Stata/Natural Language Processing
Reading a text file
If lines are short (less than the 244 string characters), one can use insheet. This command will read the text file into Stata's memory.
. insheet using toto.txt, clear
String functions
First have a look at the list of string functions already included in Stata.
. h string functions
Regular Expressions
Stata includes commands for regular expressions regexm(), regexr() and regexs().
Wordscores
Ken Benoit, Michael Laver and Will Lowe have developed wordscores, a set of Stata command which read textfiles, count the frequency of each word and compute some index of similarity between texts.