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# 1  
Old 05-17-2011
Error Search and replace in text file


I have gigabytes of text files that I need to search for "&" and replace with "&amp". Is there a way to do this efficiently (like sed command)?

Hope you could help.

# 2  
Old 05-17-2011
give a try to
sed 's/&/&amp/g' infile

sed 's/[&]/&amp/g' infile

Last edited by ctsgnb; 05-18-2011 at 02:43 PM..
# 3  
Old 05-17-2011
Are there any other uses of the & in the file? If so, we'll need something a bit more elaborate. Also, you probably need:
sed 's/&/&/g' infile >outfile

Last edited by otheus; 05-17-2011 at 11:29 AM.. Reason: recolorize
# 4  
Old 05-17-2011
sed 's/&/&/g' infile >outfile

Ahem, ....

The "&" is a special character in sed regexps and means "the matched part completely here". For instance:

echo "huhu" | sed 's/hu/+&-/g'   # will result in "+hu-+hu-"

You will have to escape the "&":

sed 's/\&/\&/g' infile >outfile

I hope this helps.

# 5  
Old 05-17-2011

Yes, but if not escaped, it refers to the literal '&' previously matched so in fact it gives the same result Smilie

... but ok, i guess you pointed it out for education purpose...
This User Gave Thanks to ctsgnb For This Post:
# 6  
Old 05-18-2011
Originally Posted by bakunin
sed 's/\&/\&/g' infile >outfile

& is only special in the replacement text. It is an ordinary character in the regular expression. In the regular expression, the sequence \& yields undefined behavior. It will probably work as intended with most implementations, but it's not required to.

# 7  
Old 05-19-2011
I do.

vi ./file



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