$ chmod 755 script.sh # Executable script — owner can edit, others can run chmod 644 config.conf # Config file — owner can edit, others read-only chmod 600 .ssh/id_rsa # Private key — owner only, no one else chmod 777 /tmp/shared # Fully open (use sparingly, never on production) chmod 700 ~/scripts/ # Private directory — owner only chmod 755 script.sh # Executable script — owner can edit, others can run chmod 644 config.conf # Config file — owner can edit, others read-only chmod 600 .ssh/id_rsa # Private key — owner only, no one else chmod 777 /tmp/shared # Fully open (use sparingly, never on production) chmod 700 ~/scripts/ # Private directory — owner only chmod 755 script.sh # Executable script — owner can edit, others can run chmod 644 config.conf # Config file — owner can edit, others read-only chmod 600 .ssh/id_rsa # Private key — owner only, no one else chmod 777 /tmp/shared # Fully open (use sparingly, never on production) chmod 700 ~/scripts/ # Private directory — owner only # Apply 755 to all directories, 644 to all files find /var/www/html -type d -exec chmod 755 {} \; find /var/www/html -type f -exec chmod 644 {} \; # Apply 755 to all directories, 644 to all files find /var/www/html -type d -exec chmod 755 {} \; find /var/www/html -type f -exec chmod 644 {} \; # Apply 755 to all directories, 644 to all files find /var/www/html -type d -exec chmod 755 {} \; find /var/www/html -type f -exec chmod 644 {} \; chmod -R 755 /var/www/html chmod -R 755 /var/www/html chmod -R 755 /var/www/html ls -la filename # Single file stat filename # Verbose output including octal ls -la /path/to/dir/ # Directory listing ls -la filename # Single file stat filename # Verbose output including octal ls -la /path/to/dir/ # Directory listing ls -la filename # Single file stat filename # Verbose output including octal ls -la /path/to/dir/ # Directory listing stat -c "%a" filename # Just the octal number stat -c "%a" filename # Just the octal number stat -c "%a" filename # Just the octal number - The chmod octal command (chmod 755 filename) - The symbolic command (chmod u=rwx,g=rx,o=rx filename) - A plain-English explanation of what those permissions mean - 7 = owner gets rwx (read + write + execute) - 5 = group gets r-x (read + execute, no write) - 5 = others get r-x