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carillonator
Asked: 2010-09-23 08:20:54 +0800 CST

sed/awk: extract one number from string

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I have many lines like the following being returned from a bash command, with different sourceNodeIds of varying digit lengths:

<NodeAssociation sourceNodeId="33654" [...] sourceNodeEntity="Issue" />

I'd like to pipe it to sed or awk and just return the number nnnn from sourceNodeId="nnnn"

something like:

cat blah | sed 's/.+?sourceNodeId="\(\d+\)".+/\1/'

but this isn't working. I'm on a Mac if that makes any difference (I think the version of sed may be different). I know Perl regexes, but I think sed is expecting a different kind.

Thanks!!!

awk sed

2 Answers

  1. Best Answer

    sed doesn't know about \d and non-greedy matches. You don't need to use cat. This should work:

    sed 's/.*sourceNodeId="\([0-9]\+\)".*/\1/' file

    Some sed versions are picky about wanting a -e (it will work even if it's not required):

    sed -e 's/.*sourceNodeId="\([0-9]\+\)".*/\1/' file

    If your sed supports -r you can skip the escaping:

    sed -er 's/.*sourceNodeId="([0-9]+)".*/\1/' file
    • 3

  2. Also, works:

    cat blah | cut -f2 -d\"
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