wget适用于命令行，但不适用于PHP

Question

I'm trying to access some remote web sites within my PHP script, but the script keeps timing out.

It only fails when run on the test web server, but not on the production web server.

The script works just fine when accessing most other URLs, eg stackoverflow.com, or www.google.com.

I've tried it with the PHP commands file_get_contents($url) , as well as exec("wget $url" ) and exec("curl $url") , all of which fail. Again, most sites work fine, just not the ones I actually want.

I can access the remote sites on the command-line via wget and curl. Even the PHP script works from the command-line! So I know the script works.

The script works when run on our production web server. But it doesn't work when it runs on the test web server.

It appears that there is something peculiar about a GET request from the test server to the remote sites only when comes from Apache, but not the command-line.

How do I diagnose this problem?

Answer 1

Here are a few things to consider:

• Different system users for command line and web server.
• Proxy server configuration (sometimes done via environment variables).
• Different network (DNS, routing, firewall, etc) configurations for test and production servers.