"write a simple file"
file := 'myTestFile.txt' asFilename.
stream := file writeStream.
stream nextPutAll: 'Line 1'.
stream nextPut: Character cr.
stream nextPutAll: 'Line 2'.
stream nextPut: Character cr.
stream nextPutAll: 'Line 3'.
stream nextPut: Character cr.
stream close.

"read the entire file"
file := 'myTestFile.txt' asFilename.
contents := file contentsOfEntireFile.
^contents.

"read line by line"
file := 'myTestFile.txt' asFilename.
stream := file readStream.
lines := OrderedCollection new.
[stream atEnd]
	whileFalse: [| line |
		line := stream upTo: Character cr.
		lines add: line].
stream close.
^lines.

"finding the file"
directory := '.' asFilename.
files := directory filesMatching: 'myTest*'.
^files.

"More information - Browse this URL"
http://smalltalk.cincom.com/tutorial/version7/tutorial1/weblogstatstoc.htm