With SharpBASIC data can be read from and written to files on disk. SharpBASIC supports three different file types: text files, binary files and random access files. There are several functions and statements to handle files.

The open function is used to open a file:

handle = open(inp "myfile.txt");

The function accepts a filename preceded by a mode clause. In the example, a file is opened for input (inp), which is the mode to read text files. There are five different mode types:

• inp - input to read from text files
• out - output to create and write to text files
• add - to add (append) to text files
• bin - binary to read from and write to binary files
• ran - random to read from and write to random access files

The open function returns a file handle of type hnd, which is a non-negative integer number if the file was opened successfully.

The close statement is used to close a file that was previously opened with the open function.

close(handle);

The close statement accepts a valid file handle of type hnd as parameter.

The read function is used to read text from a text file.

flag = read(handle, text);

The read function accepts two parameters: a valid handle of a text file that was opened for input and a variable or fixed-length string where the text will be stored. The function returns a flag of type integer that is 0 (null) if the read operation was successful:

flag = read(handle, text);
if flag == 0 do
  print(text);
end

If the string is a variable (null-terminated) length-string then the read function will try to read the next line in the file. If the string is a fixed-length string then the read function will read the next block of text the size of the string. This means that if a fixed-length string is long enough, a text-file can be read at once.

The write function is used to write text to a text file.

flag = write(handle, text);

The function accepts two parameters: a valid handle of a text file that was opened for output (out) or append(add) and a string expression. The function returns a flag of type integer that is 0 (null) if the write operation was successful:

flag = write(handle, text);
if flag <> 0 do
  print("Error writing to file.");
end