HP-UX KSH scripting - passing blank parameters with $# - unix

Question

I have a 'problem' with a script I'm developing in HP-UX KSH. The script contains many functions, and I need to pass the same set of parameters between them. All well and good, but some parameters can be blank. Its easy to pass blank parameters using double double-quotes (""), but what if I want to pass a complete set of parameters from one function into another using ${#}, including blanks? And to make things tricky, there can be a variable number of parameters each time, so the method has to be dynamic.
Example: I've got a function called test1 that takes a number of parameters. Any of them can be blank. I've also created a function called test2 into which all the parameters of test1 are passed:
test1()
{
echo 1-1: ${1}
echo 1-2: ${2}
test2 ${#}
}
test2()
{
echo 2-1: ${1}
echo 2-2: ${2}
}
# test1 "" hello
1-1:
1-2: hello
2-1: hello
2-2:
The trouble is, if ${1} is blank, ${2} from test1 appears as ${1} in test2. So to work around the problem I created this code, which effectively creates a function string with all parameters surrounded with double quotes:
test1()
{
typeset var FUNC="test2"
typeset -i var COUNT=1
echo 1-1: ${1}
echo 1-2: ${2}
while [ ${COUNT} -le ${##} ]; do
typeset var PARAM=$(eval "echo \$${COUNT}")
FUNC="${FUNC} \"${PARAM}\""
((COUNT=COUNT+1))
done
eval "${FUNC}"
}
# test1 "" hello
1-1:
1-2: hello
2-1:
2-2: hello
This works very nicely, thank you. Now to my 'problem'.
Is it actually possible to encapsulate the above code in a function of its own? It seems a catch 22 to me, in that you have to run that code to pass the blank parameters. I have to repeat this code snippet many times in my script because I can't find another way. Is there one?
Any help or guidance will be gratefully received.

Answer 1

Here is how I would write your functions:
show_params() {
typeset funcname=$1
typeset -i n=0
shift
for arg; do
((n++))
printf "%s:%d >%s<\n" "$funcname" $n "$arg"
done
}
test1() { show_params "${.sh.fun}" "$#"; test2 "$#"; }
test2() { show_params "${.sh.fun}" "$#"; }
test1 "" 'a string "with double quotes" in it'
test1:1 ><
test1:2 >a string "with double quotes" in it<
test2:1 ><
test2:2 >a string "with double quotes" in it<
Using your definition of test1, which builds up a string containing a command, adding double quotes around all the paramers, and then eval-ing the string, I get this result
$ test1 "" 'a string "with double quotes" in it'
1-1:
1-2: a string "with double quotes" in it
test2:1 ><
test2:2 >a string with<
test2:3 >double<
test2:4 >quotes in it<
That's because you're doing this:
eval "test2 \"\" \"a string \"with double quotes\" in it\""
# ......... A A A B B A
# A = injected quotes
# B = pre-existing quotes contained in the parameter