/** * 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>/* apr_table is a dynamic container. So the initial size is not a limitation of the table. */#define TABLE_INIT_SZ           32static int tab_cb(void *data, const char *key, const char *value);/** * add/delete/modify the elements in the table) */static void modify_table(apr_table_t *tab){    /* set (no copy) */    apr_table_setn(tab, "key1", "val1");    /* set (duplicate both key and value)     * internally, apr_pstrdup(mp, "key2") and apr_pstrdup(mp, "val2") are called */    apr_table_set(tab, "key2", "val2");    /* set over-write the old value. see apr_table_get() result below */    apr_table_set(tab, "key2", "over-val2");    /* unset remove the element */    apr_table_setn(tab, "key3", "val3");    apr_table_unset(tab, "key3");    /* add doesn't over-write the old value. see apr_table_get() and iteration results below */    apr_table_add(tab, "key4", "val4");    apr_table_add(tab, "key4", "add-val4");}static void iterate_table(const apr_table_t *tab){    const apr_array_header_t *tarr = apr_table_elts(tab);    const apr_table_entry_t *telts = (const apr_table_entry_t*)tarr->elts;    int i;    for (i = 0; i < tarr->nelts; i++) {        printf("key = %s, val = %s\n", telts[i].key, telts[i].val);    }}/** * dynamic table sample code * @remark Error checks omitted */int main(int argc, const char *argv[]){    apr_pool_t *mp;    apr_table_t *tab;            apr_initialize();    apr_pool_create(&mp, NULL);    /* create a table(key/value string pair container) */    tab = apr_table_make(mp, TABLE_INIT_SZ);    modify_table(tab);        /* get the values from key */    printf("getter: key1:%s key2:%s key3:%s key4:%s unknown-key:%s\n",           apr_table_get(tab, "key1"),           apr_table_get(tab, "key2"),           apr_table_get(tab, "key3"),           apr_table_get(tab, "key4"),           apr_table_get(tab, "unknown-key"));    /* iteration with callback-function. Be careful the final NULL argument is required */    apr_table_do(tab_cb, "label1", tab, NULL);    apr_table_do(tab_cb, "label2", tab, "key1", "key2", NULL);/* iteration with filters */    /* iteration by apr_array_header_t */    iterate_table(tab);    /* table is destroyed when @mp is destroyed */    apr_pool_destroy(mp);    apr_terminate();    return 0;}/* table iteration callback function */static int tab_cb(void *data, const char *key, const char *value){    const char *label = data;    printf("callback[%s]: %s %s\n", label, key, value);    return TRUE;/* TRUE:continue iteration. FALSE:stop iteration */}