超实用PHP函数总结整理，实用php函数总结_PHP教程
- WBOY原创
- 2016-07-13 10:12:20718浏览
超实用PHP函数总结整理，实用php函数总结
1、PHP加密解密
PHP加密和解密函数可以用来加密一些有用的字符串存放在数据库里，并且通过可逆解密字符串，该函数使用了base64和MD5加密和解密。
<span> 1</span> <span>function</span> encryptDecrypt(<span>$key</span>, <span>$string</span>, <span>$decrypt</span><span>){
</span><span> 2</span>
<span> 3</span> <span>if</span>(<span>$decrypt</span><span>){
</span><span> 4</span>
<span> 5</span> <span>$decrypted</span> = <span>rtrim</span>(mcrypt_decrypt(MCRYPT_RIJNDAEL_256, <span>md5</span>(<span>$key</span>), <span>base64_decode</span>
<span> 6</span> (<span>$string</span>), MCRYPT_MODE_CBC, <span>md5</span>(<span>md5</span>(<span>$key</span>))), "12"<span>);
</span><span> 7</span>
<span> 8</span> <span>return</span> <span>$decrypted</span><span>;
</span><span> 9</span>
<span>10</span> }<span>else</span><span>{
</span><span>11</span>
<span>12</span> <span>$encrypted</span> = <span>base64_encode</span>(mcrypt_encrypt(MCRYPT_RIJNDAEL_256, <span>md5</span>(<span>$key</span>),
<span>13</span> <span>$string</span>, MCRYPT_MODE_CBC, <span>md5</span>(<span>md5</span>(<span>$key</span><span>))));
</span><span>14</span>
<span>15</span> <span>return</span> <span>$encrypted</span><span>;
</span><span>16</span>
<span>17</span> <span> }
</span><span>18</span>
<span>19</span> }
使用方法如下：
<span>1</span> <span>//</span><span>以下是将字符串“Helloweba欢迎您”分别加密和解密
</span><span>2</span>
<span>3</span> <span>//加密： </span>
<span>4</span>
<span>5</span> <span>echo</span> encryptDecrypt('password', 'Helloweba欢迎您',0<span>);
</span><span>6</span>
<span>7</span> <span>//</span><span>解密： </span>
<span>8</span>
<span>9</span> <span>echo</span> encryptDecrypt('password', 'z0JAx4qMwcF+db5TNbp/xwdUM84snRsXvvpXuaCa4Bk=',1);
2、PHP生成随机字符串
当我们需要生成一个随机名字，临时密码等字符串时可以用到下面的函数：
<span> 1</span> <span>function</span> generateRandomString(<span>$length</span> = 10<span>) {
</span><span> 2</span>
<span> 3</span> <span>$characters</span> = '0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ'<span>;
</span><span> 4</span>
<span> 5</span> <span>$randomString</span> = ''<span>;
</span><span> 6</span>
<span> 7</span> <span>for</span> (<span>$i</span> = 0; <span>$i</span> < <span>$length</span>; <span>$i</span>++<span>) {
</span><span> 8</span>
<span> 9</span> <span>$randomString</span> .= <span>$characters</span>[<span>rand</span>(0, <span>strlen</span>(<span>$characters</span>) - 1<span>)];
</span><span>10</span>
<span>11</span> <span> }
</span><span>12</span>
<span>13</span> <span>return</span> <span>$randomString</span><span>;
</span><span>14</span>
<span>15</span> }
使用方法如下：
<span>1</span> <span>echo</span> generateRandomString(20);
3、PHP获取文件扩展名（后缀）
以下函数可以快速获取文件的扩展名即后缀。
<span>1</span> <span>function</span> getExtension(<span>$filename</span><span>){
</span><span>2</span>
<span>3</span> <span>$myext</span> = <span>substr</span>(<span>$filename</span>, <span>strrpos</span>(<span>$filename</span>, '.'<span>));
</span><span>4</span>
<span>5</span> <span>return</span> <span>str_replace</span>('.','',<span>$myext</span><span>);
</span><span>6</span>
<span>7</span> }
使用方法如下：
<span>1</span> <span>$filename</span> = '我的文档.doc'<span>; </span><span>2</span> <span>3</span> <span>echo</span> getExtension(<span>$filename</span>);
4、PHP获取文件大小并格式化
以下使用的函数可以获取文件的大小，并且转换成便于阅读的KB，MB等格式。
<span> 1</span> <span>function</span> formatSize(<span>$size</span><span>) {
</span><span> 2</span>
<span> 3</span> <span>$sizes</span> = <span>array</span>(" Bytes", " KB", " MB", " GB", " TB", " PB", " EB", " ZB", " YB"<span>);
</span><span> 4</span>
<span> 5</span> <span>if</span> (<span>$size</span> == 0<span>) {
</span><span> 6</span>
<span> 7</span> <span>return</span>('n/a'<span>);
</span><span> 8</span>
<span> 9</span> } <span>else</span><span> {
</span><span>10</span>
<span>11</span> <span>return</span> (<span>round</span>(<span>$size</span>/<span>pow</span>(1024, (<span>$i</span> = <span>floor</span>(<span>log</span>(<span>$size</span>, 1024)))), 2) . <span>$sizes</span>[<span>$i</span><span>]);
</span><span>12</span>
<span>13</span> <span> }
</span><span>14</span>
<span>15</span> }
使用方法如下：
<span>1</span> <span>$thefile</span> = <span>filesize</span>('test_file.mp3'<span>);
</span><span>2</span>
<span>3</span> <span>echo</span> formatSize(<span>$thefile</span>);
5、PHP替换标签字符
有时我们需要将字符串、模板标签替换成指定的内容，可以用到下面的函数：
<span> 1</span> <span>function</span> stringParser(<span>$string</span>,<span>$replacer</span><span>){
</span><span> 2</span>
<span> 3</span> <span>$result</span> = <span>str_replace</span>(<span>array_keys</span>(<span>$replacer</span>), <span>array_values</span>(<span>$replacer</span>),<span>$string</span><span>);
</span><span> 4</span>
<span> 5</span> <span>return</span> <span>$result</span><span>;
</span><span> 6</span>
<span> 7</span> <span>}
</span><span> 8</span>
<span> 9</span> <span>//</span><span>使用方法如下</span>
<span>10</span>
<span>11</span> <span>$string</span> = '<span>The {b}anchor text{/b} is the {b}actual word{/b} or words used
</span><span>12</span> {br}to describe the link {br}itself'<span>;
</span><span>13</span>
<span>14</span> <span>$replace_array</span> = <span>array</span>('{b}' => '<b>','{/b}' => '</b>','{br}' => '<br >'<span>);
</span><span>15</span>
<span>16</span>
<span>17</span>
<span>18</span> <span>echo</span> stringParser(<span>$string</span>,<span>$replace_array</span>);</br >
6、PHP列出目录下的文件名
如果你想列出目录下的所有文件，使用以下代码即可：
<span> 1</span> <span>function</span> listDirFiles(<span>$DirPath</span><span>){
</span><span> 2</span>
<span> 3</span> <span>if</span>(<span>$dir</span> = <span>opendir</span>(<span>$DirPath</span><span>)){
</span><span> 4</span>
<span> 5</span> <span>while</span>((<span>$file</span> = <span>readdir</span>(<span>$dir</span>))!== <span>false</span><span>){
</span><span> 6</span>
<span> 7</span> <span>if</span>(!<span>is_dir</span>(<span>$DirPath</span>.<span>$file</span><span>))
</span><span> 8</span>
<span> 9</span> <span> {
</span><span>10</span>
<span>11</span> <span>echo</span> "filename: <span>$file</span><br >"<span>;
</span><span>12</span>
<span>13</span> <span> }
</span><span>14</span>
<span>15</span> <span> }
</span><span>16</span>
<span>17</span> <span> }
</span><span>18</span>
<span>19</span> <span>}
</span><span>20</span>
<span>21</span> <span>//</span><span>使用方法如下</span>
<span>22</span>
<span>23</span> listDirFiles('home/some_folder/');
7、PHP获取当前页面URL
以下函数可以获取当前页面的URL，不管是http还是https。
<span> 1</span> <span>function</span><span> curPageURL() {
</span><span> 2</span>
<span> 3</span> <span>$pageURL</span> = 'http'<span>;
</span><span> 4</span>
<span> 5</span> <span>if</span> (!<span>empty</span>(<span>$_SERVER</span>['HTTPS'])) {<span>$pageURL</span> .= "s"<span>;}
</span><span> 6</span>
<span> 7</span> <span>$pageURL</span> .= "://"<span>;
</span><span> 8</span>
<span> 9</span> <span>if</span> (<span>$_SERVER</span>["SERVER_PORT"] != "80"<span>) {
</span><span>10</span>
<span>11</span> <span>$pageURL</span> .= <span>$_SERVER</span>["SERVER_NAME"].":".<span>$_SERVER</span>["SERVER_PORT"].<span>$_SERVER</span>
<span>12</span> ["REQUEST_URI"<span>];
</span><span>13</span>
<span>14</span> } <span>else</span><span> {
</span><span>15</span>
<span>16</span> <span>$pageURL</span> .= <span>$_SERVER</span>["SERVER_NAME"].<span>$_SERVER</span>["REQUEST_URI"<span>];
</span><span>17</span>
<span>18</span> <span> }
</span><span>19</span>
<span>20</span> <span>return</span> <span>$pageURL</span><span>;
</span><span>21</span>
<span>22</span> <span>}
</span><span>23</span>
<span>24</span> <span>//</span><span>使用方法如下</span>
<span>25</span>
<span>26</span> <span>echo</span> curPageURL();
8、PHP强制下载文件
有时我们不想让浏览器直接打开文件，如PDF文件，而是要直接下载文件，那么以下函数可以强制下载文件，函数中使用了application/octet-stream头类型。
<span> 1</span> <span>function</span> download(<span>$filename</span><span>){
</span><span> 2</span>
<span> 3</span> <span>if</span> ((<span>isset</span>(<span>$filename</span>))&&(<span>file_exists</span>(<span>$filename</span><span>))){
</span><span> 4</span>
<span> 5</span> <span>header</span>("Content-length: ".<span>filesize</span>(<span>$filename</span><span>));
</span><span> 6</span>
<span> 7</span> <span>header</span>('Content-Type: application/octet-stream'<span>);
</span><span> 8</span>
<span> 9</span> <span>header</span>('Content-Disposition: attachment; filename="' . <span>$filename</span> . '"'<span>);
</span><span>10</span>
<span>11</span> <span>readfile</span>("<span>$filename</span>"<span>);
</span><span>12</span>
<span>13</span> } <span>else</span><span> {
</span><span>14</span>
<span>15</span> <span>echo</span> "Looks like file does not exist!"<span>;
</span><span>16</span>
<span>17</span> <span> }
</span><span>18</span>
<span>19</span> <span>}
</span><span>20</span>
<span>21</span> <span>//</span><span>使用方法如下</span>
<span>22</span>
<span>23</span> download('/down/test_45f73e852.zip');
9、PHP截取字符串长度
我们经常会遇到需要截取字符串(含中文汉字)长度的情况，比如标题显示不能超过多少字符，超出的长度用…表示，以下函数可以满足你的需求。
<span> 1</span> <span>/*</span>
<span> 2</span>
<span> 3</span> <span> Utf-8、gb2312都支持的汉字截取函数
</span><span> 4</span>
<span> 5</span> <span> cut_str(字符串, 截取长度, 开始长度, 编码);
</span><span> 6</span>
<span> 7</span> <span> 编码默认为 utf-8
</span><span> 8</span>
<span> 9</span> <span> 开始长度默认为 0
</span><span>10</span>
<span>11</span> <span>*/</span>
<span>12</span>
<span>13</span> <span>function</span> cutStr(<span>$string</span>, <span>$sublen</span>, <span>$start</span> = 0, <span>$code</span> = 'UTF-8'<span>){
</span><span>14</span>
<span>15</span> <span>if</span>(<span>$code</span> == 'UTF-8'<span>){
</span><span>16</span>
<span>17</span> <span>$pa</span> = "/[\x01-\x7f]|[\xc2-\xdf][\x80-\xbf]|\xe0[\xa0-\xbf][\x80-\xbf]|[\xe1-\xef][\x80-\xbf][\x80-\xbf]|\xf0[\x90-\xbf][\x80-\xbf][\x80-\xbf]|[\xf1-\xf7][\x80-\xbf][\x80-\xbf][\x80-\xbf]/"<span>;
</span><span>18</span>
<span>19</span> <span>preg_match_all</span>(<span>$pa</span>, <span>$string</span>, <span>$t_string</span><span>);
</span><span>20</span>
<span>21</span>
<span>22</span>
<span>23</span> <span>if</span>(<span>count</span>(<span>$t_string</span>[0]) - <span>$start</span> > <span>$sublen</span>) <span>return</span> <span>join</span>('', <span>array_slice</span>
<span>24</span> (<span>$t_string</span>[0], <span>$start</span>, <span>$sublen</span>))."..."<span>;
</span><span>25</span>
<span>26</span> <span>return</span> <span>join</span>('', <span>array_slice</span>(<span>$t_string</span>[0], <span>$start</span>, <span>$sublen</span><span>));
</span><span>27</span>
<span>28</span> }<span>else</span><span>{
</span><span>29</span>
<span>30</span> <span>$start</span> = <span>$start</span>*2<span>;
</span><span>31</span>
<span>32</span> <span>$sublen</span> = <span>$sublen</span>*2<span>;
</span><span>33</span>
<span>34</span> <span>$strlen</span> = <span>strlen</span>(<span>$string</span><span>);
</span><span>35</span>
<span>36</span> <span>$tmpstr</span> = ''<span>;
</span><span>37</span>
<span>38</span>
<span>39</span>
<span>40</span> <span>for</span>(<span>$i</span>=0; <span>$i</span><<span>$strlen</span>; <span>$i</span>++<span>){
</span><span>41</span>
<span>42</span> <span>if</span>(<span>$i</span>>=<span>$start</span> && <span>$i</span><(<span>$start</span>+<span>$sublen</span><span>)){
</span><span>43</span>
<span>44</span> <span>if</span>(<span>ord</span>(<span>substr</span>(<span>$string</span>, <span>$i</span>, 1))>129<span>){
</span><span>45</span>
<span>46</span> <span>$tmpstr</span>.= <span>substr</span>(<span>$string</span>, <span>$i</span>, 2<span>);
</span><span>47</span>
<span>48</span> }<span>else</span><span>{
</span><span>49</span>
<span>50</span> <span>$tmpstr</span>.= <span>substr</span>(<span>$string</span>, <span>$i</span>, 1<span>);
</span><span>51</span>
<span>52</span> <span> }
</span><span>53</span>
<span>54</span> <span> }
</span><span>55</span>
<span>56</span> <span>if</span>(<span>ord</span>(<span>substr</span>(<span>$string</span>, <span>$i</span>, 1))>129) <span>$i</span>++<span>;
</span><span>57</span>
<span>58</span> <span> }
</span><span>59</span>
<span>60</span> <span>if</span>(<span>strlen</span>(<span>$tmpstr</span>)<<span>$strlen</span> ) <span>$tmpstr</span>.= "..."<span>;
</span><span>61</span>
<span>62</span> <span>return</span> <span>$tmpstr</span><span>;
</span><span>63</span>
<span>64</span> <span> }
</span><span>65</span>
<span>66</span> <span>}
</span><span>67</span>
<span>68</span> <span>//</span><span>使用方法如下</span>
<span>69</span>
<span>70</span> <span>$str</span> = "jQuery插件实现的加载图片和页面效果"<span>;
</span><span>71</span>
<span>72</span> <span>echo</span> cutStr(<span>$str</span>,16);
10、PHP获取客户端真实IP
我们经常要用数据库记录用户的IP，以下代码可以获取客户端真实的IP：
<span> 1</span> <span>//</span><span>获取用户真实IP </span>
<span> 2</span>
<span> 3</span> <span>function</span><span> getIp() {
</span><span> 4</span>
<span> 5</span> <span>if</span> (<span>getenv</span>("HTTP_CLIENT_IP") && <span>strcasecmp</span>(<span>getenv</span>("HTTP_CLIENT_IP"),
<span> 6</span> "unknown"<span>))
</span><span> 7</span>
<span> 8</span> <span>$ip</span> = <span>getenv</span>("HTTP_CLIENT_IP"<span>);
</span><span> 9</span>
<span>10</span> <span>else</span>
<span>11</span>
<span>12</span> <span>if</span> (<span>getenv</span>("HTTP_X_FORWARDED_FOR") && <span>strcasecmp</span>(<span>getenv</span>("HTTP_X_FORWARDED_FOR"), "unknown"<span>))
</span><span>13</span>
<span>14</span> <span>$ip</span> = <span>getenv</span>("HTTP_X_FORWARDED_FOR"<span>);
</span><span>15</span>
<span>16</span> <span>else</span>
<span>17</span>
<span>18</span> <span>if</span> (<span>getenv</span>("REMOTE_ADDR") && <span>strcasecmp</span>(<span>getenv</span>("REMOTE_ADDR"), "unknown"<span>))
</span><span>19</span>
<span>20</span> <span>$ip</span> = <span>getenv</span>("REMOTE_ADDR"<span>);
</span><span>21</span>
<span>22</span> <span>else</span>
<span>23</span>
<span>24</span> <span>if</span> (<span>isset</span> (<span>$_SERVER</span>['REMOTE_ADDR']) && <span>$_SERVER</span>['REMOTE_ADDR'] &&
<span>25</span> <span>strcasecmp</span>(<span>$_SERVER</span>['REMOTE_ADDR'], "unknown"<span>))
</span><span>26</span>
<span>27</span> <span>$ip</span> = <span>$_SERVER</span>['REMOTE_ADDR'<span>];
</span><span>28</span>
<span>29</span> <span>else</span>
<span>30</span>
<span>31</span> <span>$ip</span> = "unknown"<span>;
</span><span>32</span>
<span>33</span> <span>return</span> (<span>$ip</span><span>);
</span><span>34</span>
<span>35</span> <span>}
</span><span>36</span>
<span>37</span> <span>//</span><span>使用方法如下</span>
<span>38</span>
<span>39</span> <span>echo</span> getIp();
11、PHP防止SQL注入
我们在查询数据库时，出于安全考虑，需要过滤一些非法字符防止SQL恶意注入，请看一下函数：
<span> 1</span> <span>function</span> injCheck(<span>$sql_str</span><span>) {
</span><span> 2</span>
<span> 3</span> <span>$check</span> = <span>preg_match</span>('<span>/select|insert|update|delete|\'|\/\*|\*|\.\.\/|\.\/|union|into
</span><span> 4</span> |load_file|outfile/', <span>$sql_str</span><span>);
</span><span> 5</span>
<span> 6</span> <span>if</span> (<span>$check</span><span>) {
</span><span> 7</span>
<span> 8</span> <span>echo</span> '非法字符！！'<span>;
</span><span> 9</span>
<span>10</span> <span>exit</span><span>;
</span><span>11</span>
<span>12</span> } <span>else</span><span> {
</span><span>13</span>
<span>14</span> <span>return</span> <span>$sql_str</span><span>;
</span><span>15</span>
<span>16</span> <span> }
</span><span>17</span>
<span>18</span> <span>}
</span><span>19</span>
<span>20</span> <span>//</span><span>使用方法如下</span>
<span>21</span>
<span>22</span> <span>echo</span> injCheck('1 or 1=1');
12、PHP页面提示与跳转
我们在进行表单操作时，有时为了友好需要提示用户操作结果，并跳转到相关页面，请看以下函数：
<span> 1</span> <span>function</span> message(<span>$msgTitle</span>,<span>$message</span>,<span>$jumpUrl</span><span>){
</span><span> 2</span> <span>$str</span> = '<!DOCTYPE HTML>'<span>;
</span><span> 3</span> <span>$str</span> .= '<html>'<span>;
</span><span> 4</span> <span>$str</span> .= '<head>'<span>;
</span><span> 5</span> <span>$str</span> .= '<meta charset="utf-8">'<span>;
</span><span> 6</span> <span>$str</span> .= '<title>页面提示</title>'<span>;
</span><span> 7</span> <span>$str</span> .= '<style type="text/css">'<span>;
</span><span> 8</span> <span>$str</span> .= '<span>*{margin:0; padding:0}a{color:#369; text-decoration:none;}a:hover{text-decoration:underline}body{height:100%; font:12px/18px Tahoma, Arial, sans-serif; color:#424242; background:#fff}.message{width:450px; height:120px;
</span><span> 9</span> <span>margin:16% auto; border:1px solid #99b1c4; background:#ecf7fb}.message h3{height:28px;
</span><span>10</span> line-height:28px; background:#2c91c6; text-align:center; color:#fff; font-size:14px}.msg_txt{padding:10px; margin-top:8px}.msg_txt h4{line-height:26px; font-size:14px}.msg_txt h4.red{color:#f30}.msg_txt p{line-height:22px}'<span>;
</span><span>11</span> <span>$str</span> .= '</style>'<span>;
</span><span>12</span> <span>$str</span> .= '</head>'<span>;
</span><span>13</span> <span>$str</span> .= '<body>'<span>;
</span><span>14</span> <span>$str</span> .= '<div>'<span>;
</span><span>15</span> <span>$str</span> .= '<h3>'.<span>$msgTitle</span>.'</h3>'<span>;
</span><span>16</span> <span>$str</span> .= '<div>'<span>;
</span><span>17</span> <span>$str</span> .= '<h4>'.<span>$message</span>.'</h4>'<span>;
</span><span>18</span> <span>$str</span> .= '<p>系统将在 <span>;
</span><span>19</span> <span>$str</span> .= "<script>setTimeout('location.replace(\'".<span>$jumpUrl</span>."\')',2000)</script>"<span>;
</span><span>20</span> <span>$str</span> .= '</div>'<span>;
</span><span>21</span> <span>$str</span> .= '</div>'<span>;
</span><span>22</span> <span>$str</span> .= '</body>'<span>;
</span><span>23</span> <span>$str</span> .= '</html>'<span>;
</span><span>24</span> <span>echo</span> <span>$str</span><span>;
</span><span>25</span> <span>}
</span><span>26</span>
<span>27</span> <span>//</span><span>使用方法如下 </span>
<span>28</span>
<span>29</span> message('操作提示','操作成功！','http://www.helloweba.com/');
13、PHP计算时长
我们在处理时间时，需要计算当前时间距离某个时间点的时长，如计算客户端运行时长，通常用hh:mm:ss表示。
<span> 1</span> <span>function</span> changeTimeType(<span>$seconds</span><span>) {
</span><span> 2</span>
<span> 3</span> <span>if</span> (<span>$seconds</span> > 3600<span>) {
</span><span> 4</span>
<span> 5</span> <span>$hours</span> = <span>intval</span>(<span>$seconds</span> / 3600<span>);
</span><span> 6</span>
<span> 7</span> <span>$minutes</span> = <span>$seconds</span> % 3600<span>;
</span><span> 8</span>
<span> 9</span> <span>$time</span> = <span>$hours</span> . ":" . <span>gmstrftime</span>('%M:%S', <span>$minutes</span><span>);
</span><span>10</span>
<span>11</span> } <span>else</span><span> {
</span><span>12</span>
<span>13</span> <span>$time</span> = <span>gmstrftime</span>('%H:%M:%S', <span>$seconds</span><span>);
</span><span>14</span>
<span>15</span> <span> }
</span><span>16</span>
<span>17</span> <span>return</span> <span>$time</span><span>;
</span><span>18</span>
<span>19</span> <span>}
</span><span>20</span>
<span>21</span> <span>//</span><span>使用方法如下</span>
<span>22</span>
<span>23</span> <span>$seconds</span> = 3712<span>;
</span><span>24</span>
<span>25</span> <span>echo</span> changeTimeType(<span>$seconds</span>);
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