os

The os module provides Node.js-compatible operating system information APIs for JSH applications.

arch()

Returns CPU architecture.

Syntax

arch()

Usage example

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const os = require('os');
console.println(os.arch());

platform()

Returns platform name such as darwin, linux, or windows.

Syntax

platform()

type()

Returns OS type such as Darwin, Linux, or Windows_NT.

Syntax

type()

release()

Returns kernel release/version string.

Syntax

release()

hostname()

Returns host name.

Syntax

hostname()

homedir()

Returns current user home directory.

Syntax

homedir()

tmpdir()

Returns the default temporary directory path.

Syntax

tmpdir()

endianness()

Returns CPU endianness: BE or LE.

Syntax

endianness()

EOL

Platform-specific end-of-line marker.

• POSIX: \n
• Windows: \r\n

Usage example

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const os = require('os');
console.println(JSON.stringify(os.EOL));

totalmem(), freemem()

Returns total/free memory in bytes.

Syntax

totalmem()
freemem()

Usage example

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const os = require('os');
console.println('total:', os.totalmem());
console.println('free :', os.freemem());

uptime()

Returns system uptime in seconds.

Syntax

uptime()

bootTime()

Returns system boot time as Unix timestamp.

Syntax

bootTime()

loadavg()

Returns load averages as [1min, 5min, 15min].

Syntax

loadavg()

cpus()

Returns per-CPU information array.

Each item includes fields like:

• model, speed, cores
• vendor, family, model, stepping
• times.user, times.nice, times.sys, times.idle, times.irq (milliseconds)

Syntax

cpus()

Usage example

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const os = require('os');
const list = os.cpus();
console.println(Array.isArray(list), list.length > 0);

cpuCounts()

Returns CPU count.

• true: logical CPU count
• false: physical CPU count

Syntax

cpuCounts(logical)

cpuPercent()

Returns CPU usage percentages.

• intervalSec: sampling interval in seconds (0 for immediate)
• perCPU: return per-core values when true

Syntax

cpuPercent(intervalSec, perCPU)

Usage example

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const os = require('os');
console.println(Array.isArray(os.cpuPercent(0, true)));

networkInterfaces()

Returns network interface information object.

The object shape is:

• key: interface name
• value: array of address objects
  • address
  • family (IPv4/IPv6)
  • internal (boolean)

Syntax

networkInterfaces()

hostInfo()

Returns host information object.

Common fields include:

• hostname, uptime, bootTime, procs
• os, platform, platformFamily, platformVersion
• kernelVersion, kernelArch
• virtualizationSystem, virtualizationRole, hostId

Syntax

hostInfo()

userInfo()

Returns current user information.

Returned fields include:

• username, homedir, shell
• uid, gid

Syntax

userInfo([options])

diskPartitions()

Returns disk partition list.

Syntax

diskPartitions([all])

Usage example

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const os = require('os');
const parts = os.diskPartitions();
console.println(Array.isArray(parts), parts.length >= 0);

diskUsage()

Returns disk usage for the given path.

Typical fields include total, used, free, usedPercent.

Syntax

diskUsage(path)

diskIOCounters()

Returns disk I/O counters.

• names omitted or empty: all devices
• names specified: selected devices

Syntax

diskIOCounters([names])

netProtoCounters()

Returns network protocol counters.

Syntax

netProtoCounters([proto])

constants

OS constants object.

Main fields

• constants.signals
  • SIGHUP, SIGINT, SIGQUIT, SIGILL, SIGTRAP, SIGABRT, SIGBUS, SIGFPE, SIGKILL, SIGUSR1, SIGSEGV, SIGUSR2, SIGPIPE, SIGALRM, SIGTERM
• constants.priority
  • PRIORITY_LOW, PRIORITY_BELOW_NORMAL, PRIORITY_NORMAL, PRIORITY_ABOVE_NORMAL, PRIORITY_HIGH, PRIORITY_HIGHEST

Usage example

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const os = require('os');
console.println(os.constants.signals.SIGINT);
console.println(os.constants.priority.PRIORITY_NORMAL);