You already get very sound advice but you might probably want to know why this doesn't work in the form you wrote it:

The shell evaluates a commandline in certain steps. All the evaluation in a certain step is done at once. For instance:

Code:

A="foo"
B="bar"

# command1 $A | command2 $B

"$A" and "$B" are expanded to their respective values at the same time. This is why the following:

Code:

A='$B'
B="bar"

# command1 $A

will provide command1 not with "bar" but with a literal "$B". When the step "evaluate variables" is done and "$A" is replaced by its value "$B" there will be no further evaluation of "$B" to "bar".

Furthermore, when the shell evaluates a variable it surrounds it by so-called "IFS" (internal field separator) characters. This IFS character is per default a blank but for the next evaluation of a command the shell is aware that there is a difference between a simple blank inside a variables value and an IFS character separating two arguments. here is another example for exactly the same problem, this time created by the guys who develop the operating system.

If you need a solution to such problems (you won't need it here, because you got better procedures already) there is: the eval command. I said that the shell is aware of the difference between a simple space and the IFS character, but only so for ONE evaluation. Fortunately you can (re-)start the command evaluation with a certain keyword, which is "eval". Just prepend your command with it and the shell will evaluate your command line, then evaluate the result again, and only then execute it. This way you could do:

Code:

A='$B'
B="bar"

# eval command1 $A

and have "bar" as argument to command1. In the first evaluation "$A" will be replaced by "$B" and in the second pass "$B" will be replaced by "bar". This will also work for your construct:

Code:

IGNOREFILES="grep -v .txt | grep -v .csv"
# eval find $SDIRNAME/* -prune -type f -mtime +$MTIME -exec ls -ltr {} \; | $IGNOREFILES

I hope this helps.

bakunin