Change mode or chmod selection detailed permission by selected users to read write or execute and octal digits expression

/scripts/Chmod_Selector.html 

Chmod Selector

Permissions	owner	group	other
read
write
execute
Permissions:
* CGI programs, 0755 * data files to be readable by CGI, 0644 * directories for data used by CGI, 0755 * data files to be writable by CGI, 0666 (data has absolutely no security) * directories for data used by CGI with write access, 0777 (no security) * CGI programs to run setuid, 4755 * data files for setuid CGI programs, 0600 or 0644 * directories for data used by setuid CGI programs, 0700 or 0755 * For a typical backend server process, 4750

Numeric mode:

From one to four octal digits Any omitted digits are assumed to be leading zeros.

1. The first digit = selects attributes for the set user ID (4) and set group ID (2) and save text image (1)S
2. The second digit = permissions for the user who owns the file: read (4), write (2), and execute (1)
3. The third digit = permissions for other users in the file's group: read (4), write (2), and execute (1)
4. The fourth digit = permissions for other users NOT in the file's group: read (4), write (2), and execute (1)

The octal (0-7) value is calculated by adding up the values for each digit

• User (rwx) = 4+2+1 = 7
• Group(rx) = 4+1 = 5
• World (rx) = 4+1 = 5
• chmode mode = 0755

Examples

• chmod 400 file - Read by owner
• chmod 040 file - Read by group
• chmod 004 file - Read by world
• chmod 200 file - Write by owner
• chmod 020 file - Write by group
• chmod 002 file - Write by world
• chmod 100 file - execute by owner
• chmod 010 file - execute by group
• chmod 001 file - execute by world

To combine these just add the numbers together:

• chmod 444 file - Allow read permission to owner and group and world
• chmod 777 file - Allow everyone to read, write, and execute file Permissions
• Of course, the permissions are the same letters that you see in the directory listing:
  • r Permission to read the file.
  • w Permission to write (or delete) the file.
  • x Permission to execute the file, or, in the case of a directory, search it.

Permissions

• u - User who owns the file.
• g - Group that owns the file.
• o - Other.
• a - All.
• r - Read the file.
• w - Write or edit the file.
• x - Execute or run the file as a program.

(Added: 9-Mar-2008 Rating: 0 Votes: 0) Rate It
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