How to compare, with git diff, two remote files which are not in a repository?

Question

I can compare two remote files with diff and ssh:

diff <(ssh machine1 "sudo cat ${FILE}") <(ssh machine2 "sudo cat ${FILE}")

but if I try with git diff,

git diff --no-index --color-words <(ssh machine1 "sudo cat ${FILE}") <(ssh machine2 "sudo cat ${FILE}")

I obtain:

error: /dev/fd/14: unsupported file type
fatal: cannot hash /dev/fd/14

How can I, with git diff, compare two remote files not in a repository ?

== Update ==

This question is not about substituting git diff by diff and colordiff, but about using git diff --no-index through ssh.

git diff doesn't seem to work with process substitution, see [this](https://stackoverflow.com/q/22706714/10155936), why not just use diff ? — Saurabh P Bhandari, Apr 20 '20 at 12:26
I prefer to use `git diff`, it has better output formatting. — Ortomala Lokni, Apr 20 '20 at 13:03
You can make `diff` output like `git diff`, see [this](https://stackoverflow.com/q/4857310/10155936) — Saurabh P Bhandari, Apr 20 '20 at 13:07

score 2 · Accepted Answer · edited Apr 20 '20 at 17:53

2

Since process substitution cannot be used because of a forgotten patch, the only option (since you want to use git diff) is :

ssh machine1 "sudo cat ${FILE}" > temp1 
ssh machine2 "sudo cat ${FILE}" > temp2
git diff --no-index temp1 temp2

You can achieve the same using diff (it maintains formatting and colors similar to git diff) which works with process substitution too

diff -u --color <(ssh machine1 "sudo cat ${FILE}") <(ssh machine2 "sudo cat ${FILE}")

edited Apr 20 '20 at 17:53

Ortomala Lokni

answered Apr 20 '20 at 15:21

@OrtomalaLokni `&&` indicates that the second ssh command will run only if the first one completes successfully. However, it is not required in this case and I have edited it. Regarding process substitution, [this](https://stackoverflow.com/q/22706714/10155936) explains it clearly – Saurabh P Bhandari Apr 20 '20 at 16:59

score 0 · Answer 2 · answered Apr 20 '20 at 12:21

0

Try using

git diff --no-index <(ssh machine1 "sudo cat ${FILE}") <(ssh machine2 "sudo cat ${FILE}")

As found here.

answered Apr 20 '20 at 12:21

wederer

Same problem, same error message. I've updated my question. – Ortomala Lokni Apr 20 '20 at 12:22
I'm looking how to show colorized character differences. – Ortomala Lokni Apr 20 '20 at 12:34
1

@OrtomalaLokni you are probably looking for `diff -u --color <(ssh machine1 "sudo cat ${FILE}") <(ssh machine2 "sudo cat ${FILE}")` – Saurabh P Bhandari Apr 20 '20 at 12:40
I have `diff: unrecognized option --color`, on macOS. – Ortomala Lokni Apr 20 '20 at 12:41
@OrtomalaLokni there are other options too, see [this](https://stackoverflow.com/q/8800578/10155936) – Saurabh P Bhandari Apr 20 '20 at 12:44

2 Answers2