apache 的apr函数库简单学习

1. 基本框架和内存池的使用

#define MEM_ALLOC_SZ 1024
int main(int argc, const char * const argv[])
{
apr_pool_t * pool;//内存池
apr_status_t rv;
char * buf;

rv = apr_initialize();//初始化
if( rv != APR_SUCCESS ){
return -1;
}
rv = apr_pool_create(&pool,NULL);//创建内存池
if( rv != APR_SUCCESS ){
return -1;
}

buf = apr_palloc(pool,MEM_ALLOC_SZ);//分配一个内存块
//apr_pool_clear(pool);
strcpy(buf,"test");
printf("this is a %s\n",buf);

apr_pool_destroy(pool);//销掉内存池对象
apr_terminate();//结束

return APR_SUCCESS;
}

2.文件操作

#define MEM_ALLOC_SIZE 1024
int main(int argc, const char * const argv[])
{
apr_pool_t * pool;//内存池
apr_status_t rv;
char * buf;
char * contentBuf;
apr_file_t * fin;
apr_file_t * fout;
apr_size_t len;
apr_finfo_t finfo;//用来保存文件信息的结构体

rv = apr_initialize();//初始化
rv = apr_pool_create(&pool,NULL);//创建pool
buf = apr_palloc(pool,MEM_ALLOC_SIZE);//给buf分配空间

rv = apr_file_open(&fin,"d:\\in.txt",APR_READ|APR_BUFFERED,APR_OS_DEFAULT,pool);//打开可读文件
if( rv == APR_SUCCESS ){
strcpy(buf,"fileread_open succeed!");
printf("this is a test:%s\n",buf);
}
apr_file_lock(fin,APR_FLOCK_SHARED);//读锁,允许其他读者进线程对它读，但不能有写者对它操作
/*
* 打开可写文件
* 其中APR_CREATE表示若没有该文件则创建一个，APR_TRUNCATE表示若文件有内容则全部删掉（APR_APPEND为在文件末添加）
*/
rv = apr_file_open(&fout,"d:\\out.txt",APR_WRITE|APR_BUFFERED|APR_CREATE|APR_TRUNCATE,APR_OS_DEFAULT,pool);
if( rv == APR_SUCCESS ){
strcpy(buf,"filewrite_open succeed!");
printf("this is a test:%s\n",buf);
}
apr_file_lock(fout,APR_FLOCK_EXCLUSIVE);//写锁，不允许其他进程对此文件操作
/*
* 将in.txt文件中的内容全部复制到out.txt文件中
*/
contentBuf = apr_palloc(pool,MEM_ALLOC_SIZE);
do{
apr_file_read(fin,contentBuf,&len);
//contentBuf[len] = 0;
apr_file_write(fout,contentBuf,&len);
} while( len != 0 );

//关闭文件in.txt
apr_file_unlock(fin);
apr_file_close(fin);

/*
* 将复制in.txt为in_bak.txt，同时删掉in.txt文件
*/
apr_file_copy("d:\\in.txt","d:\\in_bak.txt",APR_OS_DEFAULT,pool);
apr_file_remove("d:\\in.txt",pool);

apr_file_info_get(&finfo,APR_FINFO_NAME,fout);//获取文件信息方法1：通过文件对象
printf("file name is:%s",finfo.fname);

apr_stat(&finfo,"d:\\in_bak.txt",APR_FINFO_SIZE,pool);//获取文件信息方法2：通过文件路径
printf("file size is:%d bytes",finfo.size);

//关闭文件out.txt
apr_file_unlock(fout);
apr_file_close(fout);

apr_pool_destroy(pool);//销掉内存池对象
apr_terminate();//结束
return APR_SUCCESS;

}

3 目录操作

#define MEM_ALLOC_SIZE 1024
void traversal(char * dirPath, apr_pool_t * pool) {//-r遍历该目录下的所有文件

apr_finfo_t finfo;//用来保存文件信息的结构体
apr_dir_t *dir;
if( apr_dir_open(&dir,dirPath,pool) != APR_SUCCESS ) return;//获得目录对象，若不成功则直接返回

while(apr_dir_read(&finfo,APR_FINFO_NAME|APR_FINFO_TYPE,dir) == APR_SUCCESS ) {//读该目录下的所有文件信息，存到finfo中
if( finfo.filetype == APR_DIR ) {//该文件是目录对象
if( strcmp(finfo.name,".") == 0 || strcmp(finfo.name,"..") == 0 ) {//该文件是.或..，则继续
continue;
}else {//该文件是目录，且不是.或..，则递归进入
char * subDirPath;
subDirPath = apr_pstrcat(pool,dirPath,"\\",finfo.name,NULL);//subDirPath = dirPath + "\\" + finfo.name + NULL
traversal(subDirPath,pool);
}
}else if( finfo.filetype == APR_REG ) {//文件是普通文件，输出
printf("%s\\%s\n",dirPath,finfo.name);
}else {
printf("非正常文件:%s\\%s\n",dirPath,finfo.name);//文件是非普通文件，输出
}
}
}
int main(int argc, const char * const argv[])
{
apr_pool_t * pool;//内存池
apr_status_t rv;

rv = apr_initialize();//初始化
rv = apr_pool_create(&pool,NULL);//创建pool

traversal("d:",pool);//开始遍历

apr_pool_destroy(pool);//销掉内存池对象
apr_terminate();//结束
return APR_SUCCESS;

}

4 自定义命令行参数

static const apr_getopt_option_t cmd_option[] = {
{"in",'i',TRUE,"input filename"},
{"out",'o',TRUE,"output filename"},
{"help",'h',FALSE,"show help information"},
{NULL,0,0,NULL},//哨兵
};
#define MEM_ALLOC_SIZE 1024
int main(int argc, const char * const argv[])
{
apr_pool_t * pool;//内存池
apr_status_t rv;
apr_getopt_t * opt;
int optch;
char * optarg;
rv = apr_initialize();//初始化
rv = apr_pool_create(&pool,NULL);//创建pool

apr_getopt_init(&opt,pool,argc,argv);//将命令行内容填入opt结构中

while( (rv = apr_getopt_long(opt,cmd_option,&optch,&optarg)) == APR_SUCCESS ) {//一个一个解析命令
switch(optch) {
case 'i':
printf("i参数是%s",optarg);
break;
case 'o':
printf("o参数是%s",optarg);
break;
case 'h':
printf("h没有参数");
break;
default:
break;
}
}

if( rv != APR_EOF ){//判断是否全部解析
printf("解析命令行错误！");
}

apr_pool_destroy(pool);//销掉内存池对象
apr_terminate();//结束
return APR_SUCCESS;

}