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-rw-r--r--src/vars.sh58
1 files changed, 58 insertions, 0 deletions
diff --git a/src/vars.sh b/src/vars.sh
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+# Copyright (c) 2016 Egor Tensin <Egor.Tensin@gmail.com>
+# This file is part of the "Configuration file sharing" project.
+# For details, see https://github.com/egor-tensin/config-links.
+# Distributed under the MIT License.
+
+# Variable resolution
+
+declare -A cached_paths
+
+resolve_variable() {
+ if [ "$#" -ne 1 ]; then
+ echo "usage: ${FUNCNAME[0]} VAR_NAME" >&2
+ return 1
+ fi
+
+ local var_name="$1"
+
+ if [ -n "${cached_paths[$var_name]+x}" ]; then
+ echo "${cached_paths[$var_name]}"
+ return 0
+ fi
+
+ if [ "$var_name" = "$root_var_name" ]; then
+ echo ''
+ return 0
+ fi
+
+ if [ -z "${!var_name+x}" ]; then
+ dump "variable is not set: $var_name" >&2
+ return 1
+ fi
+
+ local var_path="${!var_name}"
+ traverse_path --exist --directory -- "$var_path"
+}
+
+cache_variable() {
+ local var_name
+ for var_name; do
+ [ -n "${cached_paths[$var_name]+x}" ] && continue
+ cached_paths[$var_name]="$( resolve_variable "$var_name" )"
+ done
+}
+
+readonly root_var_name='CONFIG_LINKS_ROOT'
+readonly var_name_regex='%\([_[:alpha:]][_[:alnum:]]*\)%'
+
+extract_variable_name() {
+ local s
+ for s; do
+ local var_name
+ if ! var_name="$( expr "$s" : "$var_name_regex/" )"; then
+ dump "couldn't extract variable name from: $s" >&2
+ return 1
+ fi
+ echo "$var_name"
+ done
+}