Path: utzoo!utgpu!jarvis.csri.toronto.edu!rutgers!apple!bloom-beacon!athena.mit.edu!jik
From: jik@athena.mit.edu (Jonathan I. Kamens)
Newsgroups: comp.unix.questions
Subject: Re:  does vi have a search/deletion macro???
Message-ID: <14154@bloom-beacon.MIT.EDU>
Date: 8 Sep 89 18:50:25 GMT
References: <20802@adm.BRL.MIL> <5285@ucdavis.ucdavis.edu>
Sender: daemon@bloom-beacon.MIT.EDU
Reply-To: jik@athena.mit.edu (Jonathan I. Kamens)
Organization: Massachusetts Institute of Technology
Lines: 66

In article <5285@ucdavis.ucdavis.edu> lee@iris.ucdavis.EDU (Peng Lee) writes:
>I have a similar question:  How do you delete a empty line using "sed"
>or "ed" ?  I have try the 'sed -e "/^$/d" filename ', but it doesn't work.
>
>-Thanx
>Peng (lee@iris.ucdavis.edu)

  If the lines are really blank, that will work.  However, they will
often contain tabs or spaces in them.  Therefore, what you should use
is "sed -e '/^[ ^I]*$/d' filename" (the ^I is a real tab character).
Watch this:

Script started on Fri Sep  8 14:44:19 1989
vulcan% cat test
This is a test file.
There is a blank line here:

Here's a line with a space on it:
 
And here's one with a tab on it:
        
And here's one with a space and a tab:
        
And this is the end of the file.
vulcan% sed '/^$/d' test
This is a test file.
There is a blank line here:
Here's a line with a space on it:
 
And here's one with a tab on it:
        
And here's one with a space and a tab:
        
And this is the end of the file.
vulcan% sed '/^[ ]*$/d' test
This is a test file.
There is a blank line here:
Here's a line with a space on it:
And here's one with a tab on it:
        
And here's one with a space and a tab:
        
And this is the end of the file.
vulcan% sed '/^[^I]*$/d' test
This is a test file.
There is a blank line here:
Here's a line with a space on it:
 
And here's one with a tab on it:
And here's one with a space and a tab:
        
And this is the end of the file.
vulcan% sed '/^[ ^I]*$d/' test
This is a test file.
There is a blank line here:
Here's a line with a space on it:
And here's one with a tab on it:
And here's one with a space and a tab:
And this is the end of the file.
vulcan% exit
script done on Fri Sep  8 14:45:24 1989

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