Table of Contents
How do you grep either of two strings?
How do I grep for multiple patterns?
- Use single quotes in the pattern: grep ‘pattern*’ file1 file2.
- Next use extended regular expressions: egrep ‘pattern1|pattern2’ *. py.
- Finally, try on older Unix shells/oses: grep -e pattern1 -e pattern2 *. pl.
- Another option to grep two strings: grep ‘word1\|word2’ input.
How do you grep for not matching?
Exclude Words and Patterns To display only the lines that do not match a search pattern, use the -v ( or –invert-match ) option. The -w option tells grep to return only those lines where the specified string is a whole word (enclosed by non-word characters). By default, grep is case-sensitive.
How do you grep multiple lines after a match?
For BSD or GNU grep you can use -B num to set how many lines before the match and -A num for the number of lines after the match. If you want the same number of lines before and after you can use -C num . This will show 3 lines before and 3 lines after.
Which option is used with grep to print all lines that do not match pattern?
Inverting the pattern match : You can display the lines that are not matched with the specified search sting pattern using the -v option.
How do I exclude multiple words from grep?
Specify Multiple Patterns. The -e flag allows us to specify multiple patterns through repeated use. We can exclude various patterns using the -v flag and repetition of the -e flag: $ grep -ivw -e ‘the’ -e ‘every’ /tmp/baeldung-grep Time for some thrillin’ heroics.
How do you grep few lines before and after?
To also show you the lines before your matches, you can add -B to your grep. The -B 4 tells grep to also show the 4 lines before the match. Alternatively, to show the log lines that match after the keyword, use the -A parameter. In this example, it will tell grep to also show the 2 lines after the match.
How do I print 5 lines after grep?
You can use grep with -A n option to print N lines after matching lines. Using -B n option you can print N lines before matching lines. Using -C n option you can print N lines before and after matching lines.
How do you count lines with grep?
Using grep -c alone will count the number of lines that contain the matching word instead of the number of total matches. The -o option is what tells grep to output each match in a unique line and then wc -l tells wc to count the number of lines. This is how the total number of matching words is deduced.
How do you grep a new line character?
the -M option allows it to match across multiple lines, so you can search for newlines as \n . grep patterns are matched against individual lines so there is no way for a pattern to match a newline found in the input. At least GNU grep has -z option that makes grep break lines by null character.
How to grep for two words on the same line in Linux?
To grep for 2 words existing on the same line, simply do: grep “word1” FILE | grep “word2” grep “word1” FILEwill print all lines that have word1 in them from FILE, and then grep “word2″will print the lines that have word2 in them. Hence, if you combine these using a pipe, it will show lines containing both word1 and word2.
How do I grep all non matching lines in a string?
The -v option tells grep to keep non-matching lines and remove matching lines, instead of the opposite. This gives you half the results you wanted. By adding the symmetric search, you get all the lines containing exactly one of the words. Alternatively, you can start from the lines containing either word, and remove the lines containing both words.
How to use grep to search for more than two words?
To search for more than two words, keep adding them in the same manner. For example, to search for three words, add the desired string of characters followed by a backslash and pipe: Let’s see how the above grep command looks when using grep -E, egrep, and grep -e: We will use grep in further examples, but you can use whichever syntax you prefer.
How do I grep multiple patterns in Git?
Here is the syntax using git grep combining multiple patterns using Boolean expressions: git grep -e pattern1 –and -e pattern2 –and -e pattern3 The above command will print lines matching all the patterns at once. If the files aren’t under version control, add –no-index param.