How to use the command 'nkf' (with examples)

The ’nkf’ command, short for Network Kanji Filter, is a versatile tool used for converting kanji code from one encoding to another. Whether you need to convert to UTF-8 encoding, SHIFT_JIS encoding, change new line codes, or decrypt mime files, ’nkf’ has got you covered. This article will provide a clear understanding of each use case and how to use them effectively.

Use case 1: Convert to UTF-8 encoding

Code:

$ nkf -w path/to/file.txt

Motivation: The motivation for this use case can be to ensure that the text file is encoded in UTF-8, which is a widely used character encoding for international compatibility. This is particularly useful when working with files that contain characters from various languages.

Explanation: The -w option in the command specifies the target encoding as UTF-8. The path/to/file.txt argument represents the file path that needs to be converted.

Example output: The file.txt is now encoded in UTF-8 format.

Use case 2: Convert to SHIFT_JIS encoding

Code:

$ nkf -s path/to/file.txt

Motivation: This use case can be handy when dealing with Japanese text files that require encoding in SHIFT_JIS. SHIFT_JIS is widely used in Japan for text encoding and is essential for proper display and compatibility of Japanese characters.

Explanation: The -s option specifies the target encoding as SHIFT_JIS. The path/to/file.txt argument represents the file path that needs to be converted.

Example output: The file.txt is now encoded in SHIFT_JIS format.

Use case 3: Convert to UTF-8 encoding and overwrite the file

Code:

$ nkf -w --overwrite path/to/file.txt

Motivation: Overwriting the original file with the newly converted version can be useful when you want to replace the original file with the converted one and maintain the same filename.

Explanation: The -w option specifies the target encoding as UTF-8. The --overwrite option enables the command to overwrite the original file. The path/to/file.txt argument represents the file path that needs to be converted.

Example output: The file.txt is now encoded in UTF-8 format, and the original file is replaced with the converted version.

Use case 4: Set new line code to LF and overwrite (UNIX type)

Code:

$ nkf -d --overwrite path/to/file.txt

Motivation: Setting the new line code to LF (Line Feed) is commonly used for UNIX-based systems, ensuring compatibility and correct line endings when working with text files.

Explanation: The -d option sets the new line code to LF (UNIX type). The --overwrite option enables the command to overwrite the original file. The path/to/file.txt argument represents the file path that needs to be converted.

Example output: The file.txt’s new line code is now LF, and the original file is replaced with the converted version.

Use case 5: Set new line code to CRLF and overwrite (Windows type)

Code:

$ nkf -c --overwrite path/to/file.txt

Motivation: Setting the new line code to CRLF (Carriage Return, Line Feed) is primarily used for Windows systems, ensuring compatibility and correct line endings when working with text files.

Explanation: The -c option sets the new line code to CRLF (Windows type). The --overwrite option enables the command to overwrite the original file. The path/to/file.txt argument represents the file path that needs to be converted.

Example output: The file.txt’s new line code is now CRLF, and the original file is replaced with the converted version.

Use case 6: Decrypt mime file and overwrite

Code:

$ nkf -m --overwrite path/to/file.txt

Motivation: This use case is applicable when you have a mime file that needs to be decrypted and converted to its original form.

Explanation: The -m option enables the command to decrypt and convert a mime file. The --overwrite option allows overwriting the original file. The path/to/file.txt argument represents the file path that needs to be decrypted.

Example output: The mime file is successfully decrypted and converted to its original form, and the original file is replaced with the decrypted version.

Conclusion:

The ’nkf’ command is a powerful tool for converting kanji code from one encoding to another. Whether it’s converting to different encodings, setting new line codes or decrypting mime files, ’nkf’ provides all the necessary options. Understanding the different use cases and how to use them effectively will allow you to efficiently manage your file encodings and ensure compatibility with different systems.