed
+	   \n    newline
+	   \r    carriage return
+	   \t    horizontal tab
+	   \v    vertical tab
+	   \xHH  hexadecimal values (1 to 2 digits)
 */
 
 #include "toys.h"
@@ -60,10 +62,22 @@ void echo_main(void)
 						if (found) c = to[found-from];
 						else if (d == 'c') goto done;
 						else if (d == '0') {
+							int n = 0;
 							c = 0;
-							while (arg[j]>='0' && arg[j]<='7')
+							while (arg[j]>='0' && arg[j]<='7' && n++<3)
 								c = (c*8)+arg[j++]-'0';
 						}
+						else if (d == 'x') {
+							int n = 0;
+							c = 0;							
+							while (n++<2)
+								if (arg[j]>='0' && arg[j]<='9')
+									c = (c*16)+arg[j++]-'0';
+								else if (tolower(arg[j])>='a' && tolower(arg[j])<='f')
+									c = (c*16)+tolower(arg[j++])-'a'+10;
+								else
+									break;							
+						}
 					}
 				}
 				xputc(c);
-- 
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