I want to compare two folders using the diff command in Terminal.
One is on an external drive called “Seagate_181110_8TB_Drive”, and the folder is called “verified_saved_on_190109_HDD”.
The other is on a different external drive called “190109_HDD” and the folder is called “verified_from_Seagate_181110_8TB_Drive”.
What is the correct syntax for that command?
The -w flag can be handy for plain text files because it tells diff to ignore white space when comparing files. And of course you can use a full path to the files to compare.
diff (file input 1) (file input 2)
You can see more from the terminal, copy and paste:
man diff | more
Using the -rq flag because -r means it is recursive to include subdirectories, and -q simplifies the command output to only the differences shown.
Hi leroydouglas,
Thank you for that. I have tried that but no joy.
$ diff verified_saved_on_190109_HDD verified_from_Seagate_181110_8TB_Drive
diff: verified_saved_on_190109_HDD: No such file or directory
diff: verified_from_Seagate_181110_8TB_Drive: No such file or directory
I think it is because they are on external volumes. How do I set the command for the different volumes?
Show the mounted drives on the desktop.
From here you can drag the drive to the terminal—This will automatically place the path to the drive, then complete the path/with the specific file or folder you are comparing.
blank spaces need to be escaped( \) , dragging and dropping the drive will do it for you
ex.
/Volumes/Install\ macOS\ Mojave
OK, no errors so far and the folders are 1.3 TB each (give or take a few MB) so this will take some time I am sure. I'll report back if it fails. So far, I am thinking no news is good news.
I entered this: diff -rq /Volumes/190109_HDD/181110_8TB_Drive_contents_2/verified_from_Seagate_181110_8TB_Drive /Volumes/Seagate_181110_8TB_Drive/verified_saved_on_190109_HDD
and got this (so far): Only in /Volumes/190109_HDD/181110_8TB_Drive_contents_2/verified_from_Seagate_181110_8TB_Drive: .DS_Store
It just found my first difference so it is definitely doing what it is meant to. Thank you @leroydouglas.
It just found my first difference so it is definitely doing what it is meant to.
Good computing Mr. Spock !
I see you have your answer, but for a GUI method, see: http://kdiff3.sourceforge.net
diff terminal command
