How do I grep for multiple words in a file?

How do I grep for multiple words in a file?

The basic grep syntax when searching multiple patterns in a file includes using the grep command followed by strings and the name of the file or its path. The patterns need to be enclosed using single quotes and separated by the pipe symbol. Use the backslash before pipe | for regular expressions.

How do I search for multiple text files in Linux?

How to use the grep tool

1. Make the search case-insensitive with the “-i” option:
2. Search recursively in all files in a given directory with the “-r” option:
3. Search whole words only with the “-w” option:
4. Print the line numbers in which the searched word was found with the “-n” option:
5. Search for multiple words syntax:

Can we use multiple grep in Linux?

Grep Multiple Patterns To search for multiple patterns, use the OR (alternation) operator. The alternation operator | (pipe) allows you to specify different possible matches that can be literal strings or expression sets. This operator has the lowest precedence of all regular expression operators.

What is grep in shell script?

The grep filter searches a file for a particular pattern of characters, and displays all lines that contain that pattern. The pattern that is searched in the file is referred to as the regular expression (grep stands for global search for regular expression and print out). Syntax: grep [options] pattern [files]

How do you grep recursively?

Recursive Search To recursively search for a pattern, invoke grep with the -r option (or –recursive ). When this option is used grep will search through all files in the specified directory, skipping the symlinks that are encountered recursively.

How do I combine two grep commands?

Two possibilities:

1. Group them: { grep ‘substring1’ file1.txt grep ‘substring2’ file2.txt } > outfile.txt.
2. Use the appending redirection operator >> for the second redirection: grep ‘substring1’ file1.txt > outfile.txt grep ‘substring2’ file2.txt >> outfile.txt.

How do I search for a string in Linux?

To search recursively, use the -r option with grep . As you can see, grep searched multiple directories and indicates where it found the string. You could also specify a directory in your command, but omitting it (as we did in this example) will instruct grep to search every directory in the current path.

How do you egrep multiple strings?

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.