Introduction to file_get_contents and curl_get_contents in php

Share an actually used function:

The file_get_contents () function is the preferred method for reading the file content into a string. If supported by the operating system, the memory ing technology will be used to enhance the performance.

/* More stable than file_get_contents! $ Timeout is the timeout time in seconds. The default value is 1 s. */

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Function curl_get_contents ($ url, $ timeout = 1 ){ $ CurlHandle = curl_init (); Curl_setopt ($ curlHandle, CURLOPT_URL, $ url ); Curl_setopt ($ curlHandle, CURLOPT_RETURNTRANSFER, 1 ); Curl_setopt ($ curlHandle, CURLOPT_TIMEOUT, $ timeout ); $ Result = curl_exec ($ curlHandle ); Curl_close ($ curlHandle ); Return $ result; } $ Hx = curl_get_contents ('http: // www.111cn.net /');

I believe all the friends who have used the file_get_contents function know that when the obtained $ url cannot be accessed, it will lead to a long wait for the page, and even cause the PHP process to occupy 100% of the CPU, so this function was born.

Set it through default_socket_timeout in php. ini. The default timeout value is default_socket_timeout = 60.

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Max_execution_time = 30 Default_socket_timeout = 60

Suppose you use file_get_contents to spend 45 while max_execution_time is 30. Will it time out?
The answer is NO, because max_execution_time does not affect the operating system call or stream operation.
Another point to note is that default_socket_timeout is calculated before the socket response. If a response is received, it will continue to be executed.

You can set it in the following three ways:

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1 modify default_socket_timeout = 120 directly in php. ini 2 ini_set ('default _ socket_timeout ', 120 ); 3 $ strm = stream_context_create (array ( 'Http' => array ( 'Timeout' = & gt; 120         )     ) );

Curl introduction

The reason for retaining the original file_get_contents function is that it is more appropriate to use native file_get_contents when reading local files.

In addition, the optimization of file_get_contnets from the banquet can be viewed as follows:

First, run the top command to view the php-cgi process with high CPU usage.

 

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Top-10:34:18 up 724 days, 3 users, load average: 17.86, 11.16, 7.69 Task: 561 total, 15 running, 546 sleeping, 0 stopped, 0 zombie Cpu (s): 5.9% us, 4.2% sy, 0.0% ni, 89.4% id, 0.2% wa, 0.0% hi, 0.2% si, 0.0% st Mem: 8100996 k total, 4320108 k used, 3780888 k free, 772572 k buffers Swap: 8193108 k total, 50776 k used, 8142332 k free, 412088 k cached Pid user pr ni virt res shr s % CPU % mem time + COMMAND 10747 www 18 0 360 m 22 m 12 m R 100.6 0: 02. 60 php-cgi 10709 www 16 0 359 m 28 m 17 m R 96.8 0.4. 34 php-cgi 10745 www 18 0 360 m 24 m 14 m R 94.8 0.3. 51 php-cgi 10707 www 18 0 360 m 25 m 14 m S 77.4 0: 33. 48 php-cgi 10782 www 20 0 360 m 26 m 15 m R 75.5 0.3. 93 php-cgi 10708 www 25 0 360 m 22 m 12 m R 69.7 0.3. 16 php-cgi 10683 www 25 0 362 m 28 m 15 m R 54.2 0.4. 65 php-cgi 10711 www 25 0 360 m 25 m 15 m R 52.2 0.3. 25 php-cgi 10688 www 25 0 359 m 25 m 15 m R 38.7 0.3. 44 php-cgi 10719 www 25 0 360 m 26 m 16 m R 7.7 0.3. 59 php-cgi Find the PID of one of the php-cgi processes with CPU 100% and run the following command to trace the PID: Strace-p 10747

If the screen displays:

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Select (7, [6], [6], [], {15, 0}) = 1 (out [6], left {15, 0 }) Poll ([{fd = 6, events = POLLIN}], 1, 0) = 0 (Timeout) Select (7, [6], [6], [], {15, 0}) = 1 (out [6], left {15, 0 }) Poll ([{fd = 6, events = POLLIN}], 1, 0) = 0 (Timeout) Select (7, [6], [6], [], {15, 0}) = 1 (out [6], left {15, 0 }) Poll ([{fd = 6, events = POLLIN}], 1, 0) = 0 (Timeout) Select (7, [6], [6], [], {15, 0}) = 1 (out [6], left {15, 0 }) Poll ([{fd = 6, events = POLLIN}], 1, 0) = 0 (Timeout) Select (7, [6], [6], [], {15, 0}) = 1 (out [6], left {15, 0 }) Poll ([{fd = 6, events = POLLIN}], 1, 0) = 0 (Timeout) Select (7, [6], [6], [], {15, 0}) = 1 (out [6], left {15, 0 }) Poll ([{fd = 6, events = POLLIN}], 1, 0) = 0 (Timeout) Select (7, [6], [6], [], {15, 0}) = 1 (out [6], left {15, 0 }) Poll ([{fd = 6, events = POLLIN}], 1, 0) = 0 (Timeout) Select (7, [6], [6], [], {15, 0}) = 1 (out [6], left {15, 0 }) Poll ([{fd = 6, events = POLLIN}], 1, 0) = 0 (Timeout) Select (7, [6], [6], [], {15, 0}) = 1 (out [6], left {15, 0 }) Poll ([{fd = 6, events = POLLIN}], 1, 0) = 0 (Timeout) Select (7, [6], [6], [], {15, 0}) = 1 (out [6], left {15, 0 }) Poll ([{fd = 6, events = POLLIN}], 1, 0) = 0 (Timeout)

The problem is caused by file_get_contents.

Set the timeout time to solve this problem. If curl is not installed, you must use this method.

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$ Ctx = stream_context_create (array ( 'Http' => array ( 'Timeout' => 1 // set a timeout time, in seconds        )      )   ); File_get_contents ("http://www.111cn.net/", 0, $ ctx );