I created a text file and put some email addresses in it. Then I used grep to find them. Indeed it worked:
# pattern="^[a-zA-Z0-9]<a href="https://getridbug.com/cdn-cgi/l/email-protection" class="__cf_email__" data-cfemail="577c17">[email protected]</a>[a-zA-Z0-9]+.[a-z]{2,}"
# grep -E $pattern regexfile
but only as long I kept the -E option for an extended regular expression. How do I need to change the above regex in order to use grep without -E option?
Answers:
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Method 1
Be aware that matching email addresses is a LOT harder that what you have. See
an excerpt from the Mastering Regular Expressions book
However, to answer your question, for a basic regular expression, your quantifiers need to be one of *, + or {m,n} (with the backslashes)
pattern='^[a-zA-Z0-9]<a href="https://getridbug.com/cdn-cgi/l/email-protection" class="__cf_email__" data-cfemail="ddf69d">[email protected]</a>[a-zA-Z0-9]+.[a-z]{2,}'
grep "$pattern" regexfile
You need to quote the pattern variable
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