File Reads and Writes
This article shows examples of file handling facilities in Fortress used in the this program: trunk/ProjectFortress/demos/tennisRanking.fss.
In order to use FileReadStream and FileWriteStream, trunk/Library/File.fsi must be imported:
The run function takes arguments from the command line:
and if the arguments are not appropriate, it prints the usage message:
Files can be opened for reads and writes by FileReadStream and FileWriteStream, respectively:
and they must be closed before ending the program:
The readLine method defined in FileReadStream returns the next available line from the stream (discarding line termination characters) and returns "" on EOF:
The example program defines two helper functions to read words from the stream:
Any Unicode characters can be read and written by the file stream utilities. For example, a sample input file trunk/ProjectFortress/demos/tennisGames includes Korean characters:
... begin 양소림 고아라 오채린 송은희 양소림 고아라 송은희 진선영 박승찬 변재섭 박승찬 송은희 지현수 양소림 ...
and a sample output file trunk/ProjectFortress/demos/tennis050307 includes Korean characters:
... Invalid game: 박승찬/오형식 vs 기철수/오왕열 has 32 ranking differences. Invalid game: 지현수 vs 변재섭 has played before. May 03, 2007 순위 선수 승패 경기수 포인트 ------------------------------------------------------------------- 1 김종성 26 / 15 (3 / 1) 41 (4) 2870 (130) 2 기철수 40 / 34 (5 / 7) 74 (12) 2785 (130) 3 오왕열 34 / 20 (6 / 1) 54 (7) 2610 (310) 4 박승찬 13 / 5 (7 / 1) 18 (8) 2425 (1025) ...
One frequently asked question is how to convert a string to an integer value. trunk/Library/FortressLibrary.fss defines strToInt for this functionality:
Finally, print is a varargs method that writes characters to the end of a FileStream:
and println is a varargs method that writes characters to the end of a FileStream, but in addition appends a final newline character "\n" at the same time.
