62 lines
2 KiB
Bash
Executable file
62 lines
2 KiB
Bash
Executable file
#!/bin/sh
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##
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# This software was developed and / or modified by Raytheon Company,
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# pursuant to Contract DG133W-05-CQ-1067 with the US Government.
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#
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# U.S. EXPORT CONTROLLED TECHNICAL DATA
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# This software product contains export-restricted data whose
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# export/transfer/disclosure is restricted by U.S. law. Dissemination
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# to non-U.S. persons whether in the United States or abroad requires
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# an export license or other authorization.
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#
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# Contractor Name: Raytheon Company
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# Contractor Address: 6825 Pine Street, Suite 340
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# Mail Stop B8
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# Omaha, NE 68106
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# 402.291.0100
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#
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# See the AWIPS II Master Rights File ("Master Rights File.pdf") for
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# further licensing information.
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##
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# SOFTWARE HISTORY
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# Date Ticket# Engineer Description
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# ------------ ---------- ----------- --------------------------
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# Feb 16, 2008 jelkins - Initial creation
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# waits until the program is not in use before executing it
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# USAGE
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# Create a link to this script. The link name should be the name of the program
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# to execute as a single instance and should be placed into a directory located
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# one directory above the location of the actual program.
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lockfile="/tmp/$(basename $0).tmp.lock"
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program_location=($(which -a $(basename $0)))
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# critical section checking
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# http://www.davidpashley.com/articles/writing-robust-shell-scripts.html
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while [ 1 ]
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do
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if ( set -o noclobber; echo "$USER on PID $$" > "$lockfile") 2> /dev/null;
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then
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trap 'rm -f "$lockfile"' INT TERM EXIT
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${program_location[1]} $@
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error_code=$?
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rm -f "$lockfile"
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trap - INT TERM EXIT
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exit $error_code
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else
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lock_id="$(cat $lockfile)"
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if [ ! "$lock_id" = "$prev_lock_id" ]
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then
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echo "Failed to acquire lockfile: $lockfile."
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echo "Held by $lock_id"
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echo "Waiting to acquire lockfile ..."
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prev_lock_id="$lock_id"
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fi
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fi
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done
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