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Comment by linkregister | Hacker News Reader

My biggest hardship with sed is having to figure out how to escape the operators within regular expressions on the command line. I think it's pretty reasonable to spend 15+ minutes on a complicated replacement regex.

Edit: It looks like I agree with you; `replace` only solves trivial problems that can easily be done with `sed`.

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Also sed can use other characters instead of / for separating fields, like using _ instead for / heavy stuff:

  sed -e 's_https://www\.example\.com/_/_g'

I think it's nicer than:

  sed -e 's/https:\/\/www\.example\.com\//\//g'

You can use single quotes to escape everything except single quotes from the shell. Then use backslashes to escape single quotes where needed.

If you haven't taken the time, I'd say it's well worth learning exactly how the shell escapes work. It's surprisingly simple and natural once you get used to it.

Thanks for the advice; I should block some time to fully grok shell escapes.

Even with single quotes, sed still requires escaping parentheses, + operators, and other operators that would otherwise be interpreted literally (but not all operators should be escaped). In the languages that I learned regexes this wasn't required.

There's a command line switch -E for sed that gives you what we think of as "normal" regex escaping.

You have saved me many hours of future command line hacking. Thanks!

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