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# 1  
Old 09-25-2010
edit command
Code:
printf '3d\nw\nq\n' | ed -s file

please explain the above command what the (ed -s file) will do by getting the first input.
Last edited by vbe; 09-30-2010 at 05:11 AM..
# 2  
Old 09-25-2010
Quote:
Originally Posted by thelakbe
printf '3d\nw\nq\n' | ed -s file

please explain the above command what the (ed -s file) will do by getting the first input.
The printf command prints three "ed" commands as shown below:

Code:
$ 
$ printf '3d\nw\nq\n'
3d
w
q
$ 
$

"3d" means delete line number 3.
"w" means write to file.
"q" means quit "ed" editor.

These commands are piped to "ed", so it will execute them on the file "file" silently (due to "-s" flag).

A simple test is as follows -

Code:
$ 
$ 
$ cat -n f15
     1    This is line 1
     2    This is line 2
     3    This is line 3
     4    This is line 4
     5    This is line 5
     6    This is line 6
     7    This is line 7
$ 
$ 
$ printf '3d\nw\nq\n' | ed -s f15
$ 
$ cat -n f15
     1    This is line 1
     2    This is line 2
     3    This is line 4
     4    This is line 5
     5    This is line 6
     6    This is line 7
$ 
$

tyler_durden
This User Gave Thanks to durden_tyler For This Post:
thelakbe
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