CertiGuide to A+ (A+ 4 Real)  9  Chapter 7: History, Installing and Use of the MacOS       9  Using the UNIX Terminal

Using the UNIX Terminal 1 Other Commands

ls is used to list files and directories. There are options that are more extensive available. They can be found by typing “man ls” and reading the manual page

In addition, it helps to know what you are seeing by using ls, so here is the each files and folders identifier.

Following the file name, there are three characters, identifying owner privileges, group privileges and other privileges.

1. If r, the file is readable; if -, it is not readable.
   
   
2. If w, the file is writable; if -, it is not writable.
   
   
3. The first of the following that applies:
   • S If in the owner permissions, the file is not executable and set-user-ID mode is set. If in the group permissions, the file is not executable and set-group-ID mode is set.
     
     
   • s If in the owner permissions, the file is executable and set-user-ID mode is set. If in the group permissions, the file is executable and set-group-ID mode is set.
     
     
   • x The file is executable or the directory is searchable, but cannot be altered.
     
     
   • - The file is neither readable, writable, executable, nor set-user-ID nor set-group-ID mode, nor sticky. (See below.)

These next two apply only to the third character in the last group (other permissions).

• T The sticky bit is set (mode 1000), but not execute or search permission. (See chmod(1) or sticky(8).)
  
  
• t The sticky bit is set (mode 1000), and is searchable or executable. (See chmod(1) or sticky(8).)

Modes may be absolute or symbolic. An absolute mode is an octal number constructed by or using the following values:

• 4000 set-user-ID-on-execution
  
  
• 2000 set-group-ID-on-execution
  
  
• 1000 sticky bit, see chmod(2)
  
  
• 0400 read by owner
  
  
• 0200 write by owner
  
  
• 0100 execute (or search for directories) by owner
  
  
• 0070 read, write, execute/search by group
  
  
• 0007 read, write, execute/search by others

The read, write, and execute/search values for group and others are encoded as described for owner.

Using the UNIX Terminal 1 Other Commands