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SmartFinn/sym2bind.sh

Last active October 11, 2022 06:40
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  1. SmartFinn revised this gist Oct 11, 2022. 1 changed file with 0 additions and 0 deletions.
    Empty file modified sym2bind.sh
    100644 → 100755
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  2. SmartFinn created this gist Oct 20, 2021.
    163 changes: 163 additions & 0 deletions sym2bind.sh
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    #!/usr/bin/env bash
    #
    # Copyright (c) 2021 Sergei Eremenko (https://github.com/SmartFinn)
    #
    # Permission to use, copy, modify, and/or distribute this software for any
    # purpose with or without fee is hereby granted.
    #
    # THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES WITH
    # REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
    # AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT,
    # INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
    # LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR
    # OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
    # PERFORMANCE OF THIS SOFTWARE.

    set -euo pipefail

    PROGNAME="$(basename "${BASH_SOURCE[0]}")"
    VERSION="0.1.0"
    declare -i MAXDEPTH=1
    declare -i FORCE_YES=0

    usage() {
    cat <<- EOF
    This script finds symbolic links to directories and replace them with bind mount.
    USAGE
    $ $PROGNAME [-d NUM] [-f] [-v] [DIR ..]
    OPTIONS
    -d NUM limit the depth of recursion (default: 1)
    -f do not ask when adding directory
    -v print version and exit
    -h show this help
    EXAMPLES
    $ $PROGNAME # find and suggest bind mount for symlinks in the current dir
    $ $PROGNAME ~/ # find for symlinks in the HOME directory
    $ $PROGNAME -d 2 ~/ # find symlinks in the HOME dir and subdirectories
    EOF

    exit "${1:-0}"
    }

    _yes_no() {
    local msg="$1"

    [ "$FORCE_YES" -eq 1 ] && return 0

    read -r -n 1 -e -p "$msg [Y/n]: " yes_no </dev/tty # don't read from stdin

    case "$yes_no" in
    [Yy]|'') return 0 ;;
    [Nn]|*) return 1 ;;
    esac
    }

    _no_yes() {
    local msg="$1"

    read -r -n 1 -e -p "$msg [y/N]: " yes_no </dev/tty # don't read from stdin

    case "$yes_no" in
    [Yy]) return 0 ;;
    [Nn]|*) return 1 ;;
    esac
    }

    hr() {
    printf '\n%*s\n' "${COLUMNS:-$(tput cols)}" '' | tr ' ' -
    }

    while getopts ":hd:fv" opt; do
    case "$opt" in
    h)
    usage 0
    ;;
    d)
    if ! [[ $OPTARG =~ [0-9]+ ]]; then
    echo "Error: option -$opt requires a number however '$OPTARG' was passed."
    usage 2
    fi
    MAXDEPTH="$OPTARG"
    ;;
    f)
    FORCE_YES=1
    ;;
    v)
    echo "$PROGNAME v$VERSION"
    exit 0
    ;;
    :)
    echo "Error: option -$OPTARG requires an argument" >&2
    usage 2
    ;;
    \?)
    echo "Invalid option: -$OPTARG" >&2
    usage 2
    ;;
    esac
    done

    shift $((OPTIND-1))

    declare -a DIRS=()
    declare -A MOUNTPOINTS=()

    for dir in "$@"; do
    if [ ! -d "$dir" ]; then
    echo "Error: '$dir' is not a directory."
    usage 2
    fi
    DIRS+=( "$(readlink -f "$dir")" )
    done

    if [ "${#DIRS[@]}" -eq 0 ]; then
    DIRS+=( "$(readlink -f "$(pwd)")" )
    fi

    while read -d$'\n' -r symlink; do
    mpoint="$(readlink -f "$symlink")"
    [ -d "$mpoint" ] || continue
    _yes_no "Add '$symlink' -> '$mpoint' to mount list?" || continue

    MOUNTPOINTS+=(["$mpoint"]="$symlink")
    done < <(find "${DIRS[@]}" -maxdepth "$MAXDEPTH" -type l -print)

    [ "${#MOUNTPOINTS[@]}" -gt 0 ] || exit 0

    hr

    echo
    echo "The following lines will be added to /etc/fstab:"
    echo

    for mp in "${!MOUNTPOINTS[@]}"; do
    echo " $mp ${MOUNTPOINTS["$mp"]} none bind 0 0"
    done

    echo
    echo "The following symlinks will be replaced with directories:"
    echo

    for mp in "${!MOUNTPOINTS[@]}"; do
    echo " - ${MOUNTPOINTS["$mp"]}"
    done

    hr

    _no_yes "Do you confirm actions above?" || exit 0

    for dir in "${!MOUNTPOINTS[@]}"; do
    echo "$dir ${MOUNTPOINTS["$dir"]} none bind 0 0"
    done | sudo tee -a /etc/fstab >/dev/null

    for dir in "${!MOUNTPOINTS[@]}"; do
    mpoint="${MOUNTPOINTS["$dir"]}"
    [ -L "$mpoint" ] || continue

    rm -f "$mpoint"
    mkdir -p "$mpoint"
    sudo mount "$mpoint"
    done