tpop(2.6): Growing arrays example code

/* tpop(1.5): growing array
   created on Mar 17, 2011 */
#include    "stdio.h"

typedef struct Nameval Nameval;

struct Nameval {
    char *name;
    int value;
};

struct NVtab {
    int nval;
    int max;
    Nameval *nameval;
} nvtab;

enum { NVINIT = 1, NVGROW = 2};

/* main: growing array */
int main(int argc, char *argv[])
{
      int i;
      Nameval new;
    new.name = "mark";
    new.value = "23";
    if ((i = addname(new)) != -1)
      printf("Name is %s \n", nvtab.nameval[i].name);
    i = delname("mark");
    printf ("%d\n", i);
}
/* addname: add new name and value to nvtab */
int addname(Nameval newname)
{
    Nameval *nvp;
    if (nvtab.nameval == NULL) {/* first time */
        nvtab.nameval = (Nameval *)malloc(NVINIT * sizeof(Nameval));
        if (nvtab.nameval == NULL)
          return -1;
        nvtab.max = NVINIT;
        nvtab.nval = 0;
    } else if (nvtab.nval >= nvtab.max) { /* grow */
        nvp = (Nameval *) realloc(nvtab.nameval, (NVGROW*nvtab.max) * sizeof(Nameval));
        if (nvp == NULL)
          return -1;
        nvtab.max *= NVGROW;
        nvtab.nameval = nvp;
    }
    nvtab.nameval[nvtab.nval] = newname;
    return nvtab.nval++;

}

/* delname: remove first maching nameval from nvtab */
int delname(char *name)
{
    int i;
    for (i = 0; i < nvtab.nval; i++)
      if (strcmp(nvtab.nameval[i].name, name) == 0) {
          memmove(nvtab.nameval+i, nvtab.nameval+i+1, (nvtab.nval-(i+1)) * sizeof(Nameval));
          nvtab.nval--;
          return 1;
      }
    return 0;
}