My function is being passed a struct containing, among other things, a NULL terminated array of pointers to words making up a command with arguments.

I'm performing a glob match on the list of arguments, to expand them into a full list of files, then I want to replace the passed argument array with the new expanded one.

The globbing is working fine, that is, g.gl_pathv is populated with the list of expected files. However, I am having trouble copying this array into the struct I was given.

#include <glob.h>

struct command {
  char **argv;
  // other fields...
}

void myFunction( struct command * cmd )
{
  char **p = cmd->argv;
  char* program = *p++; // save the program name (e.g 'ls', and increment to the first argument

  glob_t g;
  memset(&g, 0, sizeof(g));
  int res = glob(*p, 0, NULL, &g);
  *p++ // increment
  while (*p)
  {
      glob(*p++, GLOB_APPEND, NULL, &g); // append the matches
  }

  // here i want to replace cmd->argv with the expanded g.gl_pathv
  memcpy(cmd->argv, g.gl_pathv, g.gl_pathc ); // this doesn't work
  globfree(&g);
}