Regex to match not start of line

I have the following XML开发者_如何学Go tag

<list message="2 < 3">

I want to replace the < in the text with <

Need a regex to match < if it doesn't appear at the start of line.

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Most likely you can do this using lookbehind:

/(?<!^)</

see: http://www.regular-expressions.info/lookaround.html

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[^<]+ = one or more characters that are not <

< = the < you're looking for

replace:

([^<]+)<

with:

$1<

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The dot '.' means "any value"

.<

Anyway, I suppose you don't want whitespaces, either. If so, then

\S\s*<

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This would give you "<" after the first instance:

[^<]<

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Try this:

(?<="[^"]*)<(?=[^"]*")

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@duncan's method works fine if you just want to replacing, but it doesn't match the <. and all the lookbehind wont work if you a using javascript. because javascript doesn't support lookbehind, unless you turn on the --harmony flag in nodejs or experimental javascript features in chrome. But lookahead will work here, which is: /(?!^)</ will match the < which is not at the begining of a line. and the replacing will be: '<list message="2 < 3">'.replace(/(?!^)</, '&lt;')