Re: [Bashburn-info] I think I fixed the AUTHOR problem.

[Steven W. O. <st...@sy...>]

On Sunday, Sep 21st 2008 at 18:35 -0000, quoth Anders Lind?n:

=>Yeah thats pretty much what I meant. Telling the shell which characters
=>are to be used to separate fields.
=>
=>Question, why are you setting a new IFS and shortly after set it back to
=>the old IFS in loops?
=>Is it because programs used in the loop needs the original IFS to work
=>properly?

Correct. In some cases, it's actually *not* used, but it's good practice 
to restore IFS right after you're done with it. Sometimes you end up using 
it and you're not aware of it. I usually lose a few minutes chasing 
problems when that happens.  :-(

=>On another note, I noticed when starting the latest svn snapshot of BB,
=>it spits out an error message
=>that the command die does not exist. I'm guessing because you have not
=>sourced the needed file yet at that point.   

Good catch. Fixed.

=>
=>
=>On Sun, 2008-09-21 at 18:20 -0400, Steven W. Orr wrote:
=>> On Sunday, Sep 21st 2008 at 16:34 -0000, quoth Anders Lind?n:
=>> 
=>> =>Meh, I sent my reply to Steven and not the list. Reposting it here.
=>> =>
=>> =>If I'm not mistaken, IFS is something that is treated as a space or
=>> =>newline character no? You can set a character like @, : or | in our case
=>> =>to be treated as a whitespace to separate text fields?
=>> =>
=>> =>On Sun, 2008-09-21 at 16:17 -0400, Steven W. Orr wrote:
=>> =>> It looks like we have three different values that are being used for IFS. 
=>> =>> There's the IFS=: which is needed to read a bbrc file. There's IFS=@ used 
=>> =>> to pass uneval'd data to bbconfmenu. And now there's IFS='|' which is 
=>> =>> needed to store configure_changes. (BTW, the implication is that a config 
=>> =>> val may no longer contain an embedded pipe char.)
=>> =>> 
=>> =>> Nick, I hope this works. There's always one guy who screws up and makes 
=>> =>> people aware that he's good at testing. I consider it a blessing. ;-) The 
=>> =>> good news is that if you find anything wrong with it, it should be easy to 
=>> =>> fix. (I try to never let people know that I know how to get the printer
=>> =>> working. ;-)
=>> =>> 
=>> =>> On a related topic, I was just curious. Do people understand what IFS is 
=>> =>> and what I'm doing with it? How it gets restored? etc...?
=>> 
=>> Close. IFS is used as the mechanism to tell bash how to parse text. For 
=>> example, if I have
=>> 
=>> foo='This is a string: It has some stuff in it. And it's 2:00PM.'
=>> then I can say
=>> set -- $foo
=>> After the set command, 
=>> $1 will be 'This'
=>> $2 will be 'is'
=>> $3 will be 'a'
=>> and $4 will be 'string:'
=>> 
=>> But if I was to say
=>> IFS=:
=>> set -- $foo
=>> then $1 will be 'This is a string'
=>> $2 will be ' It has some stuff in it. And it's 2'
=>> and $3 will be '00PM.'
=>> 
=>> In addition, lists will be taken apart differently (for example is for 
=>> loops, depending on IFS. All the values of IFS that I work with are local 
=>> copies in subroutines. e.g.,
=>> 
=>> subX()
=>> {
=>>     typeset old_IFS="$IFS"
=>>     typeset IFS="$old_IFS"
=>> 
=>> The default value for IFS is whitespace
=>> 
=>> 533 > echo "$IFS" | od -bc
=>> 0000000 040 011 012 012
=>>              \t  \n  \n
=>> 0000004
=>> 
=>> 
=>-- 
=>Anders Lind?n
=>http://bashburn.sf.net
=>
=>
=>-------------------------------------------------------------------------
=>This SF.Net email is sponsored by the Moblin Your Move Developer's challenge
=>Build the coolest Linux based applications with Moblin SDK & win great prizes
=>Grand prize is a trip for two to an Open Source event anywhere in the world
=>http://moblin-contest.org/redirect.php?banner_id=100&url=/
=>_______________________________________________
=>Bashburn-info mailing list
=>Bas...@li...
=>https://lists.sourceforge.net/lists/listinfo/bashburn-info
=>

-- 
steveo at syslang dot net TMMP1 http://frambors.syslang.net/
Do you have neighbors who are not frambors? Steve Orr
Who should we vote for? http://steveo.syslang.net/electionrec-2008/