Path: utzoo!utgpu!watserv1!watmath!iuvax!mailrus!uunet!virtech!cpcahil
From: cpcahil@virtech.uucp (Conor P. Cahill)
Newsgroups: comp.unix.questions
Subject: Re: Another sed question.
Message-ID: <1989Dec2.134348.22524@virtech.uucp>
Date: 2 Dec 89 13:43:48 GMT
References: <37091@ames.arc.nasa.gov>
Organization: Virtual Technologies Inc.
Lines: 27

In article <37091@ames.arc.nasa.gov>, gahooten@orion.arc.nasa.gov (Gregory A. Hooten) writes:
> #!/bin/sed d1

> What it did was to delete the line starting with the # sign and display all
> of the text that was in the file.  

> My questions are, why do it this way instead of using echo?

Because the programmer wanted to do it that way.  Lots of echos would have
been ugly, but a cat with here documents would have been just as clear and
probably as efficient.

> Why is the # line considered line 1, when it was used
> to start the command in the first space, it seems to me that the line would 
> have already been sent to the terminal to start the sed, and so would not
> be deleted?

Because nothing in the file is "sent to the terminal".  The kernel passes the
entire file to said program.



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| Conor P. Cahill     uunet!virtech!cpcahil      	703-430-9247	!
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