无法使用php exec函数执行nutch crawl命令

Question

I have to run Nutch crawl commands using php exec but it shows

"0 Error: JAVA_HOME is not set"

The command works fine with terminal. I have tried the below code in crawl.php where apache-nutch-1.15 directory is placed.

exec('apache-nutch-1.15/bin/nutch inject crawl/crawldb urls',$output);

and this gives the above mentioned error.

Thank you in advance for any assistance you can provide.

Answer 1

In order to run Nutch you need the JAVA_HOME environment variable set and pointing to the proper path (where your JVM is installed). This works on your terminal because you have this variable set already. You can check this with:

$ env | grep JAVA

When a new process is started with exec from PHP, this environment variable is not set because it is not a shell, you're only starting a process without any "shell environment". You can use the putenv function to specify some environment variables before calling exec.