What is the difference between "* text=auto" and "* text=auto eol=lf"?

Question

I was reading about the .gitattributes file and the rule to force line endings in some tutorials it's written like * text=auto and in some others, it's like * text=auto eol=lf at the first line of the file.

Are there any differences? what does the first one exactly do? Does it even force any line endings?

Also in some repositories it's mentioned that * text=auto preforms LF normalization! I don't know whether it's true or not.

Pasteup

See https://mcmap.net/q/973463/-what-is-the-differrence-between-text-auto-and-text-eol-lf-in-gitattributes and https://mcmap.net/q/1775931/-what-39-s-the-difference-between-quot-text-auto-eol-lf-quot-and-quot-text-eol-lf-quot-in-gitattributes Found in stackoverflow.com/search?q=%5Bgitattributes%5D+text+auto+eol+lf – Methadone

Answer 1

There's a difference between these attributes. text asks Git to perform line ending conversion. Any time Git does this, it will store LF endings in the repository, and it will convert them when it checks files out in the working tree. text=auto asks Git to search the beginning of the file for a NUL byte, and if it finds one, then the file is binary and conversions are not performed; otherwise, the file is text, and conversions are performed. This usually works fine in most cases, and is a sensible default.

By default, Git honors several configuration variables to decide what line ending conversion should be used in the working tree (LF or CRLF), unless the eol attribute is set. If eol is set, then (a) the file is automatically set to be text and (b) that line ending is always used.

So in the former case, * text=auto says, "Guess whether this is a text file, and if it is, check this file out with the user's preferred line endings." The eol=lf applies only to files that are guessed as text in this case, as of Git 2.10. In general, eol applies if text is set explicitly, text=auto is set and the file is detected as text, or if text is left unspecified; in Git 2.10 and newer, it doesn't affect files explicitly marked -text or detected as binary with text=auto.

However, if you're using older versions of Git, this can cause some binary files to be mishandled, since it will force them to always be text. If your repository contains only text files, then it will work, but this is better written as * text eol=lf. Otherwise, you can specify different types of files separately:

* text=auto
*.c text
*.jpg -text
*.sh text eol=lf
*.bat text eol=crlf

The above sets shell files to LF because those are required for them to work, and likewise with batch files having CRLF endings. JPEG files won't have any conversion, since they're binary.

Misnomer

"In the latter case, the text=auto is ignored, and all files are text files and have LF endings in the working tree, as well as in the repository." Is this true for modern git versions? I see this changelog referenced frequently, where it's suggested that text=auto eol=whatever does not override the "auto" value for text: github.com/git/git/blob/master/Documentation/RelNotes/… – Ostium

This documentation says of eol, “It enables end-of-line conversion without any content checks, effectively setting the text attribute.” It may be that the behavior has changed, but the documented behavior is what I've specified. – Misnomer

Right, but it's important to note that since Git 2.10, text=auto is not ignored when you do text=auto eol=lf. (It just ends up being redundant.) – Ostium

I've gone ahead and updated the text based on the behavior that I've discovered by adding a test to Git. I'll be sending that test and a patch upstream relatively soon. – Misnomer

Great, thanks! Just to confirm, is my understanding accurate that * text=auto eol=lf is the same as * text=auto for Git 2.10+? That is, text files will get LF while binary files will remain untouched? Are you patching the Git docs to clarify this or? Just want to make sure I'm 100% clear on this behavior; I wrote the second article that OP referenced and am in the process of updating it to clarify this behavior so it's less confusing. – Ostium

* text=auto allows the user to specify the ending with core.autocrlf or core.eol. * text=auto eol=lf will always use LF endings. In neither case will binary files be modified. And yes, the branch I'll be pushing is here. – Misnomer

Let us continue this discussion in chat. – Ostium