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Diffstat (limited to 'update.sh')
| -rw-r--r-- | update.sh | 216 |
1 files changed, 216 insertions, 0 deletions
diff --git a/update.sh b/update.sh new file mode 100644 index 0000000..8ea0e96 --- /dev/null +++ b/update.sh @@ -0,0 +1,216 @@ +#!/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 |