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Re: Bash commands



On Wed, 2005-10-19 at 14:44 +0100, michael wrote:
> On Wed, 2005-10-19 at 05:01 -0700, Freddy Freeloader wrote:
> > michael wrote:
> > 
> > >On Tue, 2005-10-18 at 15:49 -0700, Freddy Freeloader wrote:
> > >  
> > >
> > >>Thanks for answering.  Sorry it's taken so long to answer.  I've just 
> > >>been too busy to get back to this.  I've inserted my comments in line. 
> > >>
> > >>michael wrote:
> > >>
> > >>    
> > >>
> > >>>On Thu, 2005-10-13 at 08:18 -0700, Freddy Freeloader wrote:
> > >>> 
> > >>>
> > >>>      
> > >>>
> > >>>>Hi all,
> > >>>>
> > >>>>I downloaded the Advanced Bash Scripting Guide the other day an have 
> > >>>>started to work my way through it.  I'm fairly new to bash so I get more 
> > >>>>than a little confused when the output I get is nothing similar to what 
> > >>>>the ABS Guide says it should be. 
> > >>>>
> > >>>>Here is what has me confused at the moment.
> > >>>>
> > >>>>b=${a/23/BB}
> > >>>>
> > >>>>echo "b = $b"
> > >>>>
> > >>>>Now the ABS guide says that where I'm setting b it should be 
> > >>>>substituting BB for 23.  It also says that the output of 'echo "b - $b"' 
> > >>>>should be: b = BB35
> > >>>>
> > >>>>However, what I get as output is as follows:
> > >>>>
> > >>>>ffreeloader@Job:~$ echo "b = $b"
> > >>>>b = 
> > >>>>   
> > >>>>
> > >>>>        
> > >>>>
> > >>>if a is unset then that is correct...
> > >>>      
> > >>>
> > >
> > >
> > >i take it you're agreeing with me that it is printing what you expect 
> > >
> > >  
> > >
> > Actually I have no idea why it is printing what it does.  If I knew I 
> > wouldn't be here asking about this.   As I said before it doesn't 
> > reflect the contents of any one directory on my computer. 
> 
> I meant that the first part of the output is as expected... so the bash
> stuff is correct. Now we can look at the 'why a listing' part...
> 
> 
> > >>>>total 520716
> > >>>>drwxr-sr-x  2 ffreeloader ftp        48 2005-10-13 07:50 script
> > >>>>-rw-r--r--  1 ffreeloader ftp 532692172 2005-10-12 09:38 server_2003.zip
> > >>>>   
> > >>>>
> > >>>>        
> > >>>>
> > >>>this is a listing of your current directory... 
> > >>>
> > >>> 
> > >>>
> > >>>      
> > >>>
> > >>Well, actually I have no one directory that has that exact structure and 
> > >>content.  It looks as if the output shows a couple of sub directories 
> > >>from my /home directory and a file from another directory that that is 
> > >>the default directory for an ftp server. 
> > >>
> > >>    
> > >>
> > >>>>Now in my playing around this morning I've been using some command 
> > >>>>substitution from the bash prompt that included cd'ing into a directory 
> > >>>>that has the files in it that are listed above.  I assume that somehow 
> > >>>>setting $b to the value I set it to is calling the history command in 
> > >>>>the bash shell and that's how I'm getting this output.  However, I don't 
> > >>>>know why or how it works.
> > >>>>   
> > >>>>
> > >>>>        
> > >>>>
> > >>>if you have not editted your .bash* files, re-login afresh and try
> > >>>again. the preceeding para implies you may have (inadvertedly) done
> > >>>something to, say, .bashrc so it executes something on certain
> > >>>conditions and this is where the `ls` output is from.
> > >>>
> > >>> 
> > >>>
> > >>>      
> > >>>
> > >>The only editing I have done to any of my .bash* files is to add a 
> > >>directory, ~/scripts, to the PATH so I can store all my script writing 
> > >>attempts in one directory and execute them without cd'ing there.  That's 
> > >>the sum total of my editing.  The ls output is defintely not from that 
> > >>directory. 
> > >>    
> > >>
> > >
> > >okay, please let us know your PATH and the contents of said ~/scripts
> > >
> > >ta
> > >
> > >
> > >  
> > >
> > Hmmm... You're going to assume that I know nothing about the  contents 
> > and sub directory structure of the directories on my own computer and 
> > what PATH looks like on my computer just because I'm learning bash 
> > scripting and have some questions about script output???? 
> 
> 
> No. I am double checking. Two pairs of eyes better than one
> 
> >  That's more 
> > than just a little insulting, 
> 
> Wasn't meant to be. Life's too busy to spend time typing in insults!
> 
> 
> > but just to show you I know what I'm 
> > talking about when I answer direct questions....
> > 
> > ffreeloader@Job:~/scripts$ ls
> > background.sh                log_cleanup.sh      tmout.sh
> > commandsep.sh                message.sh          update-java-defaults.sh
> > compressdate.sh              position_params.sh  variable_assign.sh
> > control_char.sh              scripts_ls.sh       who.sh
> > echo.sh                      spam2.py            whowhen.sh
> > fileread.sh                  spam.py             wh.sh
> > jre-1_5_0_05-linux-i586.bin  system.py
> > 
> > ffreeloader@Job:~/scripts$ echo $PATH
> > /usr/local/bin:/usr/bin:/bin:/usr/bin/X11:/usr/games:/home/ffreeloader/scripts:
> > 
> > Now, I'll tell you again that the output in question is NOT the contents 
> > of any one directory on my computer. 
> 
> Well I daren't ask anymore in case you bite my head off...
> 
> M

and I guess you've already tried putting a trace on to see exactly
what's happening



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