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Executing Sage with arguments from C with exec family

Hi, I'm writing a piece of software that lets me distribute executions of the type same program-multiple data in a computing server through PVM. This software has a module for Maple executions, one for C, one for Python and one for Pari. Now I'm trying to write the code for a Sage module.

The idea is that i have a master who sends tasks to several slaves, each task consists on executing the same Sage script but using different values for the variables taskId and taskArgs. The slave forks a process and executes a chunk such as this one:

            // NULL-terminated array of strings
            char **args;
            int nargs=2;
            args = (char**)malloc((nargs+1)*sizeof(char*));
            // Do not malloc for NULL
            for (i=0;i<nargs;i++)
                args[i] = malloc(BUFFER_SIZE);
            // Fill up the array with strings
            sprintf(args[1],"-c \"taskId=%d;taskArgs=[%s];load('%s');\"",taskNumber,arguments,inp_programFile);
            args[2] = NULL;
            // Call the execution and check for errors
            err = execvp(args[0],args);
            perror("ERROR:: child Sage process");

For example, an instance of this code would be executing

sage -c "taskId=71;taskArgs=[0,73,74,0];load('test.sage')",

where test.sage prints the arguments or whatever.

Now comes the question. If i execute the previous command from the command line i get the expected result (the two prints). However, if i execute my C program (which works corectly for Maple, C, Python and Pari using a very similar approach) i get this error:

sage-run received unknown option: -c "taskId=71;taskArgs:=[0,73,74,0];load('test.sage')"

I have already tried changing the double quotes " to single quotes ', using only a single, very simple argument from C (e.g. sage -c "print(1);"), all to no avail.

Am I missing something? How can the same command work from the command line but not when i use execvp from within C?

Thanks in advanced for any help!

(I know I could adapt my Python module to read Sage scripts, but i want a standalone module for Sage because the Python one uses sys.args and I'd like to keep the Sage scripts as simple as possible for the users of the software)