How do you sort and count data with Linux commands?

Linux commands are powerful tools for system administrators who need to manipulate, analyze, and process large amounts of data. In this article, you will learn how to use some common Linux commands to sort and count data in different ways. You will also see some examples of how to combine these commands with pipes and filters to create more complex queries and reports.

1 Sorting data

The sort command can sort the lines of a text file or a standard input stream according to various criteria, such as alphabetical, numerical, reverse, or random order. You can also specify a field or a character position to sort by, or use a custom delimiter to separate the fields. For example, to sort a file called names.txt by the second field, which is the last name, using a comma as the delimiter, you can run: sort -t, -k2 names.txt To sort the same file in reverse order by the third field, which is the age, you can run: sort -t, -k3 -r names.txt

Add your perspective

2 Counting data

The wc command can count the number of lines, words, and bytes in a text file or a standard input stream. You can use different options to display only one of these counts, or to print the total count for multiple files. For example, to count the number of lines in a file called log.txt, you can run: wc -l log.txt To count the number of words in all the files in the current directory, you can run: wc -w *

Add your perspective

3 Combining commands

You can use pipes and filters to combine multiple commands and perform more advanced operations on data. A pipe is a symbol (|) that redirects the output of one command to the input of another command. A filter is a command that modifies or selects data based on certain criteria. For example, to sort the output of the wc command by the number of lines in descending order, you can use the sort command with the -n and -r options, and pipe the output of wc to sort: wc -l * | sort -n -r To count the number of unique lines in a file called data.txt, you can use the sort command to sort the lines, and then use the uniq command to filter out the duplicate lines. The uniq command can also count the number of occurrences of each line with the -c option. You can pipe the output of sort to uniq: sort data.txt | uniq -c

Add your perspective

Diego Zuniga, M.Sc.

Infrastructure Platform Engineer @ JPMorganChase Linux Engineer - LPIC2 | CKAD | Terraform | LFCS | Splunk | RegEx Enthusiast | Passionate for Innovation & Automation
Report contribution
The sort command also have an option to filter unique results and deduplicate values, is not needed to use "uniq". Instead of, use like follows: # sort -u data.txt

Like

4 Searching data

The grep command can search for a pattern in a text file or a standard input stream, and print the matching lines. You can use regular expressions to define more complex patterns, and various options to control the output format, such as showing the line numbers, the file names, or the context of the matches. For example, to search for the word "error" in all the files in the current directory, and show the file name and the line number for each match, you can run: grep -n -H error * To search for lines that start with a capital letter in a file called text.txt, and show the two lines before and after each match, you can run: grep -B2 -A2 '^[A-Z]' text.txt

Add your perspective

Diego Zuniga, M.Sc.

Infrastructure Platform Engineer @ JPMorganChase Linux Engineer - LPIC2 | CKAD | Terraform | LFCS | Splunk | RegEx Enthusiast | Passionate for Innovation & Automation
(edited)
Report contribution
- Try to finding the word "error" (take into consideration that may return results like "iserror_" or any word that contains the error word, if you want to filter exactly error word, use word boundaries \b\b) Also, personally I do not use wildcard and use the option "recursive" -> r. # grep -nr "error" /parent_folder For the second example, I prefer to use "context" option instead to use after A/before B options in grep, it gives the same amount of lines after and above the match. - So, the entire command could be like that: # grep -C 2 "^[A-Z]" text.txt

Like

5 Comparing data

The diff command can compare two files or two directories, and show the differences between them. You can use different options to customize the output format, such as showing the changes in a unified or a side-by-side style, or highlighting the differences with colors. For example, to compare two files called file1.txt and file2.txt, and show the differences in a unified format with three lines of context, you can run: diff -u3 file1.txt file2.txt To compare two directories called dir1 and dir2, and show the differences in a side-by-side format with colors, you can run: diff -y --color dir1 dir2

Add your perspective

6 Here’s what else to consider

This is a space to share examples, stories, or insights that don’t fit into any of the previous sections. What else would you like to add?

Add your perspective

How do you sort and count data with Linux commands?

1

2

3

4

5

6

1 Sorting data

2 Counting data

3 Combining commands

4 Searching data

5 Comparing data

6 Here’s what else to consider

System Administration

Rate this article

Thanks for your feedback

More articles on System Administration

More relevant reading

How do you sort and count data with Linux commands?

1

2

3

4

5

6

1 Sorting data

2 Counting data

3 Combining commands

4 Searching data

5 Comparing data

6 Here’s what else to consider

System Administration

Rate this article

Thanks for your feedback

Explore Other Skills