Replace all UUID strings with new UUID strings

I have a text file contains some different UUID strings in it, I want to replace all the U开发者_运维知识库UID strings by new different UUID strings, how can I do that easily in Bash?

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Assuming the uuid format contains only hexadecimals with hyphens between them and these number of chars between each hypen: 8, 4, 4, 4, 12. I'm also assuming they are on their own line.

awk '
{
    if ($0 ~ /^[a-fA-F0-9]{8}-[A-Fa-f0-9]{4}-[A-Fa-f0-9]{4}-[A-Fa-f0-9]{4}-[A-Fa-f0-9]{12}$/)
    {
        system("uuidgen")
    }
    else
    {
        print $0
    }
}' file-with-uuids > new-file-with-uuids

# To override the old file with the new:
mv -f new-file-with-uuids file-with-uuids

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How about:

sed -i "s/$OLDUUID/$NEWUUID/g" file.txt 

can't tell from your description, if you have multiple (different) UUIDs to replace of these, you may need to chain such operations.

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Way late to this, but if anyone else is looking to replace all UUIDs in a file with new ones, this awk command should help:

awk '/[a-fA-F0-9]{8}-[A-Fa-f0-9]{4}-[A-Fa-f0-9]{4}-[A-Fa-f0-9]{4}-[A-Fa-f0-9]{12}/{"uuidgen" | getline uuid; close("uuidgen"); gsub(/[a-fA-F0-9]{8}-[A-Fa-f0-9]{4}-[A-Fa-f0-9]{4}-[A-Fa-f0-9]{4}-[A-Fa-f0-9]{12}/, uuid)};{print}' myfile > mynewfile

For each line that contains a uuid, it will generate a new uuid and then substitute the existing uuid for the newly generated one.