The uniq command can count and print the number of repeated lines. Just like duplicate lines, we can filter unique lines (non-duplicate lines) as well and can also ignore case sensitivity. We can skip fields and characters before comparing duplicate lines and also consider characters for filtering lines.
Why uniq is used in Linux?
The uniq command in Linux is a command line utility that reports or filters out the repeated lines in a file. In simple words, uniq is the tool that helps to detect the adjacent duplicate lines and also deletes the duplicate lines.
What does uniq do in Unix?
uniq is a utility command on Unix, Plan 9, Inferno, and Unix-like operating systems which, when fed a text file or STDIN, outputs the text with adjacent identical lines collapsed to one, unique line of text.
What is uniq in bash?
uniq command is used to detect the adjacent lines from a file and write the content of the file by filtering the duplicate values or write only the duplicate lines into another file. …
Do you need to sort before uniq?
Checking the man page for uniq: Repeated lines in the input will not be detected if they are not adjacent, so it may be necessary to sort the files first. Alternatively, taking the man page suggestion, sorting the list before calling uniq will remove all of the duplicates.
Who WC Linux?
wc stands for word count. As the name implies, it is mainly used for counting purpose. It is used to find out number of lines, word count, byte and characters count in the files specified in the file arguments.
How do I get unique lines in Linux?
To find unique occurrences where the lines are not adjacent a file needs to be sorted before passing to uniq . uniq will operate as expected on the following file that is named authors. txt . As duplicates are adjacent uniq will return unique occurrences and send the result to standard output.
What does du command do in Linux?
The du command is a standard Linux/Unix command that allows a user to gain disk usage information quickly. It is best applied to specific directories and allows many variations for customizing the output to meet your needs.
How does grep work in Linux?
Grep is a Linux / Unix command-line tool used to search for a string of characters in a specified file. The text search pattern is called a regular expression. When it finds a match, it prints the line with the result. The grep command is handy when searching through large log files.
How do I find duplicate rows in Unix?
How to find duplicate records of a file in Linux?
- Using sort and uniq: $ sort file | uniq -d Linux. …
- awk way of fetching duplicate lines: $ awk ‘{a[$0]++}END{for (i in a)if (a[i]>1)print i;}’ file Linux. …
- Using perl way: …
- Another perl way: …
- A shell script to fetch / find duplicate records:
What does AWK do in bash?
AWK is a programming language that is designed for processing text-based data, either in files or data streams, or using shell pipes. In other words you can combine awk with shell scripts or directly use at a shell prompt. This pages shows how to use awk in your bash shell scripts.
What is the use of awk in Linux?
Awk is a utility that enables a programmer to write tiny but effective programs in the form of statements that define text patterns that are to be searched for in each line of a document and the action that is to be taken when a match is found within a line. Awk is mostly used for pattern scanning and processing.