ksh double quotes and variables

Question

It's a KSH problems.

I have encounter some problems with variables and quotation marks today. Order doesn't matter, although i cannot read the scripts but only execute it.

SomeScripts.sh "First=Harvey Lo","Third=Rebecca Won","Second=laugh at"

Results:

Harvey Lo laugh at Rebecca Won

but If i try to put it in a ksh scripts file, it doesn't work:

#!/bin/ksh
SOMEVAR=\"First=Harvey Lo\",\"Third=Rebecca Won\",\"Second=laugh at\"
SomeScripts.sh ${SOMEVAR}

Results:

Error: No. of ARGS > 3

I even try the following, but still not work.

#!/bin/ksh
SOMEVAR=\"First=Harvey Lo\",\"Third=Rebecca Won\",\"Second=laugh at\"
SomeScripts.sh `echo ${SOMEVAR}`

Results:

Error: No. of ARGS > 3

can anyone help, all i know that there is some java inside the SomeScripts.sh, the actual function have more than 20 parameters, but i have simplified as shown.

The Original Help File:

SomeScripts.sh First=Harvey,Third=Rebecca,Second=laugh
Harvey laugh Rebecca

Answer 1

You need to realize that your first example has only one parameter, and the way it is quoted is only a detail. These are identical:

SomeScripts.sh "First=Harvey Lo","Third=Rebecca Won","Second=laugh at"

SomeScripts.sh "First=Harvey Lo,Third=Rebecca Won,Second=laugh at"

So the way to make it work is not to put \" inside the variable – instead you need to quote it while it is being set:

SOMEVAR="First=Harvey Lo","Third=Rebecca Won","Second=laugh at"

Again, this is equivalent to a simple

SOMEVAR="First=Harvey Lo,Third=Rebecca Won,Second=laugh at"

You also need to quote the variable when it is used, otherwise it will be subject to word-splitting after being expanded. (Word-splitting here means just splitting by spaces.) The same applies to ` ` substitution as well.

SomeScripts.sh "$SOMEVAR"

Try compiling this program and running it with differently quoted arguments – it will show you exactly what it receives as arguments.

#include <stdio.h>
int main(int argc, char *argv[]) {
    printf("argc = %d\n", argc);
    for (argc=0; argv[argc]; argc++)
        printf("argv[%d] = %s\n", argc, argv[argc]);
    return 0;
}