The catch is that you always have to return something, even if that something is "nothing". Some sites feature a waiting page which refreshes frequently, waiting on output from something. It might feature a pleasant animated GIF, and hopefully not something along the lines of WAIT with the horrific <BLINK> tag.

A quick way of doing this is to create script A which, when run the first time will fork off script B, and then refresh to itself with a special parameter. Script B will write to a certain filename in /tmp, for example, and script A, when called, will check for this file. When this file is there, script A prints it, possibly deletes it, and stops refreshing. The name of the file is encoded in the special parameter. If, for example, the parameter "_" was set to "fZdaPXzAQ", then you would be waiting for the file "/tmp/fZdaPXzAQ.out". The choice of name is arbitrary.

There are a couple of things you will want to note:
  1. You might want to write a separate program to clean out any stale /tmp entries instead of leaving this up to script A. This way the user can reload the page and still get output, without you having to process all over again.
  2. Your script B should not write directly to the /tmp file, but should create a preliminary version which it writes to, then renames it at the end to the proper name. This will prevent script A from jumping the gun and printing when script B has only written half its output.

In reply to Re: executing other scripts while printing a webpage by tadman
in thread executing other scripts while printing a webpage by Scott203

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