Permission types

You can use any of the following permission types as input. You can also convert() between them.

octal

Permission type used by chmod.

Octal string where each digit represents a user class: user, group and others. Each digit's is a bitfield representing read, write and execute. Special permissions (setuid, setgid, sticky) can optionally be specified by prepending another digit.

An operator can be prepended:

• = (default): unset omitted permissions
• +: leave omitted permissions as is
• -: unset specified permissions

import { convert } from 'unix-permissions'

console.log(convert.stat('720')) // 'rwx-w----'
console.log(convert.stat('7000')) // '--S--S--T'
console.log(convert.stat('\\720')) // 'rwx-w----'
console.log(convert.stat('0720')) // 'rwx-w----'
console.log(convert.stat('0o720')) // 'rwx-w----'
console.log(convert.symbolic('+720')) // 'u+rwx,g+w'
console.log(convert.symbolic('-720')) // 'u-rwx,g-w'
console.log(convert.symbolic('=720')) // 'u=rwx,g=w,o='

number

Permission type used by Node.js fs.chmod().

It is the same as octal except:

• as a decimal number.
• no operator can be used.
• it can be used as input in JavaScript but not on the command line, where all numbers should be in octal form instead.

import { convert } from 'unix-permissions'

console.log(convert.stat(0)) // '---------'
console.log(convert.stat(1)) // '--------x'
console.log(convert.stat(3)) // '-------wx'
console.log(convert.stat(8)) // '-----x---'
console.log(convert.stat(512)) // '--------T'

stat

Permission type used by stat and ls.

It is a string where each character represents either the permission (r, w, x) or no permission (-). The special permission are indicated with S, s, T and t where lowercase implies x is also present.

Optionally a first character can be specified to indicate the file type (e.g. d for directories).

import { convert } from 'unix-permissions'

console.log(convert.octal('--------x')) // '0001'
console.log(convert.octal('--x--x--x')) // '0111'
console.log(convert.octal('--------T')) // '1000'
console.log(convert.octal('--------t')) // '1001'
console.log(convert.octal('d--------x')) // '0001'
console.log(convert.octal('--x --x --x')) // '0111'
console.log(convert.octal('rwx --- ---')) // '0700'
console.log(convert.octal('xwr --- ---')) // '0700'

symbolic

Permission type used by chmod as a string like gu+rx.

Starts with the user class (a for all, u for user, g for group, o for others) then the operator (+, - or =) and ends with the permissions characters.

While + leaves the omitted permissions as is, = unsets them. For example o=x is the same as combining o+x and o-rwt.

Several groups can be specified using a comma-separated list like g+x,o+r.

User classes can be concatenated like go+x.

import { convert } from 'unix-permissions'

console.log(convert.octal('o+wx')) // '+0003'
console.log(convert.octal('o=wx')) // '0003'
console.log(convert.octal('o-wx')) // '-0003'
console.log(convert.octal('go+x')) // '+0011'
console.log(convert.octal('g+x,o+x')) // '+0011'
console.log(convert.octal('a+x')) // '+0111'
console.log(convert.octal('+x')) // '+0111'
console.log(convert.octal('a+s')) // '+6000'
console.log(convert.octal('o+')) // '+0000'

object

Permission type as an object such as { user: { read: true, write: false } }.

The full syntax is:

{
  "user": { "read": true, "write": true, "execute": true },
  "group": { "read": true, "write": true, "execute": true },
  "others": { "read": true, "write": true, "execute": true },
  "special": { "setuid": true, "setgid": true, "sticky": true }
}

The values can be true, false or undefined. undefined leaves permissions as is while false unsets them.

import { convert } from 'unix-permissions'

console.log(convert.symbolic({ others: { read: true, execute: true } }))
// 'o+rx'

console.log(convert.symbolic({ others: { read: true, execute: false } }))
// 'o+r,o-x'

console.log(convert.symbolic({ others: { read: true, execute: undefined } }))
// 'o+r'

console.log(convert.symbolic({ all: { read: true } }))
// 'a+r'

console.log(convert.symbolic({}))
// 'a+'

console.log(
  convert.symbolic({ special: { setuid: true, setgid: true, sticky: true } }),
)
// 'ug+s,o+t'

On the command line:

unix-permissions convert.symbolic '{ "all": { "read": true } }' # a+r