GUIDE
Read and change Unix file permissions
Work out who can read, write or execute a file before choosing permission digits.
On this page
Read the three digits
The digits refer to owner, group and everyone else, in that order. Read adds 4, write adds 2 and execute adds 1.
644 = rw-r--r--. The owner can read and write; the other two groups can only read.Add execute for one group
In Chmod Calculator select Example file, then check Owner Execute. The other two digits stay the same.
644 → 744. Only the owner gains execute permission.Understand directory access
On directories, execute allows traversal. Applying file permissions to a directory can therefore have a different effect. This calculator covers ordinary permissions and does not apply changes to your files.
755 on a directory gives the owner read/write/traverse and the other groups read/traverse.