Linux od Command

last modified March 3, 2025

The od command in Linux is used to display the contents of a file in various formats, such as octal, hexadecimal, or ASCII. It is a powerful tool for inspecting binary files or understanding the raw data of a file. This tutorial covers basic and advanced usage of od with practical examples.

od is commonly used for debugging, analyzing binary files, and understanding file structures.

Display File in Octal Format

This example demonstrates how to display the contents of a file in octal format.

od filename.txt

The od command outputs the contents of filename.txt in octal format by default.

Display File in Hexadecimal Format

This example shows how to display the contents of a file in hexadecimal format.

od -x filename.txt

The -x option outputs the file contents in hexadecimal format.

Display File in ASCII Format

This example demonstrates how to display the contents of a file in ASCII format.

od -c filename.txt

The -c option outputs the file contents in ASCII format, showing printable characters and escape sequences.

Display File with Offset

This example shows how to display file contents with an offset.

od -A x -t x1 filename.txt

The -A x option displays the offset in hexadecimal, and -t x1 shows each byte in hexadecimal format.

Display File in Decimal Format

This example demonstrates how to display the contents of a file in decimal format.

od -t d1 filename.txt

The -t d1 option outputs the file contents in decimal format.

Display File with Custom Format

This example shows how to display file contents in a custom format.

od -t o2 filename.txt

The -t o2 option outputs the file contents in octal format, with 2 bytes per line.

Display File with No Offset

This example demonstrates how to display file contents without an offset.

od -A n filename.txt

The -A n option hides the offset in the output.

Display File with Limited Bytes

This example shows how to display only the first few bytes of a file.

od -N 16 filename.txt

The -N 16 option limits the output to the first 16 bytes of the file.

Display File with Custom Byte Grouping

This example demonstrates how to display file contents with custom byte grouping.

od -t x4 filename.txt

The -t x4 option groups the output into 4-byte hexadecimal values.

Display File with Multiple Formats

This example shows how to display file contents in multiple formats simultaneously.

od -t x1 -t c filename.txt

The -t x1 and -t c options display the file in hexadecimal and ASCII formats side by side.

Best Practices for od

• Use for Binary Files: Use od to inspect binary files and understand their structure.
• Combine with Other Commands: Use od with commands like grep or less for advanced processing.
• Customize Output: Use options like -t and -A to customize the output format.
• Limit Output: Use -N to limit the output for large files.

Source

GNU od Manual

In this article, we have explored various examples of using the od command for inspecting file contents in different formats, including octal, hexadecimal, and ASCII.

Author

My name is Jan Bodnar, and I am a passionate programmer with extensive programming experience. I have been writing programming articles since 2007. To date, I have authored over 1,400 articles and 8 e-books. I possess more than ten years of experience in teaching programming.

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