Sage-Tips

How do I use grep to search for multiple patterns?

How do I grep for multiple patterns?

1. Use single quotes in the pattern: grep ‘pattern*’ file1 file2.
2. Next use extended regular expressions: egrep ‘pattern1|pattern2’ *. py.
3. Finally, try on older Unix shells/oses: grep -e pattern1 -e pattern2 *. pl.
4. Another option to grep two strings: grep ‘word1\|word2’ input.

What command will search for patterns inside of text files?

The grep command allows you to search for a pattern inside of files. If a match is found, grep prints the lines containing the specified pattern.

Can grep command be used for searching a pattern in more than one file?

grep command can be used for searching a pattern in more than one file. Explanation: We’ve to quote the pattern in double quotes when it contains multiple words or special characters else they will be interpreted in some other way by the shell.

How do I grep a directory pattern?

If you are in the directory that you want to do the search in, you have to do the following: grep -nr string . It is important to include the ‘. ‘ character, as this tells grep to search THIS directory.

How do I grep inside a file?

The grep command searches through the file, looking for matches to the pattern specified. To use it type grep , then the pattern we’re searching for and finally the name of the file (or files) we’re searching in. The output is the three lines in the file that contain the letters ‘not’.

How do I use grep to search all files in a directory?

To search all files in the current directory, use an asterisk instead of a filename at the end of a grep command. The output shows the name of the file with nix and returns the entire line.

Is grep faster than egrep?

Example: Note: The egrep command used mainly due to the fact that it is faster than the grep command. The egrep command treats the meta-characters as they are and do not require to be escaped as is the case with grep.

What does egrep stand for?

Global regular expression print
grep/Stands for

How do I Grep a file with multiple patterns?

Using sed command: GREP AND: Match Multiple Patterns. It is also often required to grep a file for multiple patterns – when it is needed to find all the lines in a file, that contain not one, but several patterns. Note, that you can both find the lines in a file that match multiple patterns in the exact order or in the any order.

How do I grep multiple files in Linux?

Search Recursively for Multiple Patterns in a File The grep command searches only in the current directory when you use the asterisk wildcard. To include all subdirectories when searching for multiple patterns, add the -R operator to grep: grep -R ‘warning|error’ /var/log/*.log

How do I search for multiple patterns in a file?

Search Recursively for Multiple Patterns in a File. The grep command searches only in the current directory when you use the asterisk wildcard. To include all subdirectories when searching for multiple patterns, add the -R operator to grep: grep -R ‘warning\\|error’ /var/log/*.log

How to search all files in the current directory using grep?

To search all files in the current directory, use an asterisk instead of a filename at the end of a grep command. In this example, we use nix as a search criterion: