pstbn

<?php

/*pstbn.php version 1.0.1*/

function msg(string $msg): void{    //small message to notify user of an error or whatever else
    echo("<html><head><link href=\"style.css\" rel=\"stylesheet\" type=\"text/css\"></head><body><code>$msg</code></body></html>");
}

function validatePaste(): bool{
    $paste_limit = 8192;
    $desc_limit = 256;

    if($_POST["paste"]){    //check for content
        $paste_len = strlen($_POST["paste"]);   //get length of paste
        $desc_len = ($_POST["desc"]) ? strlen($_POST["desc"]) : 0;  //get length of description

        if($paste_len <= $paste_limit){ //validate paste length
            if($desc_len <= $desc_limit){   //validate description length
                return true;
            }
            else{
                msg("ERROR: Description limit is $desc_limit chars. Your description if $desc_len chars.");
            }
        }
        else{
            msg("ERROR: Paste limit is $paste_limit chars. Your paste is $paste_len chars.");
        }
    }
    else{
        msg("ERROR: No content found.");
    }
    return false;
}

function createPaste(string $paste, string $desc): ?int{
    $max_pastes = 128;
    $lastID_file = "p/lastID.dat";

    //encode into json
    if($list = json_encode(["paste" => $paste, "size" => strlen($paste), "description" => $desc, "timestamp" => time()], true)){
        if($fp = fopen($lastID_file, "r+")){    //open lastID file
            $pasteID = (int)(file_get_contents($lastID_file) + 1);  //get pasteID

            if($pasteID > $max_pastes){ //check paste-count limit
                msg("Paste limit of $max_pastes pastes has been reached.");
                fclose($fp);
                return null;
            }

            fwrite($fp, (string)$pasteID);  //update lastID
            fclose($fp);

            $paste_file = "p/" . $pasteID . ".json";

            if($fp = fopen($paste_file, "w")){  //create paste file
                fwrite($fp, $list); //write paste and meta-data to file
                fclose($fp);

                return $pasteID;
            }
            else{
                msg("ERROR: Failed to open paste file ($paste_file).");
            }
        }
        else{
            msg("ERROR: Failed to open lastID file ($lastID_file).");
        }
    }
    else{
        msg("ERROR: JSON parsing error.");
    }
    return null;
}

function viewPaste(int $pasteID): bool{
    $paste_file = "p/" . $pasteID . ".json";

    if(file_exists($paste_file)){   //check if paste exists
        if($paste_data = json_decode(file_get_contents($paste_file), true)){    //obtain paste data
            $paste = htmlspecialchars($paste_data["paste"]);    //parse paste
            $description = htmlspecialchars($paste_data["description"]);    //parse description

            //send web page
            echo("
                <html>
                    <head>
                        <link href=\"style.css\" rel=\"stylesheet\" type=\"text/css\">
                    </head>
                    <body>
                        <h2>description</h2>
                        <p>" . $description . "<p>
                        <h2>paste</h2>
                        <p><b>timestamp:</b>&nbsp;" . $paste_data["timestamp"] . "&nbsp;|
                        <b>size:</b>&nbsp;" . $paste_data["size"] . "&nbsp;(bytes)&nbsp;|
                        <a href=\"\">permalink</a></p>
                        <pre>" . $paste . "</pre>
                    </body>
                </html>
            ");
            return true;
        }
        else{
            msg("ERROR: JSON parsing error.");
        }
    }
    else{
        msg("ERROR: Failed to open paste file ($paste_file). Paste likely doesn't exist.");
    }
    return false;
}

/*==========Main==========*/

if($_POST){ //check for POST
    if(validatePaste()){    //validate
        if($pasteID = createPaste($_POST["paste"], (($_POST["desc"]) ? $_POST["desc"] : ""))){  //create
            msg("Paste created.<br><a href=\"pstbn.php?" . $pasteID . "\">View paste</a>");
        }
    }
}
else if($_SERVER["QUERY_STRING"]){  //check for query string
    viewPaste((int)$_SERVER["QUERY_STRING"]);   //display paste
}
else{
    msg("ERROR: No action specified.");
}

?>