Task 502: .P File Format
Task 502: .P File Format
File Format Specifications for the .P File Format
The .P file extension is associated with several formats, but the most common and well-documented one is Pascal source code files, used for programs written in the Pascal programming language. Pascal is a procedural language originally designed by Niklaus Wirth in 1970. The file contains plain text source code that follows Pascal syntax and can be compiled into executables using compilers like Free Pascal or Turbo Pascal. The format is ASCII or UTF-8 text, with no binary structure or header—it's simply the code itself. The specifications are defined in the ISO/IEC 7185 standard for Standard Pascal, with extensions in ISO 10206 for Extended Pascal. For more details, see the Free Pascal documentation at https://www.freepascal.org/docs.html or Wirth's original report.
Other possible .P formats include Python pickle files (binary serialization), MATLAB P-code (proprietary obfuscated code), or LightWave plug-ins (binary plugins), but Pascal is the most traditional text-based use. Since the task refers to "the .P file format" and involves decoding/reading/writing in multiple languages, I'll assume it's the Pascal source code format, as it's open and straightforward for implementation. If it's intended as a binary format like pickle, note that pickle has public protocol details in Python's documentation, but its "properties" would involve opcodes and serialization structures.
- List of all the properties of this file format intrinsic to its file system.
Since .P for Pascal is a plain text format, its "intrinsic" properties are the standard file system metadata associated with any file on disk (e.g., not part of the content but managed by the OS file system like ext4, NTFS, or APFS). These include:
- File size (in bytes)
- Creation time (birth time, if supported)
- Modification time
- Access time
- Permissions (read/write/execute bits for owner, group, others; or equivalent ACLs)
- Owner user ID (UID)
- Group ID (GID)
- File type (e.g., regular file)
- Inode number (on Unix-like systems)
- Number of hard links
These are common across file systems, though some (like inode) are OS-specific. For cross-platform consistency, the codes below focus on widely available ones like size, times, and permissions.
- Two direct download links for files of format .P.
- https://raw.githubusercontent.com/yala/MLCodeLab/master/lab1/data/beer/overall_dev.p
- https://raw.githubusercontent.com/yala/MLCodeLab/master/lab1/data/beer/overall_test.p
These are example .p files from a machine learning dataset repository (text-based data files, likely compatible with Pascal or general text parsing).
- Ghost blog embedded HTML JavaScript for drag-n-drop to dump properties.
Here's a self-contained HTML snippet with embedded JavaScript that can be embedded in a Ghost blog post. It creates a drop zone where the user can drag a .P file. Upon drop, it checks the extension, reads the file metadata (using the browser's File API), and dumps the properties to the screen (name, size, type, lastModified). Note: Browser security limits access to full file system metadata like UID/GID/permissions; only basic properties are available.
- Python class for opening, decoding/reading/writing, and printing properties.
Here's a Python class that opens a .P file (assuming text for Pascal), reads the file system properties using os.stat, prints them to console, and includes a method to write a new .P file with sample content.
import os
import time
class PFileHandler:
def __init__(self, filepath):
if not filepath.lower().endswith('.p'):
raise ValueError("File must have .p extension")
self.filepath = filepath
def read_properties(self):
stat = os.stat(self.filepath)
properties = {
'File size': f"{stat.st_size} bytes",
'Creation time': time.ctime(stat.st_ctime),
'Modification time': time.ctime(stat.st_mtime),
'Access time': time.ctime(stat.st_atime),
'Permissions': oct(stat.st_mode)[-3:], # e.g., '755'
'Owner UID': stat.st_uid,
'Group GID': stat.st_gid,
'Inode number': stat.st_ino,
'Number of hard links': stat.st_nlink,
}
return properties
def print_properties(self):
props = self.read_properties()
print("Properties of", self.filepath)
for key, value in props.items():
print(f"{key}: {value}")
def write_file(self, content="(* Sample Pascal code *)\nBEGIN\n Writeln('Hello, World!');\nEND."):
with open(self.filepath, 'w') as f:
f.write(content)
print(f"Written to {self.filepath}")
# Example usage:
# handler = PFileHandler('example.p')
# handler.print_properties()
# handler.write_file()
- Java class for opening, decoding/reading/writing, and printing properties.
Here's a Java class using java.nio.file to get attributes. It opens a .P file, reads properties, prints to console, and includes a write method.
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.PosixFileAttributes;
import java.nio.file.attribute.PosixFilePermissions;
import java.util.Date;
public class PFileHandler {
private final Path path;
public PFileHandler(String filepath) {
this.path = Paths.get(filepath);
if (!filepath.toLowerCase().endsWith(".p")) {
throw new IllegalArgumentException("File must have .p extension");
}
}
public void printProperties() throws IOException {
BasicFileAttributes attrs = Files.readAttributes(path, BasicFileAttributes.class);
System.out.println("Properties of " + path);
System.out.println("File size: " + attrs.size() + " bytes");
System.out.println("Creation time: " + new Date(attrs.creationTime().toMillis()));
System.out.println("Modification time: " + new Date(attrs.lastModifiedTime().toMillis()));
System.out.println("Access time: " + new Date(attrs.lastAccessTime().toMillis()));
System.out.println("File type: " + (attrs.isRegularFile() ? "Regular file" : "Other"));
if (Files.getFileStore(path).supportsFileAttributeView("posix")) {
PosixFileAttributes posixAttrs = Files.readAttributes(path, PosixFileAttributes.class);
System.out.println("Permissions: " + PosixFilePermissions.toString(posixAttrs.permissions()));
System.out.println("Owner: " + posixAttrs.owner().getName());
System.out.println("Group: " + posixAttrs.group().getName());
}
}
public void writeFile(String content) throws IOException {
if (content == null) {
content = "(* Sample Pascal code *)\nBEGIN\n Writeln('Hello, World!');\nEND.";
}
Files.writeString(path, content);
System.out.println("Written to " + path);
}
// Example usage:
// public static void main(String[] args) throws IOException {
// PFileHandler handler = new PFileHandler("example.p");
// handler.printProperties();
// handler.writeFile(null);
// }
}
- JavaScript class for opening, decoding/reading/writing, and printing properties.
Here's a JavaScript class (for Node.js, as browser JS can't access full file system metadata). It uses fs to get stats, prints to console, and includes a write method. For browser, see the drag-n-drop in #3.
const fs = require('fs');
const path = require('path');
class PFileHandler {
constructor(filepath) {
if (!filepath.toLowerCase().endsWith('.p')) {
throw new Error('File must have .p extension');
}
this.filepath = filepath;
}
readProperties() {
const stat = fs.statSync(this.filepath);
return {
'File size': `${stat.size} bytes`,
'Creation time': stat.birthtime.toString(),
'Modification time': stat.mtime.toString(),
'Access time': stat.atime.toString(),
'Permissions': (stat.mode & 0o777).toString(8), // e.g., '755'
'Owner UID': stat.uid,
'Group GID': stat.gid,
'Inode number': stat.ino,
'Number of hard links': stat.nlink,
};
}
printProperties() {
const props = this.readProperties();
console.log(`Properties of ${this.filepath}`);
for (const [key, value] of Object.entries(props)) {
console.log(`${key}: ${value}`);
}
}
writeFile(content = '(* Sample Pascal code *)\nBEGIN\n Writeln(\'Hello, World!\');\nEND.') {
fs.writeFileSync(this.filepath, content);
console.log(`Written to ${this.filepath}`);
}
}
// Example usage:
// const handler = new PFileHandler('example.p');
// handler.printProperties();
// handler.writeFile();
- C class for opening, decoding/reading/writing, and printing properties.
Since C doesn't have classes, here's a struct with functions (C-style "class"). Uses stat to get properties, prints to stdout, and includes a write function.
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/stat.h>
#include <time.h>
#include <fcntl.h>
#include <unistd.h>
typedef struct {
char *filepath;
} PFileHandler;
PFileHandler* createPFileHandler(const char *filepath) {
if (strstr(filepath, ".p") == NULL && strstr(filepath, ".P") == NULL) {
fprintf(stderr, "File must have .p extension\n");
exit(1);
}
PFileHandler *handler = malloc(sizeof(PFileHandler));
handler->filepath = strdup(filepath);
return handler;
}
void destroyPFileHandler(PFileHandler *handler) {
free(handler->filepath);
free(handler);
}
void printProperties(PFileHandler *handler) {
struct stat st;
if (stat(handler->filepath, &st) != 0) {
perror("stat");
return;
}
printf("Properties of %s\n", handler->filepath);
printf("File size: %ld bytes\n", st.st_size);
printf("Creation time: %s", ctime(&st.st_ctime));
printf("Modification time: %s", ctime(&st.st_mtime));
printf("Access time: %s", ctime(&st.st_atime));
printf("Permissions: %o\n", st.st_mode & 0777);
printf("Owner UID: %d\n", st.st_uid);
printf("Group GID: %d\n", st.st_gid);
printf("Inode number: %ld\n", st.st_ino);
printf("Number of hard links: %ld\n", st.st_nlink);
}
void writeFile(PFileHandler *handler, const char *content) {
if (content == NULL) {
content = "(* Sample Pascal code *)\nBEGIN\n Writeln('Hello, World!');\nEND.";
}
FILE *f = fopen(handler->filepath, "w");
if (f == NULL) {
perror("fopen");
return;
}
fprintf(f, "%s", content);
fclose(f);
printf("Written to %s\n", handler->filepath);
}
// Example usage:
// int main() {
// PFileHandler *handler = createPFileHandler("example.p");
// printProperties(handler);
// writeFile(handler, NULL);
// destroyPFileHandler(handler);
// return 0;
// }