{"id":2834,"date":"2018-02-01T20:27:10","date_gmt":"2018-02-01T17:27:10","guid":{"rendered":"https:\/\/www.howtoforge.com\/linux-seq-command\/"},"modified":"2018-02-01T20:27:10","modified_gmt":"2018-02-01T17:27:10","slug":"linux-seq-command-tutorial-for-beginners-5-examples","status":"publish","type":"post","link":"https:\/\/afaghhosting.net\/blog\/linux-seq-command-tutorial-for-beginners-5-examples\/","title":{"rendered":"Linux seq Command Tutorial for Beginners (5 Examples)"},"content":{"rendered":"

Sometimes, you come across a command line tool that offers limited functionality on its own, but when used with other tools, you realize its actual potential. Once such tool is seq<\/strong>, which prints a sequence of numbers. In this tutorial, we will discuss the basics of this command line utility using easy to understand examples.<\/p>\n

But before jumping on to that, it’s worth mentioning that all examples in this article have been tested on an Ubuntu 16.04 machine.<\/p>\n

Linux seq command<\/h2>\n

As already mentioned, the seq command lets you print a sequence of numbers. Following is its syntax:<\/p>\n

seq [OPTION]… LAST
seq [OPTION]… FIRST LAST
seq [OPTION]… FIRST INCREMENT LAST<\/p>\n

And here’s how the tool’s man page explains it:<\/p>\n

 Print numbers from FIRST to LAST, in steps of INCREMENT. If FIRST or INCREMENT is omitted, it defaults to 1.\u00a0 That is, an omitted\u00a0 INCREMENT defaults to 1 even when LAST is smaller than FIRST.\u00a0 
The sequence of numbers ends when the sum of the current number and\u00a0 INCREMENT\u00a0 would\u00a0 become\u00a0 greater than LAST.\u00a0 FIRST, INCREMENT, and LAST are interpreted as floating point values.\u00a0 INCREMENT is usually positive if\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 FIRST\u00a0 is smaller than LAST, and INCREMENT is usually negative if FIRST\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 is greater than LAST.\u00a0 FORMAT must be suitable for printing\u00a0 one\u00a0 argu?\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 ment\u00a0 of type 'double'; it defaults to %.PRECf if FIRST, INCREMENT, and\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 LAST are all fixed point decimal numbers with maximum\u00a0 precision\u00a0 PREC,\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 and to %g otherwise.<\/p><\/pre>\n
Following are some Q&A-styled examples that should give you a better idea on how the seq command works.<\/p>\n
Q1. How seq command works?<\/h2>\n
Basic usage is very easy. All you have to do is to pass a number to seq, and the tool will producein output numbers from 1 to the input number.<\/p>\n
For example:<\/p>\n
seq 8<\/p>\n
\"How<\/a><\/p>\n
Of course, you can also specify the number from which you want the output to begin with.<\/p>\n
For example:<\/p>\n
seq 3 8<\/p>\n
\"Example<\/a><\/p>\n
Movin on, you can also set the incremental difference, which is 1 by default. For example, if you want seq to print from 1 to 9, but with a difference of 2, then here’s how you can do that:<\/p>\n
seq 1 2 9<\/p>\n
\"Another<\/a><\/p>\n
Q2. How to add a separator?<\/h2>\n
If you want, you can also have a separator to make the seq output look better. This feature is available through the -s<\/em><\/strong> command line option.<\/p>\n
For example, the following command intends to use a comma (,) as a separator:<\/p>\n
seq -s, 1 9<\/p>\n
\"How<\/a><\/p>\n
Q3. How to specify output format?<\/h2>\n
The seq command allows you to use printf style\u00a0floating-point FORMAT. This feature is accessible\u00a0through the -f<\/strong> command line option. The tool’s man page doesn’t have much information on how to use this option, but the info page contains the required details. Here’s what the info page says:<\/p>\n
`-f FORMAT'`--format=FORMAT'Print all numbers using FORMAT. FORMAT must contain exactly oneof the `printf'-style floating point conversion specifications`%a', `%e', `%f', `%g', `%A', `%E', `%F', `%G'. The `%' may befollowed by zero or more flags taken from the set `-+#0 '', thenan optional width containing one or more digits, then an optionalprecision consisting of a `.' followed by zero or more digits.FORMAT may also contain any number of `%%' conversionspecifications. All conversion specifications have the samemeaning as with `printf'.
The default format is derived from FIRST, STEP, and LAST. Ifthese all use a fixed point decimal representation, the defaultformat is `%.Pf', where P is the minimum precision that canrepresent the output numbers exactly. Otherwise, the defaultformat is `%g'.<\/p><\/pre>\n
For example, you can use this option in the following way:<\/p>\n
seq -f “%02g” 6<\/p>\n
Q4. How to use seq with other commands? (Use case 1)<\/h2>\n
Suppose you want to perform addition\u00a0of some numbers, say from 111 to 121. Here’s how you can do this using seq:<\/p>\n
expr `seq -s ” + ” 111 121`<\/p>\n
Here’s the above command in action:<\/p>\n
\"How<\/a><\/p>\n
Q5. How to use seq with other commands? (Use case 2)<\/h2>\n
Suppose you want to create a bunch of new files with names where only an integer value changes. For example, file1, file2, file3, and so on. Here’s how you can do this using seq.<\/p>\n
touch $(seq -f “file%g” 1 10)<\/p>\n
\"How<\/a><\/p>\n
Conclusion<\/h2>\n
So now you’ll agree how useful the seq command is. If you talk about the command line options Seq offers, there’s not much of a learning curve, just that you should know when and how to use the command and its options. We’ve covered several use cases here – should be enough to get you started with the tool. For more information on Seq, head to its man page<\/a>.<\/p>\n
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Sometimes, you come across a command line tool that offers limited functionality on its own, but when used with other tools, you realize its actual potential. Once such tool is seq, which prints a sequence of numbers. In this tutorial, we will discuss the basics of this command line utility using easy to understand examples. …<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[36],"tags":[],"class_list":["post-2834","post","type-post","status-publish","format-standard","hentry","category-36"],"_links":{"self":[{"href":"https:\/\/afaghhosting.net\/blog\/wp-json\/wp\/v2\/posts\/2834","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/afaghhosting.net\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/afaghhosting.net\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/afaghhosting.net\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/afaghhosting.net\/blog\/wp-json\/wp\/v2\/comments?post=2834"}],"version-history":[{"count":0,"href":"https:\/\/afaghhosting.net\/blog\/wp-json\/wp\/v2\/posts\/2834\/revisions"}],"wp:attachment":[{"href":"https:\/\/afaghhosting.net\/blog\/wp-json\/wp\/v2\/media?parent=2834"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/afaghhosting.net\/blog\/wp-json\/wp\/v2\/categories?post=2834"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/afaghhosting.net\/blog\/wp-json\/wp\/v2\/tags?post=2834"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}
\"How<\/a><\/p>\n