04-01-2008
PGM=${0##/}
TMP=/tmp/${PGM}.$$
$0 is the complete-name-of-the-script in side the script (e.g. /home/mydir/myscript.sh)
So, ${0##/} means the complete-name-of-the-script without the starting-slash (if it exists)!!
But, what I thing you wanted to write is:
PGM=${0##*/}
which means complete-name-of-the-script without everthing up to and including the last-slash (e.g. myscript.sh)
Then, $$ is the Process-ID of the current script. So, TMP will be set to be /tmp/myscript.sh.1234 (where 1234 is the process-id).
This combination is normally used to create unique (i.e. different for each running script) names.
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LEARN ABOUT DEBIAN
speedy_backend
SPEEDY_BACKEND(1p) SPEEDY_BACKEND(1p)
NAME
speedy_backend - the backend process for a persistent Perl interpreter
SYNOPSIS
none ; this program is not meant to be called directly.
DESCRIPTION
speedy, short for SpeedyCGI, is a way to run perl scripts persistently, which can make them run much more quickly.
After the script is initially run, instead of exiting, the perl interpreter is kept running inside a backend process, speedy_backend. Dur-
ing subsequent runs, this interpreter is used to handle new executions instead of starting a new perl interpreter each time. A very fast
frontend program, speedy, written in C, is executed for each request. This fast frontend then contacts the persistent Perl process, which
is usually already running, to do the work and return the results.
Each perl script runs in its own Unix process, so one perl script can't interfere with another. Command line options can also be used to
deal with programs that have memory leaks or other problems that might keep them from otherwise running persistently.
The speedy front end connects to the back end process, speedy_backend, via a Unix socket in /tmp. A queue is kept in a shared file in /tmp
that holds an entry for each process. In that queue are the pids of the perl processes waiting for connections. The frontend pulls a
process out of this queue, connects to its socket, sends over the environment and argv, and then uses this socket for stdin/stdout to the
perl process.
FILES
/tmp/speedy* A unix socket used to connect to the frontend process.
AUTHOR
Sam Horrocks
http://daemoninc.com
sam@daemoninc.com
NOTES
This manual page was created by Niko Tyni <ntyni@iki.fi> for Debian GNU/Linux, because the original program does not have one. It is based
on the original and more complete CGI::SpeedyCGI(3pm) manual page.
SEE ALSO
perl(1), CGI::SpeedyCGI(3pm), speedy(1)
SPEEDY_BACKEND(1p)