I understand that, but that is only in the case of

Code:

 while IFS=: read ...

what I am saying is I have been told to do it differently in the format of:

Code:

OLDIFS=$IFS
IFS=":\n"

I am unsure why exactly I must use OLDIFS, but I assume it's a problem with sh? so far all tests I have done using IFS in while loop in sh, ash, bash, ksh all seem to work fine... So I really have no idea why my tutor seems to think otherwise, would have been helpful if I asked him to expand on this..


I think the basic logic behind it is, 'sh' doesn't handle subshells very well, while bash/ksh etc do handle subshells fine. But the tutor is trying to teach us portable languages.

Like I have already mentioned my problems using OLDIFS variable is that my constant variables that i use to echo statements to standard output are missing the n's

Code:

 
 ew record added to database
 ew record added to database
 ew record added to database

however this is NOT for all my variables I have just checked over and tested a few of them, and they work, however addding, and failure to delete is leaving out n's, which seems wierd to me. You would think they all would not work, or they all would work. Not randomly willy nilly.
As you can see from my first post, I showed the while loop calling functions, so in the case of using OLDIFS/NEWIFS I assume those functions and variables called from there also use it. which is why i'm missing some "n's"

Code:

# arg errors
USAGE="usage: ./a3 -d dataBaseFilename -o operationsFilename"
ERRNOARG="error:Invalid command line not enough arguments"
ERRNOFILE="error:No operations file supplied"
ERRNOREAD="error:can't read"
ERROPEMPTY="error:Operations file empty"
ERRILLOPT="illegal options:"

# opt errors
ERRNOADD="unable to add"
ADDFORMAT="add:product:brand:isle"
ERRNODEL="not deleted does not exist"
DELFORMAT="delete:product:brand"
ERRNOBRAND="brand does not exist"
ERRNOPROD="does not exist"
ERROPERATE="unknown operation"
ERREXISTS="product already exists"

# common output
RECADDED="new record added to database"
DATAEMPTY="database is empty - nothing to display"
RECDELETE=":deleted"

readonly USAGE ERRNOARG ERRNOFILE ERRNOREAD ERROPEMPTY
readonly ERRILLOPT ERRNOADD ERRNODEL ERRNOBRAND ERRNOPROD
readonly ERROPERATE ERREXISTS RECADDED DATAEMPTY RECDELETE

DATAEMPTY seems to work, as does USAGE...
RECADDED does not

thanks for the help, if you need to see more of my code, eg where I am calling the variables from just ask