dos2unix - Linux

Overview

dos2unix is a command-line utility used to convert text files with DOS or Mac line endings (CR/LF or CR) into Unix/Linux format (LF), making them compatible with various Unix-based systems. This command is particularly useful when transferring text files from Windows (or old Mac systems) to Unix/Linux systems, ensuring that the files maintain their intended formatting and functionality without line-ending issues.

Syntax

The basic syntax for dos2unix is:

dos2unix [options] [file ...] [-n infile outfile ...]

file: Specify the file or files to be converted. If no files are mentioned, dos2unix will read from standard input.

Conversion Modes:

In-place conversion:
dos2unix file1.txt
Specifying input and output files:
dos2unix -n input.txt output.txt

Options/Flags

-o, –oldfile: Write conversion result back to the input file (in-place conversion).
-n, –newfile infile outfile: Convert infile to outfile. Unlike -o, this does not modify the input file.
-b, –keep-bom: Keep a Byte Order Mark if it is present. Useful for UTF-8 encoded files.
-r, –remove-bom: Remove any Byte Order Mark.
-k, –keepdate: Keep the original file date. By default, the file date is updated.
-f, –force: Force conversion of binary files.
-s, –safe: Skip binary files (safety for preventing corruption).
-c, –convmode convmode: Set conversion mode (ascii, 7bit, iso, mac).
-d, –info: Display file information instead of converting.

Examples

Basic Conversion:
Convert a single file in-place from DOS to Unix format.
```
dos2unix file1.txt
```
Multiple Files Conversion:
Convert multiple files simultaneously.
```
dos2unix file1.txt file2.txt file3.txt
```
Using New File Mode:
Create a new file with Unix line endings from a DOS-formatted file.
```
dos2unix -n dosfile.txt unixfile.txt
```
Keeping the Original File Date:
```
dos2unix -k file1.txt
```

Common Issues

Binary File Corruption:
Be cautious with dos2unix on binary files. Use -s option to skip binary files or -f to force conversion if absolutely necessary.
Permission Errors:
Ensure you have proper permissions on files you’re attempting to convert.
No Visible Changes:
Sometimes, no changes are visible after running the command. Ensure you are viewing the file in a Unix-compatible editor.

Integration

dos2unix can be combined with other Unix tools for powerful scripting and batch processing:

find /path/to/files -type f -name "*.txt" -exec dos2unix {} \;

This command would find and convert all .txt files under /path/to/files to have Unix line endings.

unix2dos: Converts Unix text files to DOS format, useful for reverting changes or sharing files with Windows-based systems.

For further information and the latest updates, you can visit the dos2unix official documentation.