chmod 550 — r-xr-x---

What chmod 550 allows, when to use it, and the calculator pre-filled with it — toggle any box to compare.

550
r-xr-x---
Owner5
r-x
Group5
r-x
Others0
---
Special bits
chmod 550 filename
chmod -R 550 /path/to/dir

What this means

Owner can read, execute. Group can read, execute. Others has no permissions.

What chmod 550 allows

WhoReadWriteExecute
Owner✓—✓
Group✓—✓
Others———

Owner and group can read and run, nobody can modify it — deployed application code that shouldn't change at runtime.

Commands

chmod 550 fileset it on one file or directory
chmod u=rx,g=rx,o= filethe same thing in symbolic form
chmod -R 550 dir/recursively — careful: it applies to files and directories alike
ls -l filecheck the result: -r-xr-x--- (a directory shows dr-xr-x---)

On a directory, read lets you list it, write lets you create and delete entries, and execute lets you enter it and open what's inside. That's why directories usually get 755 or 750 while files get 644 or 640.

Frequently asked

What does chmod 550 mean?

Owner: read, execute. Group: read, execute. Others: no access. In ls -l it shows as r-xr-x---.

What is the symbolic form of chmod 550?

chmod u=rx,g=rx,o= file — it sets exactly the same permissions as chmod 550.

← Chmod calculator

Common chmod permissions explained

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