C read integers from file (jagged array)

#include <stdio.h>
#include <stdlib.h>

#define MROWS 100
#define MCOLS 20

int main (int argc, char **argv) {

    if (argc < 2) {
        fprintf (stderr, "error: insufficient input.  usage: %s filename\n", argv[0]);
        return 1;
    }

    FILE *fp = fopen (argv[1], "r");
    if (!fp) {
        fprintf (stderr, "error: file open failed for '%s'.\n", argv[1]);
        return 1;
    }

    char *line = NULL;          /* NULL forces getline to allocate  */
    size_t n = 0;               /* max chars to read (0 - no limit) */
    ssize_t nchr = 0;           /* number of chars actually read    */
    int **array = NULL;         /* array of ptrs to array of int    */
    size_t ridx = 0;            /* row index value                  */
    size_t cidx = 0;            /* col index value                  */
    char *endptr = NULL;        /* endptr to use with strtol        */

    /* allocate MROWS (100) pointers to array of int */
    if (!(array = calloc (MROWS, sizeof *array))) {
        fprintf (stderr, "error: array allocation failed\n");
        return 1;
    }

    /* read each line in file */
    while ((nchr = getline (&line, &n, fp)) != -1)
    {
        /* strip newline or carriage return (not req'd) */
        while (line[nchr-1] == '\r' || line[nchr-1] == '\n')
            line[--nchr] = 0;

        if (!nchr)      /* if line is blank, skip */
            continue;

        /* allocate MCOLS (20) ints for array[ridx] */
        if (!(array[ridx] = calloc (MCOLS, sizeof **array))) {
            fprintf (stderr, "error: array[%zd] allocation failed\n", ridx);
            return 1;
        }

        cidx = 0;       /* reset cidx               */
        char *p = line; /* assign pointer to line   */

        /* parse each int in line into array    */
        while ((array[ridx][cidx] = (int)strtol (p, &endptr, 10)) && p != endptr)
        {
            /* checks for underflow/overflow omitted */

            p = endptr; /* increment p      */
            cidx++;     /* increment cidx   */
            /* test cidx = MCOLS & realloc here */
        }
        ridx++;         /* increment ridx   */

        /* test for ridx = MROWS & realloc here */
    }

    /* free memory and close input file */
    if (line) free (line);
    if (fp) fclose (fp);

    printf ("\nArray:\n\n  number of rows with data: %zd\n\n", ridx);

    /* reset ridx, output array values */
    ridx = 0;
    while (array[ridx])
    {
        cidx = 0;
        while (array[ridx][cidx])
        {
            printf ("  array[%zd][%zd] = %d\n", ridx, cidx, array[ridx][cidx]);
            cidx++;
        }
        ridx++;
        printf ("\n");
    }

    /* free allocated memory */
    ridx = 0;
    while (array[ridx])
    {
        free (array[ridx]);
        ridx++;
    }
    if (array) free (array);

    return 0;
}