What does git diff –ignore-cr-at-eol do?

git diff --ignore-cr-at-eol is a command used in the version control system Git, and the --ignore-cr-at-eol option tells Git to overlook changes that occur solely at the end of lines. To understand this command better, let’s first break down what each part of the command means:

  • git diff: This is the command that shows changes between commits, commit and working tree, etc.
  • --ignore-cr-at-eol: This is a flag that modifies the behavior of git diff. The cr stands for “carriage return” and eol stands for “end of line.”

Traditionally, different operating systems have different ways of representing the end of a line in a text file:

  • Unix systems (like Linux and MacOS) use the linefeed character (LF, represented as ‘\n’).
  • Windows uses a combination of carriage return and linefeed (CRLF, represented as ‘\r\n’).

When you’re working in a team where some developers use Unix-based systems and others use Windows, this can lead to confusing diffs. Even if no actual changes were made to the file, the diffs could show every line as changed because the line endings flip from LF to CRLF or vice versa.

This is where the --ignore-cr-at-eol option comes in handy. By using this option, Git will ignore changes that are solely changes from LF to CRLF or vice versa.

This way, only meaningful changes (like changes to the code or text in a file) will show up in the git diff output, making it easier to see what has actually been modified.

It’s worth noting that the --ignore-cr-at-eol option is not a default setting in Git, and it needs to be explicitly added whenever needed.

It’s also important to consider setting a consistent line ending policy for your team or project to minimize these issues. This can be done using .gitattributes file settings or global git configurations. But, for a quick overlook of differences without the noise of line ending changes, git diff --ignore-cr-at-eol is your command to go with.