{"id":1861,"date":"2021-10-05T18:15:15","date_gmt":"2021-10-05T12:45:15","guid":{"rendered":"https:\/\/coimbatorewebhosting.com\/blog\/?p=1861"},"modified":"2021-10-05T18:15:15","modified_gmt":"2021-10-05T12:45:15","slug":"top-13-basic-cat-commands-in-linux","status":"publish","type":"post","link":"https:\/\/tiruppurwebhosting.com\/blog\/top-13-basic-cat-commands-in-linux\/","title":{"rendered":"Top 13 Basic Cat Commands in Linux"},"content":{"rendered":"

In this article, we are going to find out the handy use of cat<\/strong> commands with their examples in Linux<\/a>.<\/p>\n

\"13<\/p>\n

The cat<\/strong> (short for \u201cconcatenate<\/strong>\u201c) command is one of the most frequently used commands in Linux\/Unix-like operating systems. cat<\/strong> command allows us to create single or multiple files, view content of a file, concatenate files and redirect output in terminal or files.<\/p>\n

General Syntax of Cat Command<\/h4>\n
$ cat [OPTION] [FILE]...<\/pre>\n
1. Display Contents of File<\/h4>\n
The below example will show the contents of \/etc\/passwd<\/strong> file.<\/p>\n
# cat \/etc\/passwd\n\nroot:x:0:0:root:\/root:\/bin\/bash\nbin:x:1:1:bin:\/bin:\/sbin\/nologin\nnarad:x:500:500::\/home\/narad:\/bin\/bash<\/pre>\n
2. View Contents of Multiple Files in terminal<\/h4>\n
In below example, it will display the contents of the test<\/strong> and test1<\/strong> file in the terminal.<\/p>\n
# cat test test1\n\nHello everybody\nHi world,<\/pre>\n
3. Create a File with Cat Command<\/h4>\n
We will create a file called test2<\/strong> file with the below command.<\/p>\n
# cat >test2<\/pre>\n
<\/center><\/p>\n
\n
\n
\n
Awaits input from the user, type desired text, and press CTRL+D<\/strong> (hold down Ctrl key<\/strong> and type \u2018d<\/strong>\u2018) to exit. The text will be written the test2<\/strong> file. You can see the content of the file with the following cat<\/strong> command.<\/div>\n<\/div>\n<\/div>\n<\/div>\n
 <\/p>\n
# cat test2\n\nhello everyone, how do you do?<\/pre>\n
4. Use Cat Command with More & Less Options<\/h4>\n
If a file having a large number of content that won\u2019t fit in the output terminal and the screen scrolls up very fast, we can use parameters more and less with the cat<\/strong> command as shown below.<\/p>\n
# cat song.txt | more\n# cat song.txt | less<\/pre>\n
5. Display Line Numbers in File<\/h4>\n
With the -n<\/strong> option you could see the line numbers of a file song.txt<\/strong> in the output terminal.<\/p>\n
# cat -n song.txt\n\n1  \"Heal The World\"\n2  There's A Place In\n3  Your Heart\n4  And I Know That It Is Love\n5  And This Place Could\n6  Be Much\n7  Brighter Than Tomorrow\n8  And If You Really Try\n9  You'll Find There's No Need\n10  To Cry\n11  In This Place You'll Feel\n12  There's No Hurt Or Sorrow<\/pre>\n
6. Display $ at the End of File<\/h4>\n
In the below, you can see with the -e<\/strong> option that \u2018$<\/strong>\u2018 is shows at the end of the line and also in space showing \u2018$<\/strong>\u2018 if there is any gap between paragraphs. This option is useful to squeeze multiple lines into a single line.<\/p>\n
# cat -e test\n\nhello everyone, how do you do?$\n$\nHey, am fine.$\nHow's your training going on?$\n$<\/pre>\n
7. Display Tab Separated Lines in File<\/h4>\n
In the below output, we could see TAB<\/strong> space is filled up with the \u2018^I<\/strong>\u2018 characters.<\/p>\n
# cat -T test\n\nhello ^I<\/strong>everyone, how do you do?\n\nHey, ^I<\/strong>am fine.\n^I<\/strong>^IHow's your training ^I<\/strong>going on?\nLet's do ^I<\/strong>some practice in Linux.<\/pre>\n
8. Display Multiple Files at Once<\/h4>\n
In the below example we have three files test<\/strong>, test1,<\/strong> and test2,<\/strong> and able to view the contents of those files as shown above. We need to separate each file with ;<\/strong> (semicolon).<\/p>\n
# cat test; cat test1; cat test2\n\nThis is a test file\nThis is the test1 file.\nThis is test2 file.<\/pre>\n
9. Use Standard Output with Redirection Operator<\/h4>\n
We can redirect the standard output of a file into a new file else existing file with a \u2018><\/strong>\u2018 (greater than) symbol. Careful, existing contents of the test1<\/strong> will be overwritten by the contents of the test<\/strong> file.<\/p>\n
# cat test > test1<\/pre>\n
10. Appending Standard Output with Redirection Operator<\/h4>\n
Appends in existing file with \u2018>><\/strong>\u2018 (double greater than) symbol. Here, the contents of the test<\/strong> file will be appended at the end of the test1<\/strong> file.<\/p>\n
# cat test >> test1<\/pre>\n
11. Redirecting Standard Input with Redirection Operator<\/h4>\n
When you use the redirect with standard input \u2018<<\/strong>\u2018 (less than symbol), it uses file name test2<\/strong> as input for command and output will be shown in a terminal.<\/p>\n
# cat < test2\n\nThis is test2 file.<\/pre>\n
12. Redirecting Multiple Files Contain in a Single File<\/h4>\n
This will create a file called test3<\/strong> and all output will be redirected in a newly created file.<\/p>\n
# cat test test1 test2 > test3<\/pre>\n
13. Sorting Contents of Multiple Files in a Single File<\/h4>\n
This will create a file test4<\/strong> and the output of the cat<\/strong> command is piped to sort and the result will be redirected to a newly created file.<\/p>\n
# cat test test1 test2 test3 | sort > test4<\/pre>\n
This article shows the basic commands that may help you to explore the cat<\/strong> commands.<\/p>\n","protected":false},"excerpt":{"rendered":"
In this article, we are going to find out the handy use of cat commands with their examples in Linux. The cat (short for \u201cconcatenate\u201c) command is one of the most frequently used commands in Linux\/Unix-like operating systems. cat command allows us to create single or multiple files, view content of a file, concatenate files<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[148,92,9,149],"tags":[],"class_list":["post-1861","post","type-post","status-publish","format-standard","hentry","category-centos-7-rhel-7","category-general","category-linux","category-latest"],"_links":{"self":[{"href":"https:\/\/tiruppurwebhosting.com\/blog\/wp-json\/wp\/v2\/posts\/1861","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/tiruppurwebhosting.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/tiruppurwebhosting.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/tiruppurwebhosting.com\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/tiruppurwebhosting.com\/blog\/wp-json\/wp\/v2\/comments?post=1861"}],"version-history":[{"count":0,"href":"https:\/\/tiruppurwebhosting.com\/blog\/wp-json\/wp\/v2\/posts\/1861\/revisions"}],"wp:attachment":[{"href":"https:\/\/tiruppurwebhosting.com\/blog\/wp-json\/wp\/v2\/media?parent=1861"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/tiruppurwebhosting.com\/blog\/wp-json\/wp\/v2\/categories?post=1861"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/tiruppurwebhosting.com\/blog\/wp-json\/wp\/v2\/tags?post=1861"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}