Linux File Permissions Explained: How to Use chmod for Beginners

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Linux file permissions control access to files and directories through three levels — owner, group, and others — each with read, write, and execute rights. The chmod command lets users modify these permissions using either symbolic notation (e.g., g+rx) or octal notation (e.g., 755). Related commands like chown handle file ownership changes, while umask defines default permission settings for newly created files. Linux also supports special permission bits — setuid, setgid, and sticky bit — which govern execution privileges, group inheritance, and file deletion restrictions respectively. Together, these tools form the foundation of access control and security management on Linux systems.

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ProgrammingDEV Community ·

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