pseudo mutual exclusion script

:Release Notes:
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:Detailed Notes:
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:Testing Performed:
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:QA Notes:
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:Issues Addressed:
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.gitignore

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+.*journal
+.*lastused

mutex_access.sh

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+#!/bin/bash
+set -e
+
+port=22  # default SSH port
+cache=".maccess-lastused"
+journal=".maccess-journal"
+user_host=""
+user="default"
+jump=""
+lock_file="lock.mutex"
+
+usage() {
+    echo "Usage: $0 [-p PORT -J jump1,jump2] user@host"
+    exit 1
+}
+
+# Parse command line options
+while getopts ":p:J:u:" opt; do
+    case $opt in
+        p) 
+            if ! [[ "$OPTARG" =~ ^[0-9]+$ ]] || [ "$OPTARG" -gt 65535 ]; then
+                echo "Invalid port number: $OPTARG"
+                exit 1
+            fi
+            port="$OPTARG"
+            ;;
+	    J)
+            jump="-J $OPTARG"
+            echo "ProxyJump: $jump"
+            ;;
+        u)
+            user="$OPTARG"
+            ;;
+        \?)
+            echo "Invalid option: -$OPTARG"
+            usage
+            ;;
+        :)
+            echo "Option -$OPTARG requires an argument"
+            exit 1
+            ;;
+    esac
+done
+shift $((OPTIND -1))
+
+if [ $# -ne 1 ]; then 
+    echo "Using $cache"
+
+    if [ -f "$cache" ]; then
+        {
+            read -r jump_cached
+            read -r port_cached
+            read -r user_host_cached
+        } < "$cache"
+        jump="$jump_cached"
+        port="$port_cached"
+        user_host="$user_host_cached"
+    else
+        echo "Error: Cache file $cache not found." >&2
+        usage
+    fi
+else
+    user_host="$1"   
+    echo "$jump" > "$cache"
+    echo "$port" >> "$cache"
+    echo "$user_host" >> "$cache"   
+fi
+
+
+# Check if lock file exists on remote
+if ssh $jump -p "$port" "$user_host" "test -e '$lock_file'"; then
+    echo "Error: Lock file $lock_file exists on $user_host" >&2
+    whoisusing=$(ssh $jump -p $port $user_host "cat $lock_file")
+    echo "At the moment in use by $whoisusing" >&2
+    echo "Session might be active. Exiting." >&2
+    exit 1
+fi
+
+# Create lock file
+ssh $jump -p "$port" "$user_host" "echo '$user' > '$lock_file'"
+echo "Locked for user $user"
+echo "[Start] [$(date +%Y-%m-%d-%H-%M-%S)] $user" >> $journal
+cleanup() {
+    echo "Removing lock file..."
+    ssh $jump -p "$port" "$user_host" "rm -f '$lock_file'"
+    echo "[End] [$(date +%Y-%m-%d-%H-%M-%S)] $user" >> $journal
+}
+
+# Register cleanup trap
+trap cleanup EXIT INT TERM
+
+# Start interactive session
+echo "Starting SSH session (port $port). Lock file created."
+ssh $jump -p "$port" "$user_host"
+