initial commit

1 files changed, 216 insertions, 0 deletions

diff --git a/update.sh b/update.sh
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+++ b/update.sh
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+#!/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 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`!
+
+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 "${CYGWIN:-}" in
+        *winsymlinks:native*)       ;;
+        *winsymlinks:nativestrict*) ;;
+
+        *)
+            dump "native Windows symlinks aren't enabled in Cygwin" >&2
+            return 1
+            ;;
+    esac
+}
+
+database_path="$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
+}
+
+clean_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 "$subpath" --ignore-fail-on-non-empty )
+}
+
+purge_obsolete_entries() {
+    local entry
+    for entry in "${!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 "$dest_path" )"
+
+            clean_dirs "$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
+    done
+}
+
+add_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" : '%\([_[:alpha:]][_[:alnum:]]*\)%' )"
+        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}}"
+
+            [ -n "${database[$entry]+x}" ] && continue
+
+            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-extended -mindepth 1 -maxdepth 1 -type d -regex '.*/%[_[:alpha:]][_[:alnum:]]*%$' -print0 )
+}
+
+main() {
+    ensure_database_exists
+    read_database
+    purge_obsolete_entries
+    ensure_symlinks_enabled
+    add_new_entries
+    write_database
+}
+
+main