Systems & DevOps
Chmod 755 Explained: Meaning, Permissions, and Examples
Mode 755 gives the owner read, write and execute permissions while group and others receive read and execute permissions.
Published
Permission matrix
755 = rwxr-xr-x
Owner
Read + write + execute
Group and others
Read + execute
What chmod 755 means
| Class | Digit | Permissions |
|---|---|---|
| Owner | 7 | read, write, execute |
| Group | 5 | read, execute |
| Others | 5 | read, execute |
How 4 + 2 + 1 becomes 7, 5 and 5
- Read = 4
- Write = 2
- Execute = 1
- 7 = 4 + 2 + 1; 5 = 4 + 1
Owner, group and others
The nine characters form three groups: owner rwx, group r-x, and others r-x.
rwxr-xr-x755 on files vs directories
For a regular file, execute allows running it when its format and environment permit. For a directory, execute controls traversal; read lists names and write changes directory entries.
755 vs 644 vs 777
| Mode | Symbolic | Typical distinction |
|---|---|---|
| 644 | rw-r--r-- | Writable by owner; not executable |
| 755 | rwxr-xr-x | Executable/traversable for everyone |
| 777 | rwxrwxrwx | Writable by everyone; rarely a safe fix |
chmod 755 vs chmod +x
755 replaces all three permission triplets with exact values. +x adds execute bits according to chmod semantics and the current mode; it does not necessarily produce 755.
Recursive chmod and common mistakes
- Applying the same mode recursively to files and directories.
- Ignoring ownership, ACLs, umask or mount options.
- Using 777 to hide an ownership problem.
- Copying a command with an unreviewed path.
Try the example
Translate 755 into symbolic permissions
Load the exact mode and inspect the owner, group and others matrix.
755Expected result: Octal 755 maps to rwxr-xr-x.
Try the example
Compare a non-executable 644 mode
See which execute bits distinguish 644 from 755.
644 → 755Expected result: Owner, group and others gain execute while existing read/write bits remain explained.
Calculate locally
Inspect permission 755
Use the permission matrix to compare octal, symbolic and command output without touching your filesystem.