PHP学习：php使用ftp实现文件上传与下载功能

<?php
$host = '10.0.0.42';
$user = 'uftp';
$pwd = 'uftp';
// 进行ftp连接,根据port是否设置,传递的参数会不同
if(empty($port)){
    $f_conn = ftp_connect($host);
}else{
    $f_conn = ftp_connect($host, $port);
}
if(!$f_conn){
    echo "connect fail\n";
    exit(1);
}
echo "connect success\n";
// 进行ftp登录,使用给定的ftp登录用户名和密码进行login
$f_login = ftp_login($f_conn,$user,$pwd);
if(!$f_login){
    echo "login fail\n";
    exit(1);
}
echo "login success\n";
// 获取当前所在的ftp目录
$in_dir = ftp_pwd($f_conn);
if(!$in_dir){
    echo "get dir info fail\n";
    exit(1);
}
echo "$in_dir\n";
// 获取当前所在ftp目录下包含的目录与文件
$exist_dir = ftp_nlist($f_conn, ftp_pwd($f_conn));
print_r($exist_dir);
// 要求是按照日期在ftp目录下创建文件夹作为文件上传存放目录
echo date("Ymd")."\n";
$dir_name = date("Ymd");
// 检查ftp目录下是否已存在当前日期的文件夹,如不存在则进行创建
if(!in_array("$in_dir/$dir_name", $exist_dir)){
    if(!ftp_mkdir($f_conn, $dir_name)){
        echo "mkdir fail\n";
        exit(1);
    }else{
        echo "mkdir $dir_name success\n";
    }
}
// 切换目录
if(!ftp_chdir($f_conn, $dir_name)){
    echo "chdir fail\n";
    exit(1);
}else{
    echo "chdir $dir_name success\n";
}
// 进行文件上传
$result = ftp_put($f_conn, 'bbb.mp3', '/root/liang/ftp/bbb.mp3', FTP_BINARY);
if(!$result){
    echo "upload file fail\n";
    exit(1);
}else{
    echo "upload file success\n";
    exit(0);
}

root@webdevelop232:~/liang/ftp# php ftp.php 
connect success
login success
/home/uftp
Array
(
  [0] => /home/uftp/Kalimba.mp3
  [1] => /home/uftp/test.txt
)
20170721
mkdir 20170721 success
chdir 20170721 success
upload file success

<?php
$host = '10.0.0.42';
$uname = 'uftp';
$upwd = 'uftp';
// 进行ftp连接
if(empty($port)){
  $f_conn = ftp_connect($host);
}else{
  $f_conn = ftp_connect($host, $port);
}
if(!$f_conn){
  echo "ftp connect fail\n";
  exit(1);
}
// 进行ftp登录
if(!ftp_login($f_conn, $uname, $upwd)){
  echo "ftp login fail\n";
  exit(1);
}
// 进行ftp下载
if(!ftp_get($f_conn, './1.mp3', ftp_pwd($f_conn).'/'.date('Ymd').'/bbb.mp3', FTP_BINARY)){
  echo "ftp download fail\n";
  exit(1);
}else{
  echo "ftp download success\n";
  exit(0);
}