Task 713: .SXP File Format

1. List of all the properties of this file format intrinsic to its file system

The .SXP file format refers to the S-expression (SXP) configuration file used primarily in Xen hypervisor environments (e.g., xend-config.sxp). It is a text-based format consisting of a sequence of S-expressions, which are Lisp-like parenthesized structures. Each top-level S-expression typically represents a key-value pair in the form (key value), where value can be a simple string, number, boolean, or nested list. The format has no fixed header or magic number; it is intrinsically a plain-text, human-readable configuration format parsed as nested lists.

The properties (configuration options) defined in the .SXP specification for Xen daemon configuration are:

• logfile: Path to the runtime log file (default: /var/log/xen/xend.log).
• loglevel: Logging threshold (possible values: DEBUG, INFO, WARNING, ERROR, CRITICAL; default: DEBUG).
• xend-http-server: Boolean to enable HTTP management server (default: no).
• xend-unix-server: Boolean to enable Unix domain socket server (default: yes).
• xend-relocation-server: Boolean to enable relocation server for migrations (default: no).
• xend-unix-path: Path to Unix domain socket (default: /var/lib/xend/xend-socket).
• xend-port: Port for HTTP server (default: 8000).
• xend-relocation-port: Port for relocation server (default: 8002).
• xend-address: Bind address for HTTP server (default: '' for all interfaces).
• xend-relocation-address: Bind address for relocation server (default: '' for all interfaces).
• console-limit: Per-domain console buffer limit in KB (default: 1024).
• network-script: Script for network setup (e.g., network-bridge or network-route).
• vif-script: Script for virtual interface setup (e.g., vif-bridge).
• dom0-min-mem: Minimum memory in MB reserved for Domain0 (default: 0, no auto-ballooning).
• dom0-cpus: Number of CPUs for Domain0 (default: 0, all available).
• enable-dump: Boolean to enable guest domain core dumps on crash (default: no).
• external-migration-tool: Tool for external device migration (e.g., /etc/xen/scripts/external-device-migrate).
• device-create-timeout: Timeout in seconds for device creation (default: 100).

These properties are not enforced by the file format itself but are intrinsic to Xen's use of .SXP. The format allows arbitrary key-value pairs, but these are the standard ones documented.

2. Two direct download links for files of format .SXP

• https://git.hipert.unimore.it/rtes/xen/-/raw/51373e7145540cfad3f262e135f4fe85a389310c/tools/examples/xend-config.sxp
• https://git.hipert.unimore.it/rtes/xen/-/raw/8b4c96f62222a7a4a61e0ab8c6171f968af7b665/tools/examples/xend-config.sxp

3. Ghost blog embedded html javascript that allows a user to drag n drop a file of format .SXP and it will dump to screen all these properties

This HTML/JS code can be embedded in a blog post. It parses the .SXP file as S-expressions, extracts properties (keys and values), and dumps them as JSON to the screen. Note: This is a basic parser assuming simple non-nested values; for nested, a more robust parser would be needed.

4. Python class that can open any file of format .SXP and decode read and write and print to console all the properties from the above list

import re
import json

class SXPParser:
    def __init__(self, filepath=None):
        self.properties = {}
        if filepath:
            self.read(filepath)

    def read(self, filepath):
        with open(filepath, 'r') as f:
            text = f.read()
        # Simple regex-based S-expression parser
        matches = re.findall(r'\(([^ )]+)\s+([^)]+)\)', text)
        for key, value in matches:
            self.properties[key] = value
        self.print_properties()

    def print_properties(self):
        print(json.dumps(self.properties, indent=4))

    def write(self, filepath):
        with open(filepath, 'w') as f:
            for key, value in self.properties.items():
                f.write(f'({key} {value})\n')

# Example usage:
# parser = SXPParser('example.sxp')
# parser.properties['new-key'] = 'new-value'
# parser.write('output.sxp')

This class reads the .SXP file, decodes it into a dict of properties, prints them to console as JSON, and can write back a new .SXP file from the dict.

5. Java class that can open any file of format .SXP and decode read and write and print to console all the properties from the above list

import java.io.*;
import java.util.*;
import java.util.regex.*;

public class SXPParser {
    private Map<String, String> properties = new HashMap<>();

    public SXPParser(String filepath) throws IOException {
        read(filepath);
    }

    public void read(String filepath) throws IOException {
        StringBuilder text = new StringBuilder();
        try (BufferedReader br = new BufferedReader(new FileReader(filepath))) {
            String line;
            while ((line = br.readLine()) != null) {
                text.append(line);
            }
        }
        // Simple regex-based S-expression parser
        Pattern pattern = Pattern.compile("\\(([^ )]+)\\s+([^)]+)\\)");
        Matcher matcher = pattern.matcher(text.toString());
        while (matcher.find()) {
            properties.put(matcher.group(1), matcher.group(2));
        }
        printProperties();
    }

    public void printProperties() {
        for (Map.Entry<String, String> entry : properties.entrySet()) {
            System.out.println(entry.getKey() + ": " + entry.getValue());
        }
    }

    public void write(String filepath) throws IOException {
        try (BufferedWriter bw = new BufferedWriter(new FileWriter(filepath))) {
            for (Map.Entry<String, String> entry : properties.entrySet()) {
                bw.write("(" + entry.getKey() + " " + entry.getValue() + ")\n");
            }
        }
    }

    // Example usage:
    // public static void main(String[] args) throws IOException {
    //     SXPParser parser = new SXPParser("example.sxp");
    //     parser.properties.put("new-key", "new-value");
    //     parser.write("output.sxp");
    // }
}

This Java class reads the .SXP file, decodes properties into a Map, prints them to console, and can write a new .SXP file.

6. Javascript class that can open any file of format .SXP and decode read and write and print to console all the properties from the above list

(Note: JavaScript runs in Node.js for file I/O; requires 'fs' module.)

const fs = require('fs');

class SXPParser {
    constructor(filepath) {
        this.properties = {};
        if (filepath) {
            this.read(filepath);
        }
    }

    read(filepath) {
        const text = fs.readFileSync(filepath, 'utf8');
        // Simple regex-based S-expression parser
        const matches = text.matchAll(/\(([^ )]+)\s+([^)]+)\)/g);
        for (const match of matches) {
            this.properties[match[1]] = match[2];
        }
        this.printProperties();
    }

    printProperties() {
        console.log(JSON.stringify(this.properties, null, 4));
    }

    write(filepath) {
        let content = '';
        for (const [key, value] of Object.entries(this.properties)) {
            content += `(${key} ${value})\n`;
        }
        fs.writeFileSync(filepath, content);
    }
}

// Example usage:
// const parser = new SXPParser('example.sxp');
// parser.properties['new-key'] = 'new-value';
// parser.write('output.sxp');

This JS class (for Node.js) reads the .SXP file, decodes to an object, prints to console as JSON, and writes a new .SXP file.

7. C class that can open any file of format .SXP and decode read and write and print to console all the properties from the above list

(Note: Using C++ for class support and simplicity; assumes simple non-nested values.)

#include <iostream>
#include <fstream>
#include <string>
#include <map>
#include <regex>

class SXPParser {
private:
    std::map<std::string, std::string> properties;

public:
    SXPParser(const std::string& filepath) {
        read(filepath);
    }

    void read(const std::string& filepath) {
        std::ifstream file(filepath);
        std::string text((std::istreambuf_iterator<char>(file)), std::istreambuf_iterator<char>());
        std::regex pattern(R"(\(([^ )]+)\s+([^)]+)\))");
        std::sregex_iterator iter(text.begin(), text.end(), pattern);
        std::sregex_iterator end;
        for (; iter != end; ++iter) {
            properties[(*iter)[1]] = (*iter)[2];
        }
        printProperties();
    }

    void printProperties() {
        for (const auto& pair : properties) {
            std::cout << pair.first << ": " << pair.second << std::endl;
        }
    }

    void write(const std::string& filepath) {
        std::ofstream file(filepath);
        for (const auto& pair : properties) {
            file << "(" << pair.first << " " << pair.second << ")\n";
        }
    }
};

// Example usage:
// int main() {
//     SXPParser parser("example.sxp");
//     parser.properties["new-key"] = "new-value";
//     parser.write("output.sxp");
//     return 0;
// }

This C++ class reads the .SXP file, decodes to a map, prints to console, and writes a new .SXP file.