Perms is a chmod calculator — tick the read, write and execute boxes for owner, group and others, and it gives you the octal number (like 755) and the symbolic string (like rwxr-xr-x). Type a number and it ticks the boxes for you. Handy for setting file permissions on a server. Nothing is uploaded.

Read (4)

Write (2)

Execute (1)

Octal

Symbolic

rwxr-xr-x

Command

chmod 755 file

Each of the three roles — owner, group, others — gets a digit from 0 to 7, adding read (4), write (2) and execute (1). So 6 is read+write, 7 is all three. A leading fourth digit for setuid/setgid/sticky bits isn't shown here. Everything runs on your device.