simple sed -i problem

Question

simple sed -i problem

$ sed -i 's/testing123/localhost/g' testing123.txt
sed: 1: "testing123.txt": undefined label 'esting123.txt'

The -i switch appears to not work correctly in 10.6.1. From man sed : "If a zero-length extension is given, no backup will be saved". However currently if a zero-length extension is given sed fails. If an extension is given, then sed will work properly:

$ sed -i .backup 's/testing123/localhost/g' testing123.txt
$

uMBP-17 3Ghz, Mac OS X (10.6)

Posted on Sep 10, 2009 10:24 PM

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Answer 1

Sep 11, 2009 5:23 AM in response to another_apple_customer

Technically you're not giving a zero-length extension. Whatever comes after the -i is the extension. Sed fails because this interpretation mangles your command. I'm not sure how you would specify a zero-length extension given that something will allows follow the -i. Maybe someone more versed in sed can chime in. I would just make sure there is always an extension.

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Answer 2

BobHarris

Level 9

56,885 points

Sep 11, 2009 5:40 AM in response to another_apple_customer


sed -i '' 's/testing123/localhost/g' testing123.txt

-i expects an argument, so it is going to take the next token from the command line.

If you want a zero length extension, then provide either a pair of single quotes or a pair of double quotes with nothing inside and that will be a zero-length extension that -i can understand.

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