From the comment:
// CheckTrailingGarbage tries to read one byte from stdin and exits with a
// fatal error if the read returns any data.
// This is meant to be called after reading the password, when there is no more
// data expected. This helps to catch problems with third-party tools that
// interface with gocryptfs.
Before:
You can now mount it using: gocryptfs a x MOUNTPOINT
After:
You can now mount it using: gocryptfs "a x" MOUNTPOINT
This is still not bulletproof but should handle the common
case of having a space in the directory name. After all,
it's only a suggestion.
$ gocryptfs -init -extpass "echo test" a
Using password provided via -extpass. <<< DUPLICATE
Reading password from extpass program
The gocryptfs filesystem has been created successfully.
You can now mount it using: gocryptfs a MOUNTPOINT
