tool::chmod-detail
chmod 664
rw-rw-r--
Group Editable File
Permission Structure
Owner (User)
✓Read (r)
✓Write (w)
✗Execute (x)
Group
✓Read (r)
✓Write (w)
✗Execute (x)
Others
✓Read (r)
✗Write (w)
✗Execute (x)
Octal
664Symbolic
rw-rw-r--Explanation
chmod 664 gives the owner and group members read and write permissions, while others get read-only. No execute bit makes this suitable for data files rather than scripts. Commonly used for team-shared source files, shared logs, and configuration files that group members need to edit.
Common Use Cases
- ▸Source code files edited collaboratively by a team
- ▸Log files shared across multiple services
- ▸Data files modified by group members (CSV, JSON)
- ▸Uploaded media files in web applications
- ▸Shared configuration files editable by a group
Security Considerations
664 is a safe permission for collaborative file access. The missing execute bit prevents uploaded files from being executed directly. In web upload directories, ensure files are group-writable but never grant execute (x). Use 640 or 600 for files containing sensitive data.
Command Examples
$ chmod 664 shared-config.json$ chmod 664 /var/log/app/access.log$ find /srv/project -type f -exec chmod 664 {} \;$ chmod 664 uploads/*.csvRelated Permissions
ad · 300×250
// related tools