Task 041: .ASM File Format
Task 041: .ASM File Format
File Format Specifications for .ASM
The .ASM file format is a plain text format used for assembly language source code. It stores low-level programming instructions that can be assembled into machine code using tools such as NASM, MASM, FASM, or GAS. The format is not binary but text-based, with a syntax that varies by assembler. It typically includes sections for data and code, directives for assembly control, labels for memory locations, instructions with mnemonics and operands, and comments. The structure is line-oriented, with no fixed header or magic number. Platform-specific variations exist, but the example syntax referenced here is x86-based, similar to NASM or MASM styles.
List of All the Properties of This File Format Intrinsic to Its File System
Based on the specifications, the intrinsic properties of the .ASM file format (focusing on its structure and content elements, as file system metadata like size and timestamps are general and not format-specific) are as follows:
- File Extension: .asm (primary); alternatives include .s or .S on Unix-like systems.
- MIME Type: text/plain.
- Encoding: Typically ASCII or UTF-8.
- Content Type: Plain text, editable in standard text editors.
- Structure: Line-based sequence of operations, organized into sections (e.g., .data for data definitions, .text for executable code).
- Sections: Defined using directives like "section .data" or ".text"; separate data, code, and other memory areas.
- Directives: Assembler commands such as "db" (define byte), "global", "extern", "section"; control assembly behavior and data declaration.
- Labels: Identifiers ending with a colon (e.g., "msg:"); mark locations in code or data.
- Mnemonics/Instructions: Operation codes like "mov", "push", "call"; specify actions with optional operands (registers, immediates, memory addresses).
- Operands: Arguments to instructions, including registers (e.g., eax), constants, or expressions.
- Comments: Lines or parts of lines starting with a semicolon (;); ignored by the assembler.
- Platform Specificity: Syntax and available mnemonics depend on architecture (e.g., x86, ARM) and assembler.
- Preprocessor Support: In .S files, may include directives like #define or #include.
Two Direct Download Links for Files of Format .ASM
- https://raw.githubusercontent.com/JaoCR/asm-examples/master/hello/hello.asm (Example: Simple "Hello World" program in assembly).
- https://raw.githubusercontent.com/JaoCR/asm-examples/master/file/file.asm (Example: File handling operations in assembly).
Ghost Blog Embedded HTML JavaScript for Drag-and-Drop .ASM File Dump
The following is an embeddable HTML snippet with JavaScript for a Ghost blog (or similar). It creates a drop zone where users can drag and drop a .ASM file. The script reads the file as text, parses it to extract the properties (sections, directives, labels, instructions, comments), and dumps them to the screen in a formatted output area.
Python Class for .ASM File Handling
The following Python class opens a .ASM file, reads its content, decodes (parses) it to extract properties, prints them to the console, and allows writing the content back to a file.
import os
class AsmFile:
def __init__(self, filepath):
self.filepath = filepath
self.content = None
self.properties = {
'sections': [],
'directives': [],
'labels': [],
'instructions': [],
'comments': []
}
def read(self):
with open(self.filepath, 'r', encoding='utf-8') as f:
self.content = f.readlines()
self.decode()
def decode(self):
for line in self.content:
line = line.strip()
if not line:
continue
if line.startswith(';'):
self.properties['comments'].append(line)
elif line.startswith('section ') or line.startswith('.'):
self.properties['sections'].append(line)
elif line.endswith(':'):
self.properties['labels'].append(line[:-1])
elif line.startswith('db ') or line.startswith('global ') or line.startswith('extern '):
self.properties['directives'].append(line)
else:
mnemonic = line.split()[0].lower() if ' ' in line else line.lower()
if mnemonic in ['mov', 'push', 'call', 'add', 'sub']: # Example mnemonics
self.properties['instructions'].append(line)
def print_properties(self):
for key, values in self.properties.items():
print(f"{key.upper()}:")
for value in values:
print(value)
print()
def write(self, new_filepath=None):
if new_filepath is None:
new_filepath = self.filepath
with open(new_filepath, 'w', encoding='utf-8') as f:
f.write(''.join(self.content))
Java Class for .ASM File Handling
The following Java class opens a .ASM file, reads its content, decodes (parses) it to extract properties, prints them to the console, and allows writing the content back to a file.
import java.io.*;
import java.util.*;
public class AsmFile {
private String filepath;
private List<String> content;
private Map<String, List<String>> properties;
public AsmFile(String filepath) {
this.filepath = filepath;
this.content = new ArrayList<>();
this.properties = new HashMap<>();
properties.put("sections", new ArrayList<>());
properties.put("directives", new ArrayList<>());
properties.put("labels", new ArrayList<>());
properties.put("instructions", new ArrayList<>());
properties.put("comments", new ArrayList<>());
}
public void read() throws IOException {
try (BufferedReader reader = new BufferedReader(new FileReader(filepath))) {
String line;
while ((line = reader.readLine()) != null) {
content.add(line + "\n");
}
}
decode();
}
private void decode() {
for (String line : content) {
String trimmed = line.trim();
if (trimmed.isEmpty()) continue;
if (trimmed.startsWith(";")) {
properties.get("comments").add(trimmed);
} else if (trimmed.startsWith("section ") || trimmed.startsWith(".")) {
properties.get("sections").add(trimmed);
} else if (trimmed.endsWith(":")) {
properties.get("labels").add(trimmed.substring(0, trimmed.length() - 1));
} else if (trimmed.startsWith("db ") || trimmed.startsWith("global ") || trimmed.startsWith("extern ")) {
properties.get("directives").add(trimmed);
} else {
String mnemonic = trimmed.split(" ")[0].toLowerCase();
if (Arrays.asList("mov", "push", "call", "add", "sub").contains(mnemonic)) { // Example mnemonics
properties.get("instructions").add(trimmed);
}
}
}
}
public void printProperties() {
for (Map.Entry<String, List<String>> entry : properties.entrySet()) {
System.out.println(entry.getKey().toUpperCase() + ":");
for (String value : entry.getValue()) {
System.out.println(value);
}
System.out.println();
}
}
public void write(String newFilepath) throws IOException {
if (newFilepath == null) {
newFilepath = filepath;
}
try (BufferedWriter writer = new BufferedWriter(new FileWriter(newFilepath))) {
for (String line : content) {
writer.write(line);
}
}
}
}
JavaScript Class for .ASM File Handling
The following JavaScript class (assuming Node.js environment for file I/O) opens a .ASM file, reads its content, decodes (parses) it to extract properties, prints them to the console, and allows writing the content back to a file.
const fs = require('fs');
class AsmFile {
constructor(filepath) {
this.filepath = filepath;
this.content = null;
this.properties = {
sections: [],
directives: [],
labels: [],
instructions: [],
comments: []
};
}
read() {
this.content = fs.readFileSync(this.filepath, 'utf8').split('\n');
this.decode();
}
decode() {
this.content.forEach(line => {
line = line.trim();
if (!line) return;
if (line.startsWith(';')) {
this.properties.comments.push(line);
} else if (line.startsWith('section ') || line.startsWith('.')) {
this.properties.sections.push(line);
} else if (line.endsWith(':')) {
this.properties.labels.push(line.slice(0, -1));
} else if (line.startsWith('db ') || line.startsWith('global ') || line.startsWith('extern ')) {
this.properties.directives.push(line);
} else {
const mnemonic = line.split(' ')[0].toLowerCase();
if (['mov', 'push', 'call', 'add', 'sub'].includes(mnemonic)) { // Example mnemonics
this.properties.instructions.push(line);
}
}
});
}
printProperties() {
for (const [key, values] of Object.entries(this.properties)) {
console.log(`${key.toUpperCase()}:`);
values.forEach(value => console.log(value));
console.log('');
}
}
write(newFilepath = null) {
if (!newFilepath) newFilepath = this.filepath;
fs.writeFileSync(newFilepath, this.content.join('\n'), 'utf8');
}
}
C++ Class for .ASM File Handling
The following C++ class opens a .ASM file, reads its content, decodes (parses) it to extract properties, prints them to the console, and allows writing the content back to a file.
#include <iostream>
#include <fstream>
#include <vector>
#include <map>
#include <string>
#include <algorithm>
class AsmFile {
private:
std::string filepath;
std::vector<std::string> content;
std::map<std::string, std::vector<std::string>> properties;
public:
AsmFile(std::string fp) : filepath(fp) {
properties["sections"] = {};
properties["directives"] = {};
properties["labels"] = {};
properties["instructions"] = {};
properties["comments"] = {};
}
void read() {
std::ifstream file(filepath);
if (!file.is_open()) {
std::cerr << "Error opening file." << std::endl;
return;
}
std::string line;
while (std::getline(file, line)) {
content.push_back(line + "\n");
}
file.close();
decode();
}
void decode() {
std::vector<std::string> mnemonics = {"mov", "push", "call", "add", "sub"}; // Example mnemonics
for (auto& line : content) {
std::string trimmed = line;
trimmed.erase(0, trimmed.find_first_not_of(" \t"));
trimmed.erase(trimmed.find_last_not_of(" \t") + 1);
if (trimmed.empty()) continue;
if (trimmed[0] == ';') {
properties["comments"].push_back(trimmed);
} else if (trimmed.substr(0, 8) == "section " || trimmed[0] == '.') {
properties["sections"].push_back(trimmed);
} else if (trimmed.back() == ':') {
trimmed.pop_back();
properties["labels"].push_back(trimmed);
} else if (trimmed.substr(0, 3) == "db " || trimmed.substr(0, 7) == "global " || trimmed.substr(0, 7) == "extern ") {
properties["directives"].push_back(trimmed);
} else {
size_t spacePos = trimmed.find(' ');
std::string mnemonic = (spacePos != std::string::npos) ? trimmed.substr(0, spacePos) : trimmed;
std::transform(mnemonic.begin(), mnemonic.end(), mnemonic.begin(), ::tolower);
if (std::find(mnemonics.begin(), mnemonics.end(), mnemonic) != mnemonics.end()) {
properties["instructions"].push_back(trimmed);
}
}
}
}
void printProperties() {
for (const auto& pair : properties) {
std::cout << pair.first << ":" << std::endl;
for (const auto& value : pair.second) {
std::cout << value << std::endl;
}
std::cout << std::endl;
}
}
void write(std::string newFilepath = "") {
if (newFilepath.empty()) newFilepath = filepath;
std::ofstream file(newFilepath);
if (!file.is_open()) {
std::cerr << "Error writing file." << std::endl;
return;
}
for (const auto& line : content) {
file << line;
}
file.close();
}
};