array-sample.c

跨平台windowsunixlinux的c语言编程解决方案

/**
 * apr tutorial sample code
 * http://dev.ariel-networks.com/apr/
 */
#ifdef HAVE_CONFIG_H
#include <config.h>
#endif

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

#include <apr_general.h>
#include <apr_tables.h>
#include <apr_strings.h>

/* apr_array's initial size.
 * because apr_array is a dynamic array, the initial size is not a max size of the array. */
#define ARRAY_INIT_SZ           32

static void append_items_to_array(apr_array_header_t *arr, apr_pool_t *mp)
{
    *(const char**)apr_array_push(arr) = "123";
    *(const char**)apr_array_push(arr) = "456";
    *(const char**)apr_array_push(arr) = "789";
    /* it's often a good idea to have elements in the same memory pool */
    *(const char**)apr_array_push(arr) = apr_pstrdup(mp, "abcdef");
    *(const char**)apr_array_push(arr) = apr_pstrdup(mp, "ghijkl");
}

static void iterate_array(const apr_array_header_t *arr)
{
    int i;
    for (i = 0; i < arr->nelts; i++) {
        const char *s = ((const char**)arr->elts)[i];
        printf("%d: %s\n", i, s);
    }
}

/**
 * you can use array as stack (first-in, last-out)
 */
static void iterate_stack_array(apr_array_header_t *arr)
{
    const char **ppt;
    while ((ppt = apr_array_pop(arr))) {
        printf("pop'd string: %s\n", *ppt);
    }
}

/**
 * apr_array sample code
 * @remark Error checks omitted
 */
int main(int argc, const char *argv[])
{
    apr_pool_t *mp;
    apr_array_header_t *arr;
        
    apr_initialize();
    apr_pool_create(&mp, NULL);

    /* Create a dynamic array of string('const char*') */
    arr = apr_array_make(mp, ARRAY_INIT_SZ, sizeof(const char*));

    append_items_to_array(arr, mp);

    /* array iteration example */
    iterate_array(arr);

    /* concatenate the all items.
     * We can do this, because the array is the array of string. */
    printf("array concat = %s\n", apr_array_pstrcat(mp, arr, '\0'));

    /* yet another iteration, but removing the items */
    iterate_stack_array(arr);

    /* the array is destroyed when @mp is destroyed */
    apr_pool_destroy(mp);
    
    apr_terminate();
    return 0;
}