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Summary and arrangement of super practical PHP functions
- WBOYOriginal
- 2016-08-08 09:33:02819browse
1. PHP encryption and decryption
PHP encryption and decryption functions can be used to encrypt some useful strings stored in the database, and reversibly decrypt the strings. This function uses base64 and MD5 encryption and decryption.
<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> }
How to use is as follows:
<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 generates random strings
When we need to generate a random name, temporary password and other strings, we can use the following function:
<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>$randomString</span><span>;
</span><span>14</span>
<span>15</span> }
How to use it:
<span>1</span> <span>echo</span> generateRandomString(20);
3. PHP gets the file extension (suffix)
The following function can quickly obtain the file extension or suffix.
<span>1</span> <span>function</span> getExtension(<span>$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> }
How to use is as follows:
<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 gets the file size and formats it
The functions used below can get the size of the file and convert it into easy-to-read KB, MB and other formats.
<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> }
How to use is as follows:
<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. Replace tag characters with PHP
Sometimes we need to replace strings and template tags with specified content, we can use the following function:
<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>$replace_array</span>);</br >
6. PHP lists the file names in the directory
If you want to list all files in a directory, use the following code:
<span> 1</span> <span>function</span> listDirFiles(<span>$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>$file</span><br >"<span>;
</span><span>12</span>
<span>13</span> <span> }
</span><span>14</span>
<span>15</span> <span> }
</span><span>16</span>
<span>17</span> <span> }
</span><span>18</span>
<span>19</span> <span>}
</span><span>20</span>
<span>21</span> <span>//</span><span>使用方法如下</span>
<span>22</span>
<span>23</span> listDirFiles('home/some_folder/');
7. Get the current page URL with PHP
The following function can get the URL of the current page, whether it is http or https.
<span> 1</span> <span>function</span><span> curPageURL() {
</span><span> 2</span>
<span> 3</span> <span>$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 forced download of files
Sometimes we don’t want the browser to directly open a file, such as a PDF file, but to download the file directly, then the following function can force the file to be downloaded. The application/octet-stream header type is used in the function.
<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 intercepts string length
We often encounter situations where we need to intercept the length of a string (including Chinese characters). For example, the title display cannot exceed how many characters. The excess length is represented by.... The following function can meet your needs.
<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>$str</span>,16);
10. Get the real IP of the client with PHP
We often use a database to record the user’s IP. The following code can obtain the client’s real IP:
<span> 1</span> <span>//</span><span>获取用户真实IP </span>
<span> 2</span>
<span> 3</span> <span>function</span><span> getIp() {
</span><span> 4</span>
<span> 5</span> <span>if</span> (<span>getenv</span>("HTTP_CLIENT_IP") && <span>strcasecmp</span>(<span>getenv</span>("HTTP_CLIENT_IP"),
<span> 6</span> "unknown"<span>))
</span><span> 7</span>
<span> 8</span> <span>$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>$ip</span><span>);
</span><span>34</span>
<span>35</span> <span>}
</span><span>36</span>
<span>37</span> <span>//</span><span>使用方法如下</span>
<span>38</span>
<span>39</span> <span>echo</span> getIp();
11. PHP prevents SQL injection
When we query the database, for security reasons, we need to filter some illegal characters to prevent malicious SQL injection. Please take a look at the function:
<span> 1</span> <span>function</span> injCheck(<span>$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 page prompts and jumps
When we perform form operations, sometimes we need to prompt the user for the operation results and jump to the relevant page for the sake of friendliness. Please see the following function:
<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>3</span> 秒后自动跳转,如果不想等待,直接点击 <a href="{$jumpUrl}">这里</a> 跳转</p>'<span>;
</span><span>19</span> <span>$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 calculation time
When we process time, we need to calculate the length of time from the current time to a certain point in time. For example, when calculating the running time of the client, it is usually expressed by hh:mm:ss.
<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>);
The above has introduced a summary of super practical PHP functions, including relevant content. I hope it will be helpful to friends who are interested in PHP tutorials.
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