Character input/output

• get_char(Stream,Char): Inputs a character (if Stream is a text stream) or a byte (if Stream is a binary stream) from the stream Stream, and unifies it with Char. After reaching the end of file, it unifies Char with end_of_file.

• get_char(Char): This is the same as get_char(Stream,Char), except that the current input stream is used.

• peek_char(Stream,Char): The current character in Stream is Char. The position pointer of Stream remains the same after this operation.

• peek_char(Char): This is the same as peek_char(Stream,Char), except that the current input stream is used.

• put_char(Stream,Char): Outputs the character Char to the stream Stream.

• put_char(Char): Outputs the character Char to the current output stream.

• nl(Stream): Outputs the new line character to the stream Stream.

• nl: Outputs the new line character to the current output stream.

• readLine(X): The call readLine(X) reads a line from the current input stream as character codes. Normally, the last character code is the end-of-line code (i.e., 10). After the end of the stream has been reached, X will be bound to []. (not in ISO).

• readFile(Name,Content): Reads a text file, and binds Content to the list of character codes in the file. (not in ISO).