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<H2><A NAME="SECTION00132100000000000000000">
11.2.10 Common problems and solutions</A>
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<LI>Most HTTP servers buffer the output from CGI scripts until the
script is completed. This means that it is not possible to display a
progress report on the client's display while the script is running.
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</LI>
<LI>Check the installation instructions above.
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<LI>Check the HTTP server's log files. ("<tt class="samp">tail -f logfile</tt>" in a
separate window may be useful!)
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<LI>Always check a script for syntax errors first, by doing something
like "<tt class="samp">python script.py</tt>".
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<LI>If your script does not have any syntax errors, try adding
"<tt class="samp">import cgitb; cgitb.enable()</tt>" to the top of the script.
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<LI>When invoking external programs, make sure they can be found.
Usually, this means using absolute path names -- <a class="envvar" id='l2h-2976'>PATH</a> is
usually not set to a very useful value in a CGI script.
<P>
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<LI>When reading or writing external files, make sure they can be read
or written by the userid under which your CGI script will be running:
this is typically the userid under which the web server is running, or some
explicitly specified userid for a web server's "<tt class="samp">suexec</tt>" feature.
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<LI>Don't try to give a CGI script a set-uid mode. This doesn't work on
most systems, and is a security liability as well.
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<span class="release-info">Release 2.3.4, documentation updated on May 20, 2004.</span>
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