File Input Output in ALGOL 60

File Input Output

in ALGOL 60

Welcome to the File Input Output in ALGOL 60 page! Here, you'll find the source code for this program as well as a description of how the program works.

Current Solution

begin
    comment ALGOL 60 really doesn't support file I/O, per se. It supports
        I/O via a channel number. With GNU MARST, an environment variable
        called FILE_<n> can be used to specify the file name for channel
        number n. Channel 3 is mapped to "output.txt".

        ALGOL 60 doesn't handle EOF (End-Of-File) gracefully. Instead it
        throws a fatal error and exits. To simulate an EOF, use the EOT
        (End-Of-Transmission) character (4);

    procedure outFile;
    begin
        comment A silly poem about ALGOL 60;
        outstring(3, "Travel back to ALGOL 60,\n");
        outstring(3, "Kind of simple, kind of nifty!\n");
        outstring(3, "But ponder with me for a while,\n");
        outstring(3, "Why it crashes on End-Of-File!\n");
        outstring(3, "\n");
        outstring(3, "A special symbol you will need,\n");
        outstring(3, "If you ever hope to succeed!\n");
        outstring(3, "What should we use, now let me see?\n");
        outstring(3, "Perhaps, per chance, an E-O-T!\n");
        outstring(3, "\x04")
    end outFile;

    integer procedure inFileAsciiChar;
    begin
        integer ch;

        comment For some reason '%' needs to be represented as '\x25'.
            Also, extra single quote needed to close backtick in string;
        inchar(
            3,
            "\x01\x02\x03\x04\x05\x06\x07\x08\t\n\x0b\x0c\r\x0e\x0f"
            "\x10\x11\x12\x13\x14\x15\x16\x17\x18\x19\x1a\x1b\x1c\x1d\x1e\x1f"
            " !\"#$\x25&'()*+,-./0123456789:;<=>?@ABCDEFGHIJKLMNO"
            "PQRSTUVWXYZ[\\]^_`abcdefghijklmnopqrstuvwxyz{|}~\x7f'",
            ch
        );
        if ch >= 129 then ch := 0;
        inFileAsciiChar := ch
    end inFileAsciiChar;

    comment Read file until newline, EOT, or buffer full.
        Return number of characters read;
    integer procedure inFileLine(buffer, bufsize);
    value bufsize;
    integer array buffer;
    integer bufsize;
    begin
        integer n, ch;
        n := 0;
    lineloop:
        ch := inFileAsciiChar;
        n := n + 1;
        buffer[n] := ch;
        if ch != 4 & ch != 13 & n < bufsize then goto lineloop;

        inFileLine := n
    end inFileLine;

    comment Read file a line at a time and output each line until EOT;
    integer procedure inFileAndOutput;
    begin
        integer array buffer[1:256];
        integer buflen;
    inloop:
        buflen := inFileLine(buffer, 256);
        outCharArray(buffer, buflen);
        if buffer[buflen] != 4 then goto inloop
    end inFile;

    procedure outAsciiChar(ch);
    value ch;
    integer ch;
    begin
        comment For some reason '%' needs to be represented as '\x25'.
            Also, extra single quote needed to close backtick in string;
        outchar(
            1,
            "\x01\x02\x03\x04\x05\x06\x07\x08\t\n\x0b\x0c\r\x0e\x0f"
            "\x10\x11\x12\x13\x14\x15\x16\x17\x18\x19\x1a\x1b\x1c\x1d\x1e\x1f"
            " !\"#$\x25&'()*+,-./0123456789:;<=>?@ABCDEFGHIJKLMNO"
            "PQRSTUVWXYZ[\\]^_`abcdefghijklmnopqrstuvwxyz{|}~\x7f'",
            ch
        )
    end outAsciiChar;

    procedure outCharArray(s, len);
    value len;
    integer array s;
    integer len;
    begin
        integer i;
        for i := 1 step 1 until len do outAsciiChar(s[i])
    end outCharArray;

    outFile;
    inFileAndOutput
end

File Input Output in ALGOL 60 was written by:

• rzuckerm

If you see anything you'd like to change or update, please consider contributing.

How to Implement the Solution

No 'How to Implement the Solution' section available. Please consider contributing.

How to Run the Solution

No 'How to Run the Solution' section available. Please consider contributing.