'How to give a pattern for new line in grep?
How to give a pattern for new line in grep? New line at beginning, new line at end. Not the regular expression way. Something like \n.
Solution 1:[1]
try pcregrep instead of regular grep:
pcregrep -M "pattern1.*\n.*pattern2" filename
the -M option allows it to match across multiple lines, so you can search for newlines as \n.
Solution 2:[2]
Thanks to @jarno I know about the -z option and I found out that when using GNU grep with the -P option, matching against \n is possible. :)
Example:
grep -zoP 'foo\n\K.*'<<<$'foo\nbar'
Result:
bar
Example that involves matching everything including newlines:
.* will not match newlines. To match everything including newlines, use1(.|\n)*:
grep -zoP 'foo\n\K(.|\n)*'<<<$'foo\nbar\nqux'
Result:
bar
qux
1 Seen here: https://stackoverflow.com/a/33418344
Solution 3:[3]
You can use this way...
grep -P '^\s$' file
-Pis used for Perl regular expressions (an extension to POSIXgrep).\smatch the white space characters; if followed by*, it matches an empty line also.^matches the beginning of the line.$matches the end of the line.
Solution 4:[4]
As for the workaround (without using non-portable -P), you can temporary replace a new-line character with the different one and change it back, e.g.:
grep -o "_foo_" <(paste -sd_ file) | tr -d '_'
Basically it's looking for exact match _foo_ where _ means \n (so __ = \n\n). You don't have to translate it back by tr '_' '\n', as each pattern would be printed in the new line anyway, so removing _ is enough.
Solution 5:[5]
Sources
This article follows the attribution requirements of Stack Overflow and is licensed under CC BY-SA 3.0.
Source: Stack Overflow
| Solution | Source |
|---|---|
| Solution 1 | nullrevolution |
| Solution 2 | Robin A. Meade |
| Solution 3 | kenorb |
| Solution 4 | |
| Solution 5 | HHHartmann |