aboutsummaryrefslogtreecommitdiffstatshomepage
path: root/update.sh
blob: d32e25484c8e6adb11636e0d8535ad53b35f903a (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
#!/usr/bin/env bash

# Copyright (c) 2016 Egor Tensin <Egor.Tensin@gmail.com>
# This file is part of the "Windows configuration files" project.
# For details, see https://github.com/egor-tensin/windows-home.
# Distributed under the MIT License.

# This script relies on the availability of native symlinks.
# Those are indeed supported by NTFS, but require Administrator privileges for
# creation.
# It likely won't bother you as long as you don't use the functions defined in
# this file.
# In any case, you will see `ln` complaining about some access being denied in
# case something goes wrong.
#
# Remember that in order to force `ln` to use native NTFS symlinks, your
# `CYGWIN` Windows environment variable value **must** include either
# `winsymlinks:native` or `winsymlinks:nativestrict`!

# usage: ./update.sh

set -o errexit
set -o nounset
set -o pipefail

dump() {
    local prefix="${FUNCNAME[0]}"

    if [ "${#FUNCNAME[@]}" -gt 1 ]; then
        prefix="${FUNCNAME[1]}"
    fi

    while [ "$#" -ne 0 ]; do
        echo "$prefix: $1" || true
        shift
    done
}

script_dir="$( cd "$( dirname "${BASH_SOURCE[0]}" )" && pwd )"
 
ensure_symlinks_enabled() {
    case "${CYGWIN:-}" in
        *winsymlinks:native*)       ;;
        *winsymlinks:nativestrict*) ;;

        *)
            dump 'native Windows symbolic links aren'"'"'t enabled in Cygwin' >&2
            return 1
            ;;
    esac
}

database_path="$script_dir/db.bin"
declare -A database

ensure_database_exists() {
    [ -f "$database_path" ] || touch "$database_path"
}

read_database() {
    local entry
    while IFS= read -d '' -r entry; do
        database[$entry]=1
    done < "$database_path"
}

write_database() {
    > "$database_path"

    local entry
    for entry in "${!database[@]}"; do
        printf '%s\0' "$entry" >> "$database_path"
    done
}

delete_obsolete_dirs() {
    if [ $# -ne 2 ]; then
        echo "usage: ${FUNCNAME[0]} BASE_DIR DIR"
        return 1
    fi

    local base_dir="$1"
    local dir="$2"

    base_dir="$( readlink -m "$base_dir" )"
    dir="$( readlink -m "$dir" )"

    if [ ! -d "$base_dir" ]; then
        dump "base directory doesn't exist: $base_dir" >&2
        return 1
    fi

    [ "$base_dir" == "$dir" ] && return 0

    local subpath="${dir##$base_dir/}"

    if [ "$subpath" == "$dir" ]; then
        dump "base directory: $base_dir"    >&2
        dump "... is not a parent of: $dir" >&2
        return 1
    fi

    ( cd "$base_dir" && rmdir -p "$subpath" --ignore-fail-on-non-empty )
}

delete_obsolete_entries() {
    local entry
    for entry in "${!database[@]}"; do
        dump "entry: $entry"

        local var_name
        var_name="$( expr "$entry" : '%\([_[:alpha:]][_[:alnum:]]*\)%/' )"

        if [ -z "$var_name" ]; then
            dump '    couldn'"'"'t extract variable name' >&2
            unset database["$entry"]
            continue
        fi

        if [ -z "${!var_name+x}" ]; then
            dump "    variable is not set: $var_name" >&2
            unset database["$entry"]
            continue
        fi

        local dest_var_dir
        dest_var_dir="$( readlink -m "$( cygpath "${!var_name}" )" )"
        local src_var_dir="$script_dir/%$var_name%"

        local subpath="${entry#%$var_name%/}"

        local dest_path="$dest_var_dir/$subpath"
        local src_path="$src_var_dir/$subpath"

        if [ ! -e "$dest_path" ]; then
            dump "    missing destination file: $dest_path" >&2
            unset database["$entry"]
            continue
        fi

        if [ ! -e "$src_path" ]; then
            dump "    missing source file: $src_path" >&2
            rm -f "$dest_path"
            unset database["$entry"]

            local dest_dir
            dest_dir="$( dirname "$dest_path" )"

            delete_obsolete_dirs "$dest_var_dir" "$dest_dir" || true
            continue
        fi

        if [ ! -L "$dest_path" ]; then
            dump "    not a symbolic link: $dest_path" >&2
            unset database["$entry"]
            continue
        fi

        local target_path
        target_path="$( readlink -e "$dest_path" )"

        if [ "$target_path" != "$src_path" ]; then
            dump "    points to a wrong file: $dest_path" >&2
            unset database["$entry"]
            continue
        fi

        dump '    ... points to the right file'
    done
}

var_name_regex='%\([_[:alpha:]][_[:alnum:]]*\)%'

discover_new_entries() {
    local src_var_dir
    while IFS= read -d '' -r src_var_dir; do
        dump "source directory: $src_var_dir"

        local var_name
        var_name="$( basename "$src_var_dir" )"
        var_name="$( expr "$var_name" : "$var_name_regex" )"
        dump "    variable name: $var_name"

        if [ -z "${!var_name+x}" ]; then
            dump "    variable is not set: $var_name" >&2
            continue
        fi

        local dest_var_dir
        dest_var_dir="$( readlink -m "$( cygpath "${!var_name}" )" )"
        dump "    destination directory: $dest_var_dir"

        local src_path
        while IFS= read -d '' -r src_path; do
            dump "        source file: $src_path"

            local entry="%$var_name%${src_path:${#src_var_dir}}"

            if [ -n "${database[$entry]+x}" ]; then
                dump '        ... points to the right file'
                continue
            fi

            local dest_path="$dest_var_dir${src_path:${#src_var_dir}}"
            dump "        destination file: $dest_path"

            mkdir -p "$( dirname "$dest_path" )"
            ln --force -s "$src_path" "$dest_path"

            database[$entry]=1
        done < <( find "$src_var_dir" -type f -print0 )

    done < <( find "$script_dir" -regextype posix-basic -mindepth 1 -maxdepth 1 -type d -regex ".*/$var_name_regex\$" -print0 )
}

main() {
    ensure_database_exists
    read_database
    delete_obsolete_entries
    ensure_symlinks_enabled
    discover_new_entries
    write_database
}

main