1 ################################################################################
2 # Stash/unstash support for per-directory variables
4 # Adopted for zsh-autoenv.
6 # Copyright (c) 2009,2012 Dave Olszewski <cxreg@pobox.com>
7 # http://github.com/cxreg/smartcd
9 # This code is released under GPL v2 and the Artistic License, and
10 # may be redistributed under the terms of either.
13 # This library allows you to save the current value of a given environment
14 # variable in a temporary location, so that you can modify it, and then
15 # later restore its original value.
17 # Note that you will need to be in the same directory you were in when you
18 # stashed in order to successfully unstash. This is because the temporary
19 # variable is derived from your current working directory's path.
23 # export PATH=/something/else
27 # Note that this was written for use with, and works very well with,
28 # smartcd. See the documentation there for examples.
30 # An alternate usage is `autostash' which will trigger autounstash when
31 # leaving the directory, if combined with smartcd. This reduces the amount
32 # of explicit configuration you need to provide:
35 # export PATH=/something/else
37 # You may also do both operations in one line, resulting in the very succinct
39 # autostash PATH=/something/else
41 # If you attempt to stash the same value twice, a warning will be displayed
42 # and the second stash will not occur. To make it happen anyway, pass -f
43 # as the first argument to stash.
47 # You have already stashed FOO, please specify "-f" if you want to overwrite another stashed value.
51 # This rule is a bit different if you are assigning a value and the variable
52 # has already been stashed. In that case, the new value will be assigned, but
53 # the stash will not be overwritten. This allows for non-conflicting chained
56 ################################################################################
59 if [[ $1 == "-f" ]]; then
64 if [[ $1 == "alias" && $2 == *=* ]]; then
66 local _stashing_alias_assign=1
70 local stash_expression=$1
71 local stash_which=${stash_expression%%'='*}
72 local stash_name=$(_mangle_var $stash_which)
74 # Extract the value and make it double-quote safe
75 local stash_value=${stash_expression#*'='}
76 stash_value=${stash_value//\\/\\\\}
77 stash_value=${stash_value//\"/\\\"}
78 stash_value=${stash_value//\`/\\\`}
79 stash_value=${stash_value//\$/\\\$}
81 if [[ ( -n "$(eval echo '$__varstash_alias__'$stash_name)" ||
82 -n "$(eval echo '$__varstash_function__'$stash_name)" ||
83 -n "$(eval echo '$__varstash_array__'$stash_name)" ||
84 -n "$(eval echo '$__varstash_export__'$stash_name)" ||
85 -n "$(eval echo '$__varstash_variable__'$stash_name)" ||
86 -n "$(eval echo '$__varstash_nostash__'$stash_name)" )
89 if [[ -z $already_stashed && ${already_stashed-_} == "_" ]]; then
90 local already_stashed=1
95 if [[ $stash_which == $stash_expression ]]; then
96 if [[ -z $run_from_smartcd ]]; then
97 echo "You have already stashed $stash_which, please specify \"-f\" if you want to overwrite another stashed value."
100 # Skip remaining work if we're not doing an assignment
106 # Handle any alias that may exist under this name
107 if [[ -z $already_stashed ]]; then
108 local alias_def="$(eval alias $stash_which 2>/dev/null)"
109 if [[ -n $alias_def ]]; then
110 alias_def=${alias_def#alias }
111 eval "__varstash_alias__$stash_name=\"$alias_def\""
115 if [[ $stash_which != $stash_expression && -n $_stashing_alias_assign ]]; then
116 eval "alias $stash_which=\"$stash_value\""
119 # Handle any function that may exist under this name
120 if [[ -z $already_stashed ]]; then
121 local function_def="$(declare -f $stash_which)"
122 if [[ -n $function_def ]]; then
123 # make function definition quote-safe. because we are going to evaluate the
124 # source with "echo -e", we need to double-escape the backslashes (so 1 -> 4)
125 function_def=${function_def//\\/\\\\\\\\}
126 function_def=${function_def//\"/\\\"}
127 function_def=${function_def//\`/\\\`}
128 function_def=${function_def//\$/\\\$}
129 eval "__varstash_function__$stash_name=\"$function_def\""
134 # Handle any variable that may exist under this name
135 local vartype="$(declare -p $stash_which 2>/dev/null)"
136 if [[ -n $vartype ]]; then
137 if [[ $vartype == 'typeset -a'* ]]; then
138 # varible is an array
139 if [[ -z $already_stashed ]]; then
140 eval "__varstash_array__$stash_name=(\"\${$stash_which""[@]}\")"
143 elif [[ $vartype == "export "* || $vartype == 'typeset -x'* ]]; then
144 # variable is exported
145 if [[ -z $already_stashed ]]; then
146 eval "export __varstash_export__$stash_name=\"\$$stash_which\""
148 if [[ $stash_which != $stash_expression && -z $_stashing_alias_assign ]]; then
149 eval "export $stash_which=\"$stash_value\""
153 if [[ -z $already_stashed ]]; then
154 eval "__varstash_variable__$stash_name=\"\$$stash_which\""
156 if [[ $stash_which != $stash_expression && -z $_stashing_alias_assign ]]; then
157 eval "$stash_which=\"$stash_value\""
164 if [[ -z $stashed ]]; then
165 # Nothing in the variable we're stashing, but make a note that we stashed so we
166 # do the right thing when unstashing. Without this, we take no action on unstash
168 # Zsh bug sometimes caues
169 # (eval):1: command not found: __varstash_nostash___tmp__home_dolszewski_src_smartcd_RANDOM_VARIABLE=1
170 # fixed in zsh commit 724fd07a67f, version 4.3.14
171 if [[ -z $already_stashed ]]; then
172 eval "export __varstash_nostash__$stash_name=1"
175 # In the case of a previously unset variable that we're assigning too, export it
176 if [[ $stash_which != $stash_expression && -z $_stashing_alias_assign ]]; then
177 eval "export $stash_which=\"$stash_value\""
182 unset -v _stashing_alias_assign
186 function get_autostash_array_name() {
187 local autostash_name=$(_mangle_var AUTOSTASH)
188 # Create a scalar variable linked to an array (for exporting).
189 local autostash_array_name=${(L)autostash_name}
190 if ! (( ${(P)+autostash_array_name} )); then
191 # Conditionally set it, to prevent error with Zsh 4.3:
192 # can't tie already tied scalar: ...
193 typeset -xT $autostash_name $autostash_array_name
195 ret=$autostash_array_name
198 function autostash() {
199 local run_from_autostash=1
201 local already_stashed=
202 while [[ -n $1 ]]; do
203 if [[ $1 == "alias" && $2 == *=* ]]; then
205 local _stashing_alias_assign=1
210 if [[ -z $already_stashed ]]; then
212 get_autostash_array_name
213 eval "$ret=(\$$ret \$varname)"
216 unset -v _stashing_alias_assign
221 while [[ -n $1 ]]; do
222 local unstash_which=$1
223 if [[ -z $unstash_which ]]; then
227 local unstash_name=$(_mangle_var $unstash_which)
229 # This bit is a little tricky. Here are the rules:
230 # 1) unstash any alias, function, or variable which matches
231 # 2) if one or more matches, but not all, delete any that did not
232 # 3) if none match but nostash is found, delete all
233 # 4) if none match and nostash not found, do nothing
236 if [[ -n "$(eval echo \$__varstash_alias__$unstash_name)" ]]; then
237 eval "alias $(eval echo \$__varstash_alias__$unstash_name)"
238 unset __varstash_alias__$unstash_name
240 local unstashed_alias=1
243 # Unstash any function
244 if [[ -n "$(eval echo \$__varstash_function__$unstash_name)" ]]; then
245 eval "function $(eval echo -e \"\$__varstash_function__$unstash_name\")"
246 unset __varstash_function__$unstash_name
248 local unstashed_function=1
251 # Unstash any variable
252 if [[ -n "$(declare -p __varstash_array__$unstash_name 2>/dev/null)" ]]; then
253 eval "$unstash_which=(\"\${__varstash_array__$unstash_name""[@]}\")"
254 unset __varstash_array__$unstash_name
256 local unstashed_variable=1
257 elif [[ -n "$(declare -p __varstash_export__$unstash_name 2>/dev/null)" ]]; then
258 eval "export $unstash_which=\"\$__varstash_export__$unstash_name\""
259 unset __varstash_export__$unstash_name
261 local unstashed_variable=1
262 elif [[ -n "$(declare -p __varstash_variable__$unstash_name 2>/dev/null)" ]]; then
263 # Unset variable first to reset export
264 unset -v $unstash_which
265 eval "$unstash_which=\"\$__varstash_variable__$unstash_name\""
266 unset __varstash_variable__$unstash_name
268 local unstashed_variable=1
271 # Unset any values which did not exist at time of stash
272 local nostash="$(eval echo \$__varstash_nostash__$unstash_name)"
273 unset __varstash_nostash__$unstash_name
274 if [[ ( -n "$nostash" && -z "$unstashed" ) || ( -n "$unstashed" && -z "$unstashed_alias" ) ]]; then
275 unalias $unstash_which 2>/dev/null
277 if [[ ( -n "$nostash" && -z "$unstashed" ) || ( -n "$unstashed" && -z "$unstashed_function" ) ]]; then
278 unset -f $unstash_which 2>/dev/null
280 if [[ ( -n "$nostash" && -z "$unstashed" ) || ( -n "$unstashed" && -z "$unstashed_variable" ) ]]; then
281 # Don't try to unset illegal variable names
282 # Using substitution to avoid using regex, which might fail to load on Zsh (minimal system).
283 if [[ ${unstash_which//[^a-zA-Z0-9_]/} == $unstash_which && $unstash_which != [0-9]* ]]; then
284 unset -v $unstash_which
292 function autounstash() {
293 # If there is anything in (mangled) variable AUTOSTASH, then unstash it
295 get_autostash_array_name
296 if (( ${#${(P)ret}} > 0 )); then
297 local run_from_autounstash=1
298 for autounstash_var in ${(P)ret}; do
299 unstash $autounstash_var
305 function _mangle_var() {
306 local mangle_var_where="${varstash_dir:-$PWD}"
307 mangle_var_where=${mangle_var_where//[^A-Za-z0-9]/_}
308 local mangled_name=${1//[^A-Za-z0-9]/_}
309 echo "_tmp_${mangle_var_where}_${mangled_name}"
312 # vim: filetype=zsh autoindent expandtab shiftwidth=4 softtabstop=4