Chmod Explainer Tool
<p>Convert numeric chmod permissions (e.g., 755) to symbolic notation (e.g., rwxr-xr-x) and vice versa. Understand Linux file permissions with detailed explanations.</p>
Chmod Permission Converter
🔢Numeric to Symbolic
🔤Symbolic to Numeric
📚Understanding Chmod Permissions
User (Owner)
File owner's permissions
Group
Group members' permissions
Others
Everyone else's permissions
Permission Characters:
- r = Read permission
- w = Write permission
- x = Execute permission
- - = No permission
Numeric Values:
- 4 = Read (r)
- 2 = Write (w)
- 1 = Execute (x)
- 0 = No permission (-)
💡Common Permission Examples
Directory permissions (common for web folders)
File permissions (readable by all, writable by owner)
Full permissions (use with caution!)
Owner only (common for private files)
Owner and group (common for scripts)
Read-only (common for config files)
⚠️Security Best Practices
❌ Avoid These:
- • Using 777 permissions (too permissive)
- • Giving write access to others (666)
- • Making sensitive files world-readable
- • Using 000 permissions (can cause issues)
✅ Recommended:
- • 755 for directories (rwxr-xr-x)
- • 644 for regular files (rw-r--r--)
- • 600 for private files (rw-------)
- • 750 for group-shared content (rwxr-x---)
What is chmod?
chmod (change mode) is a command-line utility in Unix and Linux systems used to change the access permissions of files and directories. Permissions control who can read, write, or execute a file.
Understanding File Permissions
File permissions in Linux are represented in two ways:
- Symbolic notation: Uses letters like rwxr-xr-x
- Numeric notation: Uses octal numbers like 755
Both notations represent the same permissions for three categories: Owner, Group, and Others.
Permission Categories
- Owner: The user who owns the file has full control over permissions
- Group: Users in the same group as the file
- Others: All other users on the system
Common Use Cases
Directories
Use 755 (rwxr-xr-x) for directories that need to be accessible by others
Scripts
Use 755 (rwxr-xr-x) for executable scripts
Config Files
Use 644 (rw-r--r--) for configuration files
Private Files
Use 600 (rw-------) for sensitive files
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