.UPD

Task 751: .UPD File Format

Task 751: .UPD File format

thinkmelt@protonmail.com

Dec 14, 2025 • 6 min read

Specifications for the .UPD File Format

The .UPD file format is not a standardized binary format with a fixed internal structure. Based on comprehensive research, it is primarily associated with program update information files used by various applications. These files typically contain text-based data, such as update history, logs, or configuration details, and can be opened with a plain text editor. Examples include update files in software like VideoStudio (for scene information), PSpice (for property updates), or firmware updates in devices like car stereos or pinball displays. No universal specification exists for an internal binary or structured format, as usage varies by application. In many cases, .UPD files are ASCII text without predefined fields or headers.

List of Properties Intrinsic to the File System
The properties listed below are metadata attributes maintained by the file system (e.g., NTFS, ext4, or similar) for any file, including those with the .UPD extension. These are not specific to the internal content of .UPD files but are intrinsic to how the file system manages files:

File name
File size (in bytes)
Creation time
Last modification time
Last access time
File attributes (e.g., read-only, hidden, system, archive)
Owner (user ID or name)
Group (group ID or name)
Permissions (read, write, execute for owner, group, others)

Two Direct Download Links for .UPD Files

HTML/JavaScript for Drag-and-Drop .UPD File Dump
The following is a self-contained HTML document with embedded JavaScript that allows a user to drag and drop a .UPD file. Upon dropping, it displays the file system properties (metadata) accessible in a browser context, such as name, size, type, and last modified time. Note that browser security limits access to full file system metadata like owner or permissions; these are not available client-side.

UPD File Property Dumper

Drag and drop a .UPD file here

Python Class for Handling .UPD Files
The following Python class opens a .UPD file, reads its file system metadata properties, prints them to the console, and supports writing (modifying) certain properties like modification time. Reading the content is included for completeness, assuming text format, but decoding focuses on metadata as no binary structure exists.

import os
import stat
import time
from pathlib import Path

class UPDFileHandler:
    def __init__(self, filepath):
        self.filepath = Path(filepath)
        if not self.filepath.suffix.lower() == '.upd':
            raise ValueError("File must have .upd extension.")
        if not self.filepath.exists():
            raise FileNotFoundError(f"File {filepath} does not exist.")

    def read_properties(self):
        st = self.filepath.stat()
        properties = {
            'File name': self.filepath.name,
            'File size (bytes)': st.st_size,
            'Creation time': time.ctime(st.st_ctime),
            'Last modification time': time.ctime(st.st_mtime),
            'Last access time': time.ctime(st.st_atime),
            'File attributes': oct(st.st_mode),
            'Owner': os.getlogin(),  # Approximate; may vary by system
            'Group': 'N/A',  # Requires grp module for ID to name mapping
            'Permissions': stat.filemode(st.st_mode)
        }
        return properties

    def print_properties(self):
        props = self.read_properties()
        for key, value in props.items():
            print(f"{key}: {value}")

    def write_property(self, property_name, value):
        if property_name == 'Last modification time':
            os.utime(self.filepath, (self.filepath.stat().st_atime, value))
        else:
            raise NotImplementedError(f"Writing {property_name} not supported.")

    def read_content(self):
        with open(self.filepath, 'r') as f:
            return f.read()  # Assuming text format

# Example usage:
# handler = UPDFileHandler('example.upd')
# handler.print_properties()
# handler.write_property('Last modification time', time.time())

Java Class for Handling .UPD Files
The following Java class opens a .UPD file, reads its file system metadata properties, prints them to the console, and supports writing (modifying) certain properties like modification time.

import java.io.IOException;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.Paths;
import java.nio.file.attribute.BasicFileAttributes;
import java.nio.file.attribute.FileOwnerAttributeView;
import java.nio.file.attribute.FileTime;
import java.nio.file.attribute.PosixFileAttributes;
import java.nio.file.attribute.PosixFilePermissions;
import java.util.HashMap;
import java.util.Map;

public class UPDFileHandler {
    private final Path filepath;

    public UPDFileHandler(String filepathStr) throws IOException {
        this.filepath = Paths.get(filepathStr);
        if (!this.filepath.toString().toLowerCase().endsWith(".upd")) {
            throw new IllegalArgumentException("File must have .upd extension.");
        }
        if (!Files.exists(this.filepath)) {
            throw new IOException("File does not exist.");
        }
    }

    public Map<String, Object> readProperties() throws IOException {
        BasicFileAttributes attrs = Files.readAttributes(filepath, BasicFileAttributes.class);
        FileOwnerAttributeView ownerView = Files.getFileAttributeView(filepath, FileOwnerAttributeView.class);
        Map<String, Object> properties = new HashMap<>();
        properties.put("File name", filepath.getFileName().toString());
        properties.put("File size (bytes)", attrs.size());
        properties.put("Creation time", attrs.creationTime());
        properties.put("Last modification time", attrs.lastModifiedTime());
        properties.put("Last access time", attrs.lastAccessTime());
        properties.put("File attributes", attrs.isRegularFile() ? "Regular file" : "Other");
        properties.put("Owner", ownerView.getOwner().getName());
        try {
            PosixFileAttributes posixAttrs = Files.readAttributes(filepath, PosixFileAttributes.class);
            properties.put("Group", posixAttrs.group().getName());
            properties.put("Permissions", PosixFilePermissions.toString(posixAttrs.permissions()));
        } catch (UnsupportedOperationException e) {
            properties.put("Group", "N/A");
            properties.put("Permissions", "N/A");
        }
        return properties;
    }

    public void printProperties() throws IOException {
        Map<String, Object> props = readProperties();
        props.forEach((key, value) -> System.out.println(key + ": " + value));
    }

    public void writeProperty(String propertyName, Object value) throws IOException {
        if ("Last modification time".equals(propertyName) && value instanceof Long) {
            Files.setLastModifiedTime(filepath, FileTime.fromMillis((Long) value));
        } else {
            throw new UnsupportedOperationException("Writing " + propertyName + " not supported.");
        }
    }

    // Example usage:
    // public static void main(String[] args) throws IOException {
    //     UPDFileHandler handler = new UPDFileHandler("example.upd");
    //     handler.printProperties();
    //     handler.writeProperty("Last modification time", System.currentTimeMillis());
    // }
}

JavaScript Class for Handling .UPD Files
The following JavaScript class is for Node.js (using fs module) to open a .UPD file, read its metadata properties, print them to the console, and support writing certain properties. Browser contexts limit full access.

const fs = require('fs');
const path = require('path');

class UPDFileHandler {
    constructor(filepath) {
        this.filepath = filepath;
        if (!path.extname(this.filepath).toLowerCase() === '.upd') {
            throw new Error('File must have .upd extension.');
        }
        if (!fs.existsSync(this.filepath)) {
            throw new Error('File does not exist.');
        }
    }

    readProperties() {
        const stats = fs.statSync(this.filepath);
        return {
            'File name': path.basename(this.filepath),
            'File size (bytes)': stats.size,
            'Creation time': stats.birthtime.toISOString(),
            'Last modification time': stats.mtime.toISOString(),
            'Last access time': stats.atime.toISOString(),
            'File attributes': stats.mode.toString(8),
            'Owner': stats.uid,
            'Group': stats.gid,
            'Permissions': stats.mode.toString(8)
        };
    }

    printProperties() {
        const props = this.readProperties();
        for (const [key, value] of Object.entries(props)) {
            console.log(`${key}: ${value}`);
        }
    }

    writeProperty(propertyName, value) {
        if (propertyName === 'Last modification time') {
            fs.utimesSync(this.filepath, new Date(), new Date(value));
        } else {
            throw new Error(`Writing ${propertyName} not supported.`);
        }
    }
}

// Example usage:
// const handler = new UPDFileHandler('example.upd');
// handler.printProperties();
// handler.writeProperty('Last modification time', Date.now());

C Class for Handling .UPD Files
The following C code defines a struct acting as a class-like structure to open a .UPD file, read its metadata properties, print them to the console, and support writing certain properties like modification time.

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/stat.h>
#include <time.h>
#include <utime.h>
#include <pwd.h>
#include <grp.h>

typedef struct {
    char *filepath;
} UPDFileHandler;

UPDFileHandler* createUPDFileHandler(const char *filepath) {
    UPDFileHandler *handler = malloc(sizeof(UPDFileHandler));
    handler->filepath = strdup(filepath);
    const char *ext = strrchr(filepath, '.');
    if (!ext || strcasecmp(ext, ".upd") != 0) {
        fprintf(stderr, "File must have .upd extension.\n");
        free(handler->filepath);
        free(handler);
        return NULL;
    }
    struct stat st;
    if (stat(filepath, &st) != 0) {
        fprintf(stderr, "File does not exist.\n");
        free(handler->filepath);
        free(handler);
        return NULL;
    }
    return handler;
}

void destroyUPDFileHandler(UPDFileHandler *handler) {
    free(handler->filepath);
    free(handler);
}

void printProperties(UPDFileHandler *handler) {
    struct stat st;
    if (stat(handler->filepath, &st) != 0) {
        fprintf(stderr, "Error reading file stats.\n");
        return;
    }
    struct passwd *pwd = getpwuid(st.st_uid);
    struct group *grp = getgrgid(st.st_gid);
    char perm[10];
    snprintf(perm, 10, "%o", st.st_mode & 0777);

    printf("File name: %s\n", handler->filepath);
    printf("File size (bytes): %ld\n", st.st_size);
    printf("Creation time: %s", ctime(&st.st_ctime));
    printf("Last modification time: %s", ctime(&st.st_mtime));
    printf("Last access time: %s", ctime(&st.st_atime));
    printf("File attributes: %o\n", st.st_mode);
    printf("Owner: %s\n", pwd ? pwd->pw_name : "Unknown");
    printf("Group: %s\n", grp ? grp->gr_name : "Unknown");
    printf("Permissions: %s\n", perm);
}

int writeProperty(UPDFileHandler *handler, const char *propertyName, time_t value) {
    if (strcmp(propertyName, "Last modification time") == 0) {
        struct utimbuf ut;
        struct stat st;
        stat(handler->filepath, &st);
        ut.actime = st.st_atime;
        ut.modtime = value;
        return utime(handler->filepath, &ut);
    }
    fprintf(stderr, "Writing %s not supported.\n", propertyName);
    return -1;
}

// Example usage:
// int main() {
//     UPDFileHandler *handler = createUPDFileHandler("example.upd");
//     if (handler) {
//         printProperties(handler);
//         writeProperty(handler, "Last modification time", time(NULL));
//         destroyUPDFileHandler(handler);
//     }
//     return 0;
// }