monitor circmsg circulation override file for changes -- email just the changes

monitor-circmsg.sh

#!/bin/bash

# Define file paths
CURRENT_FILE="/iiidb/errlog/circmsg"
PREVIOUS_FILE="/tmp/errlog-circmsg-prev"

# Check if the previous file snapshot exists
if [ ! -f "$PREVIOUS_FILE" ]; then
    # If not, create it and exit, as we can't compare yet
    cp "$CURRENT_FILE" "$PREVIOUS_FILE"
    exit 0
fi

# Compute checksums
CURRENT_CHECKSUM=$(md5sum "$CURRENT_FILE" | awk '{print $1}')
PREVIOUS_CHECKSUM=$(md5sum "$PREVIOUS_FILE" | awk '{print $1}')

# Compare checksums to see if the file has changed
if [ "$CURRENT_CHECKSUM" != "$PREVIOUS_CHECKSUM" ]; then
    # Use diff to capture changes
    DIFF_OUTPUT=$(diff "$PREVIOUS_FILE" "$CURRENT_FILE")

    # Parse the diffs (implement your parsing logic here)
    # PARSED_DIFFS=$(echo "$DIFF_OUTPUT" | your_parsing_command_here)

    # For the sake of example, let's just assign DIFF_OUTPUT to PARSED_DIFFS
    PARSED_DIFFS="$DIFF_OUTPUT"

    # Check if there are any diffs to send
    if [ -n "$PARSED_DIFFS" ]; then
        # Send an email with the parsed diffs
        # Replace the next line with your email command
        echo "$PARSED_DIFFS" | mail -s "`circmsg` File Changes Detected" ilshelp@chpl.org
    fi

    # Update the previous file snapshot for next comparison
    cp "$CURRENT_FILE" "$PREVIOUS_FILE"
else
    echo "No changes detected."
fi