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echo backspace

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# 1  
Old 12-11-2010
echo backspace
Hello Forum:

I am trying to find a meaning to this echo escape character:
Code:
echo -e "\b"

Can someone tell me or give me examples of the effect that this has when used. I know that \b is the backspace, but I cannot visualise it use like any other escape such as:
Code:
echo -e "\n"

Thanks.
--Willie
Last edited by Scott; 12-12-2010 at 04:39 AM..
# 2  
Old 12-11-2010
Code:
$ echo -e '12345\b6'
12346

# 3  
Old 12-11-2010
Thanks Scrutinizer.

Any others?
# 4  
Old 12-11-2010
Like how carriage returns return the carriage, like how new lines cause a new line, back space moves the cursor back one space. It does not erase, just moves the cursor. This behavior happens wholly within the terminal, backspace is still just another character as far as any programs are concerned:

Code:
$ echo -e '12345\b6' | hexdump -C
00000000  31 32 33 34 35 08 36 0a                           |12345.6.|
00000008
$

That's really all there is to it.
Last edited by Corona688; 12-11-2010 at 10:37 PM..
# 5  
Old 12-11-2010
Further to Corona688.

The settings in "stty -a" matter.

On a conventional DEC vtxx terminal (or emulator) this unix command will turn the backspace key into a destructive erase key.
Code:
stty erase "^H"

# 6  
Old 12-11-2010
Thanks methyl.

I believe this might be one of the most abstract escape characters, in my opinion.

--Willie

---------- Post updated at 09:53 PM ---------- Previous update was at 09:52 PM ----------

Thanks Corona688.

Thanks for your time guys.


--Willie
# 7  
Old 12-11-2010
It's all abstract. What makes moving back more abstract than moving forward, down, or to the beginning of the line?
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