Linux seq Command Explained with Examples for Beginners

Introduction

The seq command in Linux is a simple yet powerful tool used to generate sequences of numbers. It’s often used in scripting, automation, and quick number generation. Whether you want to print a range of numbers or format them with specific options, seq can help.

Basic Usage of seq

1. Generate a Simple Sequence

Here, seq 10 prints numbers from 1 to 10.

2. Specify a Start and End Number

This prints numbers starting at 3 and ending at 10.

3. Use Step Values

The middle number (3) specifies the step. So this command prints every third number from 1 to 20.

4. Print Numbers on One Line

The -s option changes the separator, in this case to a space.

5. Format Numbers with Leading Zeros

The -w option ensures equal width by padding numbers with leading zeros.

6. Using seq in a loop (practical example)

for i in $(seq 1 3); do
  echo "File_$i.txt"
done

Output:

File_1.txt
File_2.txt
File_3.txt

The seq command can be used in a loop to create patterns for complex actions.

Why Use seq?

• Quick number generation for loops in shell scripts
• Creating test data
• Formatting sequences with custom separators
• Automating repetitive tasks

Conclusion

The Linux seq command is a handy utility for generating sequences of numbers in different formats. Once you master its options, you can save time in scripting and automation tasks.

References:

1. Ubuntu Manpages