mount-ram.sh

#!/bin/sh

# This program has two feature.
#
# 1. Create a disk image on RAM.
# 2. Mount that disk image.
#
# Usage:
#   $0 <dir> <size> <name>
#
#   size:
#     The `size' is a size of disk image (MB).
#
#   dir:
#     The `dir' is a directory, the dir is used to mount the disk image.
#
#   name:
#     The volume name of the mounted disk image.
#
# See also:
#   - hdid(8)
#
# Mounting at system boot:
#   - Terminal > $ export VISUAL=nano && crontab -e
#   - Add "@reboot /path/to/mount-ram.sh <dir> <size> <name>
#

if [ $# -lt 1 ]; then
    cat <<EOF >&2
Usage: $0 <dir> [size]
Creates a disk image of the given size in megabyte (default: 64) and mounts it at the given directory.
EOF
    exit 1
fi
 
mount_point=${1}
size=${2:-64}
volume_name=${3:-ramdisk}

mkdir -p $mount_point
if [ $? -ne 0 ]; then
    echo "The mount point isn't available." >&2
    exit $?
fi
 
sector=$(expr $size \* 1024 \* 1024 / 512)
device_name=$(hdid -nomount "ram://${sector}" | awk '{print $1}')
if [ $? -ne 0 ]; then
    echo "Could not create disk image." >&2
    exit $?
fi
 
newfs_hfs -v $volume_name $device_name > /dev/null
if [ $? -ne 0 ]; then
    echo "Could not format disk image." >&2
    hdiutil detach -quiet $device_name
    exit $?
fi
 
mount -t hfs $device_name $mount_point
if [ $? -ne 0 ]; then
    echo "Could not mount disk image." >&2
    hdiutil detach -quiet $device_name
    exit $?
fi

#Like having a default temp dir in it
mkdir -p $mount_point/temp

umount-ram.sh

#!/bin/sh

# This program has two features.
#
# 1. Unmount a disk image.
# 2. Detach the disk image from RAM.
#
# Usage:
#   $0 <dir>
#
#   dir:
#     The `dir' is a directory, the dir is mounting a disk image.
#
# See also:
#   - hdid(8)
#

mount_point=$1
if [ ! -d "${mount_point}" ]; then
    echo "The mount point didn't available." >&2
    exit 1
fi
mount_point=$(cd $mount_point && pwd)

device_name=$(df "${mount_point}" 2>/dev/null | tail -1 | grep "${mount_point}" | cut -d' ' -f1)
if [ -z "${device_name}" ]; then
    echo "The mount point didn't mount disk image." >&2
    exit 1
fi

umount "${mount_point}"
if [ $? -ne 0 ]; then
    echo "Could not unmount." >&2
    exit $?
fi

hdiutil detach -quiet $device_name