![]() ![]() ‘-r’ option in grep command is used to search pattern recursively in folder and sub-folders. Linuxtechi:x:1000:1000:linuxtechi,:/home/linuxtechi:/bin/bash List all the lines of /etc/passwd that ends with “ bash” word. $ 7) Print all the lines that ends with specific wordīash shell treats dollar symbol ‘$’ as a special character which marks the ends of line or word. Let’s display the lines which starts with “backup” word in the file /etc/passwd, run $ grep ^backup /etc/passwdīackup:x:34:34:backup:/var/backups:/usr/sbin/nologin Using the option ‘-v’ in grep command, we can display the lines which don’t match the pattern $ grep -v 'nobody' /etc/passwdĦ) Print all lines that starts with specific patternīash shell treats caret symbol (^) as a special character which marks the beginning of line or a word. In below example, pattern is ‘nobody’ $ grep -n 'nobody' /etc/passwdġ8:nobody:x:65534:65534:nobody:/nonexistent:/usr/sbin/nologin Use ‘-n’ option in grep command to display line and its number which matches the pattern or word. $ 4) Display the line number with output lines $ grep -l 'root' /etc/fstab /etc/passwd /etc/mtab Let’s assume we want to list the files names which contains word ‘root’, to do so use ‘-l’ option in grep command followed by word (pattern) and files. $ sudo grep linuxtechi /etc/passwd /etc/shadow /etc/gshadowģ) Print file names that matches the pattern Run following to search ‘linuxtechi’ word in /etc/passwd, /etc/shadow and /etc/gshadow files. ![]() $ 2) Searching pattern in the multiple filesĪ word or a pattern can be searched in multiple files using grep command. Search a word “nobody” word in the file /etc/passwd file, $ grep nobody /etc/passwd When we run grep command followed by search string or pattern then it will print the matching line of a file. Q2.Without any further delay, let’s deep dive into grep command examples. What will be the output of the following command Practice Questions on use of grep in Linuxįor all these questions consider f1.txt (as defined above) as the input file For example, if you want to search for either the or and then: e: option is used to search for multiple patterns. Suppose you want to know the names of all files containing a given pattern, then -l option can be used. l: option will print the names of files that contain the pattern. To print names of all files containing the pattern ![]() v: option prints those lines which do not contain the specified pattern. To print the lines not containing the pattern Thus, it prints all lines containing the pattern in any case. i: options makes grep ignore case-sensitivity. c: option prints the count of lines containing the pattern rather than the lines themselves. To count the number of lines containing the pattern Thus, printing the line number along with the line becomes beneficial. In this case, just getting the line containing the pattern may not be sufficient because it will still require a considerable amount of effort to find the desired line in the file. It might be the case that the file in which you are searching contains thousands of lines. n: option prints the line numbers along with the line. To print line numbers of lines containing the pattern Options used with grep command in Linux 1. That’s why In in the fourth line of f1.txt was not the part of the output in the above example. The first line contains in as part of the word line and the second line has in as such. Grep displays the lines containing the pattern in. Grep prints the lines which contains the patternĬreate a file f1.txt which contains the following data: This is the first line For example, the as a pattern means all of these: the, then, there, 12 the34. For example, if you want to search for “help” within a file f1.txt, then you can use grep command. Grep command in Linux is used to search for patterns within a file i.e., it will help to your search for content within a file.
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