Changing directories in the background

[James Cameron]

>>>>> On 30 Apr 91 05:52:42 GMT, gheim at eng.auburn.edu (Greg Heim) said:
Greg> Nntp-Posting-Host: lab14.eng.auburn.edu

Greg> Howdy,

Greg> I just tried the following:

Greg>    cd /new/dir &

Greg> by accident and my directory didn't change.  Can anybody tell me what happens
Greg> internally here?


Greg> Thanks in advance,

Greg> Greg



Well, to put it simply the & creates a child of the original, inherenting
the parents stuff, but not causing anything to happen to the parent.

Graphically, looks something like this:

____________________________________________________________________
|                                                                  |
|     Parent - (shell in this case)  certain commands work on this |
|              while others cause it to bear children (another     |
|              call for sex safe!)                                 |
___________________________________________________________________
         |                   |                     |
         |                   |                     |
         |                   |                     |
         |                   |                     |
   ----------------   ---------------    --------------------
   | shell scripts|   |  background |    |  Those programs  |
   ----------------   |     jobs    |    |  which do exec   |
               /\     ---------------    |      calls       |
                \\          /\           --------------------
                 \\         ||           /|
                  \\        ||          //
                   \\       ||         //
                    \\      ||        //
                     \\     ||       //
                      \\    ||      //

                         Children

Now, I am sure that others with have something to say about
this, but that is what I know....*8-)

jc
--
					-- James Cameron  (jc at raven.bu.edu)

Signal Processing and Interpretation Lab.  Boston, Mass  (617) 353-2879
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