gistfile1.txt

#!/bin/bash

# Function to display help message
show_help() {
    echo "Usage: $0 [OPTION]... [FILE]"
    echo "Set up and mount loop devices for a given file, create new files of specified or random size and mount them, or create a ramdisk of specified size and mount it."
    echo ""
    echo "  --help                 display this help and exit"
    echo "  automount <Size>       automatically create a file of specified size, set up and mount it."
    echo "  polymount <Size> <N>   create N files of specified size, set up and mount them."
    echo "  polymount rand <N> <MinSize> <MaxSize>  create N files with random sizes between MinSize and MaxSize, set up and mount them."
    echo "  tmpfsmount <N> <Size>  create and mount N ramdisks of specified size as loop devices."
    echo "  <FilePath>             path to the existing file to set up and mount"
    echo ""
    echo "Examples:"
    echo "  $0 /path/to/your/file.img                 Set up an existing file as a loop device."
    echo "  $0 automount 1M                           Create a 1M-sized file and set it up as a loop device."
    echo "  $0 polymount 1M 5                         Create 5 1M-sized files and set them up as loop devices."
    echo "  $0 polymount rand 3 10M 100M              Create 3 files with random sizes between 10M and 100M, and set them up as loop devices."
    echo "  $0 tmpfsmount 4 1G                        Create 4 1G ramdisks and set them up as loop devices."
    echo ""
    echo "Note: Run this script with root permissions or using sudo."
}

# Other function definitions remain unchanged

# New function to create and mount multiple ramdisks as loop devices
tmpfsmount() {
    N=$2
    RAMDISK_SIZE=$3
    SIZE_VALUE=$(echo $RAMDISK_SIZE | sed -E 's/[^0-9]//g')
    SIZE_UNIT=$(echo $RAMDISK_SIZE | sed -E 's/[0-9]//g' | tr '[a-z]' '[A-Z]')

    case $SIZE_UNIT in
        G) BYTE_SIZE=$(($SIZE_VALUE * 1024 * 1024 * 1024)) ;;
        M) BYTE_SIZE=$(($SIZE_VALUE * 1024 * 1024)) ;;
        *) echo "Unknown size unit: $SIZE_UNIT" >&2; exit 1 ;;
    esac

    for ((i=1; i<=$N; i++)); do
        TMPDIR=$(mktemp -d)
        if [ ! -d "$TMPDIR" ]; then
            echo "Failed to create temporary directory."
            continue
        fi

        sudo mount -t tmpfs -o size=$BYTE_SIZE tmpfs $TMPDIR
        echo "Ramdisk $i mounted at $TMPDIR"

        FILEPATH="${TMPDIR}/ramdisk$i.img"
        dd if=/dev/zero of="$FILEPATH" bs=1$SIZE_UNIT count=$SIZE_VALUE status=progress
        setup_and_mount "$FILEPATH"
    done
}

# Function to automatically create a file of a specified size and set up and mount it as a loop device
automount() {
    GUID=$(uuidgen) # Generate a unique identifier for the filename
    FILENAME="${GUID}.img" # Create a filename with the .img extension
    FILEPATH="/tmp/${FILENAME}" # Define the full path in /tmp directory
    FILESIZE=$1 # The size of the file to be created, passed as an argument

    # Extract the numeric value and the unit (G,M) from the file size argument
    SIZE_VALUE=$(echo $FILESIZE | sed -E 's/[^0-9]//g')
    SIZE_UNIT=$(echo $FILESIZE | sed -E 's/[0-9]//g')

    # Create a file of specified size using dd
    dd if=/dev/zero of="$FILEPATH" bs=1$SIZE_UNIT count=$SIZE_VALUE status=progress

    # Call function to set up and mount the file as a loop device
    setup_and_mount "$FILEPATH"
}

# Convert size specification to bytes
convert_size_to_bytes() {
    SIZE=$1
    NUMBER=$(echo $SIZE | sed -E 's/[^0-9]//g')
    UNIT=$(echo $SIZE | sed -E 's/[0-9]//g' | tr '[a-z]' '[A-Z]')

    case $UNIT in
        G) BYTE_SIZE=$(($NUMBER * 1024 * 1024 * 1024)) ;;
        M) BYTE_SIZE=$(($NUMBER * 1024 * 1024)) ;;
        *) echo "Unknown size unit: $UNIT" >&2; exit 1 ;;
    esac

    echo $BYTE_SIZE
}

# Generate a random size within specified range
generate_random_size() {
    MIN_SIZE_BYTES=$1
    MAX_SIZE_BYTES=$2
    RANGE=$(($MAX_SIZE_BYTES - $MIN_SIZE_BYTES + 1))

    RANDOM_BYTES=$(awk -v min=$MIN_SIZE_BYTES -v range=$RANGE 'BEGIN{srand(); print int(min+rand()*range)}')

    echo $RANDOM_BYTES
}

# Create and mount loop devices with files of specified or random sizes
polymount() {
    N=$1
    SIZE_TYPE=$2
    declare -a LOOPDEVICES
    declare -a FILEPATHS

    if [ "$SIZE_TYPE" == "rand" ]; then
        MIN_SIZE=$(convert_size_to_bytes $3)
        MAX_SIZE=$(convert_size_to_bytes $4)
    fi

    for ((i=1; i<=N; i++)); do
        if [ "$SIZE_TYPE" == "rand" ]; then
            SIZE_BYTES=$(generate_random_size $MIN_SIZE $MAX_SIZE)
            SIZE_VALUE_MB=$(($SIZE_BYTES / 1024 / 1024))
            FILESIZE="${SIZE_VALUE_MB}M"
        else {
            SIZE_VALUE_MB=$(echo $SIZE_TYPE | sed -E 's/[^0-9]//g')
            FILESIZE="${SIZE_VALUE_MB}M"
        fi
        
        GUID=$(uuidgen)
        FILENAME="${GUID}.img"
        FILEPATH="/tmp/${FILENAME}"

        dd if=/dev/zero of="$FILEPATH" bs=1M count=$SIZE_VALUE_MB status=progress

        LOOPDEVICE=$(sudo losetup -fP --show "$FILEPATH")
        if [ -z "$LOOPDEVICE" ]; then
            echo "Error creating loop device for $FILEPATH."
            continue
        fi
        echo "Loop device set up: $LOOPDEVICE"

        LOOPDEVICES+=("$LOOPDEVICE")
        FILEPATHS+=("$FILEPATH")
    done

    echo "All loop devices set up. Press [Enter] to detach all loop devices."
    read

    for LOOPDEVICE in "${LOOPDEVICES[@]}"; do
        sudo losetup -d "$LOOPDEVICE"
        echo "Loop device detached: $LOOPDEVICE"
    done

    for FILEPATH in "${FILEPATHS[@]}"; do
        rm -f "$FILEPATH"
        echo "Temporary file deleted: $FILEPATH"
    done
}

# Function to set up and mount the loop device
setup_and_mount() {
    FILEPATH="$1"

    LOOPDEVICE=$(sudo losetup -fP --show "$FILEPATH")
    if [ -z "$LOOPDEVICE" ]; then
        echo "Error creating the loop device."
        exit 1
    fi
    echo "Loop device set up: $LOOPDEVICE"

    read -p "Press [Enter] to detach the loop device."

    cleanup "$LOOPDEVICE" "$FILEPATH"
}

# Function for cleanup: detaching the loop device, and deleting the file
cleanup() {
    LOOPDEVICE=$1
    FILEPATH=$2

    sudo losetup -d "$LOOPDEVICE"
    echo "Loop device detached: $LOOPDEVICE"

    if [[ "$FILEPATH" == /tmp/*.img ]]; then
        rm -f "$FILEPATH"
        echo "Temporary file deleted: $FILEPATH"
    fi
}

# Main logic
case "$1" in
    --help)
        show_help
        ;;
    automount)
        if [ "$#" -ne 2 ]; then
            echo "Usage: $0 automount <Size>"
            exit 1
        fi
        automount $2
        ;;
    polymount)
        if [ "$2" == "rand" ] && [ "$#" -ne 5 ]; then
            echo "Usage: $0 polymount rand <N> <MinSize> <MaxSize>"
            exit 1
        elif [ "$#" -ne 3 ] && [ "$2" != "rand" ]; then
            echo "Usage: $0 polymount <Size> <N>"
            exit 1
        fi
        polymount $3 $2 $4 $5
        ;;
    tmpfsmount)
        if [ "$#" -ne 3 ]; then
            echo "Usage: $0 tmpfsmount <N> <Size>"
            exit 1
        fi
        tmpfsmount $2 $3
        ;;
    *)
        if [ "$#" -ne 1 ]; then
            show_help
            exit 1
        fi
        setup_and_mount $1
        ;;
esac