sed

7stud · 03-01-2007, 04:53 AM

I tried these commands, but they wouldn't work:

Code:

dialup-1:~/2testing/dir1 user1$ sed 1a"appended text" sedTest1
sed: 1: "1aappended text": command a expects \ followed by text

dialup-1:~/2testing/dir1 user1$ sed 1a\"appended text" sedTest1
> 
(I hit ctrl+C to get back to the prompt)

dialup-1:~/2testing/dir1 user1$ sed '1a\appended text' sedTest1
sed: 1: "1a\appended text": extra characters after \ at the end of a command

However, if I use a separate file, I can make it work:

Code:

dialup-1:~/2testing/dir1 user1$ sed -f edits.sedscr sedTest1

Quote:

edits.sedscr
-----------------
1a\
appended text

Is there a way to do it directly on the command line?

toreric · 03-01-2007, 06:09 AM

Both

$ sed 1a"appended text" test
original line 1
appended text
original line 2
original line 3

and

$ sed 1a'appended text' test|sed 1a'APPENDED TEXT'
original line 1
APPENDED TEXT
appended text
original line 2
original line 3

work for me (bash), but the best choice of delimiting character may vary with systems (a slash may be misinterpreted as catalog delimiter, etc.)

7stud · 03-01-2007, 02:10 PM

I'm using bash on mac os x 10.4.7 if that makes any difference.

From the man pages:

Code:

[1addr]a\
     text    Write text to standard output immediately before each attempt to
             read a line of input, whether by executing the ``N'' function or
             by beginning a new cycle.

I got this to work:

Code:

$ sed -e 'a\
>appended text' sedTest1

The man pages seem to indicate that the text has to be on a separate line. Interestingly, I got different behavior if I left out the -e switch:

Code:

$ sed 'a\
>appended text' sedTest1

In that case, the text was inserted at the beginning of a line starting with line 2:

Quote:

Original text
appended textOriginal text
appended textOriginal text
appended textdialup-1:~/2testing/dir1 user1$