With Guess you can build a Jinx database from data which already
looks like a Jinx database.
You will be asked for the name of a file and a pattern.
With 
and 
you can step through names
and patterns entered earlier.
With TAB you can abort the Guess operation.
The specified file is opened for reading. Each line in the file is interpreted as a record and split into fields with the pattern. A descriptor with enough fields is generated. Fields are named field1, field2, etc. The constraint pattern for every field is `.*'.
You can make an example database with Guess using file /etc/passwd and pattern `:'.