I’m not a fan of Subversion but it exists in my life nonetheless. To that end, sometimes you may need to write tools against it. Sometimes these tools may need to differentiate between binary and text entries. Since SVN needs to know, at the very least, whether a file is text or binary (because most version-control systems depend on taking deltas of text-files), it’s reasonable to think that you can read this information from SVN.
This information may be stored as a property on each entry. Note that though there appears to be no guarantee that this information is available, I consider it to be reasonable to expect that a binary file will always have a non-empty mime-type.
The mime-type of an image:
$ svn propget svn:mime-type image.png application/octet-stream $ echo $? 0
The mime-type of a plain-text file:
$ svn proplist config.xml $ echo $? 0
Notice that you’ll get a successful return (0) whether that property is or is not defined.
You can also read the property off remote files in the same fashion:
$ svn propget svn:mime-type https://subversion.host/image.png application/octet-stream