On 12/18/12 00:20, Stuart Henderson wrote:
On 2012/12/17 18:26, Andres Perera wrote:
On Mon, Dec 17, 2012 at 6:13 PM, Stuart Henderson <s...@spacehopper.org> wrote:
On 2012-12-17, sven falempin <sven.falem...@gmail.com> wrote:
Hello misc readers,
First, openBSD threads are awesome for debugging.
The trivial topic,
echo -ne "\x00" | nc XXXX port
send a null byte with a GNU echo.
Echo in openbsd does not have -e (and does not warn whan i try it ..)
Noob question:
How to send a null byte over netcat ? am i forced to use perl ?
you can use octal with echo(1) or printf(1).
echo(1) is BSD echo (no backslash sequences)
ksh echo is XSI + BSD
ah, right.
$ echo -n '\000' | hexdump -C
00000000 00 |.|
00000001
$ env echo -n '\000' | hexdump -C
00000000 5c 30 30 30 |\000|
00000004
in which case printf is probably a better idea.
For scripting, echo is one of the commands I tend to avoid unless I know
the data is "safe", because of it's horrific argument parsing.
I've yet to find a way to echo a single '-n' using the sh/ksh builtin.
When printing unknown data, I usually end up using 'print -r -- "$var"'
(or 'printf "%s" "$var"' if I care about portability).
/Alexander
