Whole document tree
    

Whole document tree

11.2.9 Common problems and solutions

11.2.9 Common problems and solutions

  • 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.

  • Check the installation instructions above.

  • Check the HTTP server's log files. ("tail -f logfile" in a separate window may be useful!)

  • Always check a script for syntax errors first, by doing something like "python script.py".

  • When using any of the debugging techniques, don't forget to add "import sys" to the top of the script.

  • When invoking external programs, make sure they can be found. Usually, this means using absolute path names -- PATH is usually not set to a very useful value in a CGI script.

  • When reading or writing external files, make sure they can be read or written by every user on the system.

  • 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.
See About this document... for information on suggesting changes.