Serve *.tar as RAM disk

mac_ramdisk.sh

#!/bin/bash

# Path to the tar archive
TarPath="$1"

# Ensure a tar path is provided
if [[ -z "$TarPath" || ! -f "$TarPath" ]]; then
    echo "Usage: $0 <path_to_tar>"
    exit 1
fi

# Extract the basename of the tar file and remove the .tar extension for the RAM disk name
RamDiskName=$(basename "$TarPath" .tar)

# Step 1: Measure the size of the tar file using du
# -k option makes du report size in kilobytes
SizeInKB=$(du -k "$TarPath" | cut -f1)
SizeInMB=$((SizeInKB / 1024))

# Add a small buffer to account for filesystem overhead and tar metadata
# This is a rough estimation; adjust the buffer size as needed
BufferMB=10
TotalSizeMB=$((SizeInMB + BufferMB))

# Convert size to blocks (512 bytes per block)
SizeInBlocks=$((TotalSizeMB * 2048))

# Step 2: Create and mount a RAM disk
echo "Creating a RAM disk named '$RamDiskName' of size ${TotalSizeMB}MB..."
DiskInfo=$(hdiutil attach -nomount ram://$SizeInBlocks)
Device=$(echo "$DiskInfo" | cut -f 1)

# Step 3: Format the RAM disk (HFS+ format)
echo "Formatting the RAM disk..."
diskutil eraseVolume HFS+ "$RamDiskName" $Device

# Step 4: Extract the tar archive into the RAM disk
echo "Extracting the tar archive to the RAM disk..."
tar -xf "$TarPath" -C /Volumes/"$RamDiskName"

echo "Tar contents are now available in /Volumes/$RamDiskName"

# Cleanup function to detach the RAM disk when done
cleanup() {
    echo "Detaching RAM disk '$RamDiskName'..."
    hdiutil detach $Device
}

# Trap script exit for cleanup
trap cleanup EXIT

# Keep the script running until manually stopped to keep the RAM disk mounted
echo "Press Ctrl+C to detach the RAM disk and exit..."
while true; do sleep 1; done