Programming Fundamentals/Files/BASIC
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files.bas
[edit | edit source]' This program creates a file, adds data to the file, displays the file,
' appends more data to the file, displays the file, and then deletes the file.
' It will not run if the file already exists.
'
' References:
' https://www.mathsisfun.com/temperature-conversion.html
' https://en.wikibooks.org/wiki/BASIC_Programming
DECLARE SUB Main()
DECLARE SUB CreateFile(Filename AS STRING)
DECLARE SUB ReadFile(Filename AS STRING)
DECLARE SUB AppendFile(Filename AS STRING)
DECLARE SUB DeleteFile(Filename AS STRING)
DECLARE FUNCTION FileExists(Filename AS STRING) AS INTEGER
Main()
SUB Main()
CONST FILENAME = "~file.txt"
If FileExists(FILENAME) Then
PRINT "File already exists."
ELSE
CreateFile(FILENAME)
ReadFile(FILENAME)
AppendFile(FILENAME)
ReadFile(FILENAME)
DeleteFile(FILENAME)
END IF
END SUB
SUB CreateFile(Filename AS STRING)
DIM C AS SINGLE
DIM F AS SINGLE
OPEN Filename FOR OUTPUT AS #1
PRINT #1, "C" & CHR$(9) & "F"
FOR C = 0 TO 50
F = C * 9 / 5 + 32
PRINT #1, C & CHR$(9) & F
NEXT
CLOSE #1
END SUB
SUB ReadFile(Filename AS STRING)
DIM Text AS STRING
OPEN Filename FOR INPUT AS #1
DO WHILE NOT EOF(1)
INPUT #1, Text
PRINT Text
LOOP
CLOSE #1
PRINT
END SUB
SUB AppendFile(Filename AS STRING)
DIM C AS SINGLE
DIM F AS SINGLE
OPEN Filename FOR APPEND AS #1
FOR C = 51 TO 100
F = C * 9 / 5 + 32
PRINT #1, C & CHR$(9) & F
NEXT
CLOSE #1
END SUB
SUB DeleteFile(Filename AS STRING)
KILL Filename
END SUB
'FileExists checks to see if Filename exists and has content.
FUNCTION FileExists(Filename AS STRING) AS INTEGER
OPEN Filename FOR INPUT AS #1
FileExists = NOT EOF(1)
CLOSE #1
END FUNCTION
Try It
[edit | edit source]Copy and paste the code above into one of the following free online development environments or use your own BASIC compiler / interpreter / IDE.