INPUT (file mode)

See OPEN.

The INPUT file mode in an OPEN statement opens an existing file for INPUT (file statement).

Syntax

OPEN fileName$ FOR INPUT AS #filenumber%

• If fileName$ does not exist, attempting to open it FOR INPUT will create a program ERROR Codes. Use _FILEEXISTS to avoid errors.
• The file number can be determined automatically by using a FREEFILE variable value.
• Mode can use INPUT (file statement) #, LINE INPUT (file statement) # or INPUT$ to read the file data.
• Use the EOF function to avoid reading data past the end of a file and creating an ERROR Codes.
• Input file statements will use the same file number as the OPEN statement.
• The INPUT mode allows the same file to be opened in another mode with a different number.
• NOTE: LINE INPUT (file statement) will work faster in BINARY than INPUT mode in QB64 to stay compatible with QBasic.

Example(s)

Avoiding an INPUT mode or INPUT (file statement) read error using a FileExist function. QB64 can use the _FILEEXISTS function.

 DIM Fdata$(100)
 INPUT "Enter data file name: ", datafile$
 IF _FILEEXISTS(datafile$) THEN
    D% = FREEFILE: count = 0
    OPEN datafile$ FOR INPUT AS #D%
    DO UNTIL EOF(D%)
     count = count + 1
     LINE INPUT #D%, Fdata$(count)
     IF count = 100 THEN EXIT DO  ' don't exceed array size!
    LOOP
  CLOSE #D%
 ELSE : PRINT "File not found!"
 END IF

Explanation: The _FILEEXISTS function is used before OPEN datafile$ FOR INPUT AS #D%, which would generate an error in case the file didn't exist.

See Also

• INPUT (file statement), LINE INPUT (file statement), INPUT$ (file input)
• INPUT, LINE INPUT, INPUT$ (keyboard input)
• APPEND, RANDOM, OUTPUT, BINARY
• READ, DATA
• _FILEEXISTS, _DIREXISTS