Question

I am trying to learn C, and I wonder why this doesn’t work?

#include <stdio.h>

int main(int argc, char *argv[])
{
    char testvar[] = argv[0];
    //do something with testvar

    return 0;
}

Answer 1

You could do this instead:

char *testvar = argv[0];

Or maybe:

char *testvar = strdup(argv[0]);
/* Remember to free later. */

As pmg notes, strdup isn’t standard. Implementing it using malloc + memcpy is a nice exercise.

Or even:

char testvar[LENGTH];
if (strlen(argv[0]) >= LENGTH)
    fprintf(stderr, "%s is too long!\n");
else
    strcpy(testvar, argv[0]);

But then again you might be looking for:

char testvar[] = "testvar";