You have to edit one file from a repository but there are hundreds of files in that repository with possible hundreds of MB or GB worth of information. Not only that but you might need the file on a specific revision number.
You have tried
[php]svn checkout http://svn.source/directory/file.fil[/php]
But this doesn’t work.
You need to check out an empty directory from repository and then apply an update to the file you need.
[php]svn checkout –depth=empty htt://svn.source/directory[php]
Now you submit the update command for the file you need checked out
[php]svn update file.fil[/php]
note, before running the svn update make sure you “cd” to the directory that you just checked out from svn “cd /directory”.
finally if you want the file to a specific revision number all you have to do is run an update again with the revision number.
[php]svn update -r### file.fil[/php]