Applications

Applications

ModuOS includes several built-in and userland applications.

Built-in Applications

Zenith4 Shell

The main shell interface for ModuOS.

Features:

• Command execution
• File operations
• Process management
• Drive mounting

Usage: Automatically started at boot

Real-Time Clock (rl-clock)

Display current date and time from RTC.

Command: clock

Userland Programs

cat.sqr

Display file contents to console.

Usage: cat <filename>

Example:

# cat /ModuOS/System64/pcname.txt
ModuOS-PC

echo.sqr

Print text to console.

Usage: echo <text>

Example:

# echo Hello, World!
Hello, World!

sh.sqr

Alternative shell implementation.

Usage: sh

memtest.sqr

Memory testing utility.

Usage: memtest

Tests:

• Memory allocation/deallocation
• Read/write verification
• Heap integrity

zsfetch.sqr

System information display (similar to neofetch).

Usage: zsfetch

Displays:

• OS name and version
• CPU model
• Memory usage
• Storage devices
• Uptime

Developing Applications

See also: SQR / SQRM / SQRL Formats

ELF Format

User programs must be in ELF64 format.

Compilation

cd userland
x86_64-elf-gcc -c program.c -o program.o
x86_64-elf-ld -T user.ld program.o -o program.sqr

Entry Point

void _start(void) {
    // Program entry point
    main();
    syscall_exit(0);
}

Next Steps

• Games - Built-in games
• Shell Commands - Shell usage
• System Calls - Programming interface