From owner-freebsd-questions  Fri May 31  5:13:53 2002
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Date: Fri, 31 May 2002 14:13:52 +0200
From: Miguel Mendez <flynn@energyhq.homeip.net>
To: j mckitrick <jcm@FreeBSD-uk.eu.org>
Cc: freebsd-questions@freebsd.org
Subject: Re: Why does 'sed' delete my input file?
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In-Reply-To: <20020531130029.B28925@dogma.freebsd-uk.eu.org>; from jcm@FreeBSD-uk.eu.org on Fri, May 31, 2002 at 01:00:29PM +0100
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On Fri, May 31, 2002 at 01:00:29PM +0100, j mckitrick wrote:

Hi,

> If I want to replace all occurrences of 'foo' in a file, this is what I
> tried:
>=20
> sed s/foo/bar/g file1 > file1
>=20
> But this deletes (overwrites?) the contents of the file.  What did I do
> wrong?

It's not sed that does that. Note that you are redirecting the output
with '>', so the shell truncates file1.

However, there are other ways to do that. sed will soon have a -i option
soon, but in the meantime you could just:

sed -e 's/foo/bar/g' file1 > file1.tmp && mv file1.tmp file1

or

perl -pi -e 's/foo/bar/g' file1

Cheers,
--=20
        Miguel Mendez - flynn@energyhq.homeip.net
        GPG Public Key :: http://energyhq.homeip.net/files/pubkey.txt
        EnergyHQ :: http://www.energyhq.tk
        FreeBSD - The power to serve!

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