Add varstash from smartcd

Source: 4fef3d3610/lib/core/varstash
This commit is contained in:
Daniel Hahler 2014-11-15 16:24:26 +01:00
parent c12b861952
commit 54124e128b
1 changed files with 408 additions and 0 deletions

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################################################################################
# Stash/unstash support for per-directory variables
#
# Copyright (c) 2009,2012 Dave Olszewski <cxreg@pobox.com>
# http://github.com/cxreg/smartcd
#
# This code is released under GPL v2 and the Artistic License, and
# may be redistributed under the terms of either.
#
#
# This library allows you to save the current value of a given environment
# variable in a temporary location, so that you can modify it, and then
# later restore its original value.
#
# Note that you will need to be in the same directory you were in when you
# stashed in order to successfully unstash. This is because the temporary
# variable is derived from your current working directory's path.
#
# Usage:
# stash PATH
# export PATH=/something/else
# [...]
# unstash PATH
#
# Note that this was written for use with, and works very well with,
# smartcd. See the documentation there for examples.
#
# An alternate usage is `autostash' which will trigger autounstash when
# leaving the directory, if combined with smartcd. This reduces the amount
# of explicit configuration you need to provide:
#
# autostash PATH
# export PATH=/something/else
#
# You may also do both operations on line line, leaving only the very succinct
#
# autostash PATH=/something/else
#
# If you run stash, unstash, or varstash interactively, they will instruct
# you on how to create smartcd scripts for performing those actions
# automatically. You can affect this behavior with several variables:
#
# VARSTASH_QUIET - Set if you'd rather not see these notices
#
# VARSTASH_AUTOCONFIG - Set if you want the suggested actions to be
# performed automatically
#
# VARSTASH_AUTOEDIT - Set if you want it to set the values, but also
# give you an opportunity to edit the file
#
# If you attempt to stash the same value twice, a warning will be displayed
# and the second stash will not occur. To make it happen anyway, pass -f
# as the first argument to stash.
#
# $ stash FOO
# $ stash FOO
# You have already stashed FOO, please specify "-f" if you want to overwrite another stashed value
# $ stash -f FOO
# $
#
# This rule is a bit different if you are assigning a value and the variable
# has already been stashed. In that case, the new value will be assigned, but
# the stash will not be overwritten. This allows for non-conflicting chained
# stash-assign rules.
#
################################################################################
function stash() {
if [[ $1 == "-f" ]]; then
local force=1; shift
fi
if [[ -n $1 ]] && [[ -z $run_from_smartcd ]] && [[ -z $run_from_autostash ]]; then
local working_dir="${varstash_dir:-$(pwd)}"
local smartcd_dir="$(_smartcd_base)/scripts$working_dir"
local help_action="stashing a variable"
local help_dir=$smartcd_dir
local help_cmd="echo stash $@ >> \"$smartcd_dir/bash_enter\""
local help_which="bash_enter"
_manual_stash_help
fi
while [[ -n $1 ]]; do
if [[ $1 == "alias" && $2 =~ "=" ]]; then
shift
local _stashing_alias_assign=1
continue
fi
local stash_expression=$1
local stash_which=${stash_expression%%'='*}
local stash_name=$(_mangle_var $stash_which)
# Extract the value and make it double-quote safe
local stash_value=${stash_expression#*'='}
stash_value=${stash_value//\\/\\\\}
stash_value=${stash_value//\"/\\\"}
stash_value=${stash_value//\`/\\\`}
stash_value=${stash_value//\$/\\\$}
if [[ ( -n "$(eval echo '$__varstash_alias__'$stash_name)" ||
-n "$(eval echo '$__varstash_function__'$stash_name)" ||
-n "$(eval echo '$__varstash_array__'$stash_name)" ||
-n "$(eval echo '$__varstash_export__'$stash_name)" ||
-n "$(eval echo '$__varstash_variable__'$stash_name)" ||
-n "$(eval echo '$__varstash_nostash__'$stash_name)" )
&& -z $force ]]; then
if [[ -z $already_stashed && ${already_stashed-_} == "_" ]]; then
local already_stashed=1
else
already_stashed=1
fi
if [[ $stash_which == $stash_expression ]]; then
if [[ -z $run_from_smartcd ]]; then
echo "You have already stashed $stash_which, please specify \"-f\" if you want to overwrite another stashed value"
fi
# Skip remaining work if we're not doing an assignment
shift
continue
fi
fi
# Handle any alias that may exist under this name
if [[ -z $already_stashed ]]; then
local alias_def="$(eval alias $stash_which 2>/dev/null)"
if [[ -n $alias_def ]]; then
alias_def=${alias_def#alias }
eval "__varstash_alias__$stash_name=\"$alias_def\""
local stashed=1
fi
fi
if [[ $stash_which != $stash_expression && -n $_stashing_alias_assign ]]; then
eval "alias $stash_which=\"$stash_value\""
fi
# Handle any function that may exist under this name
if [[ -z $already_stashed ]]; then
local function_def="$(declare -f $stash_which)"
if [[ -n $function_def ]]; then
# make function definition quote-safe. because we are going to evaluate the
# source with "echo -e", we need to double-escape the backslashes (so 1 -> 4)
function_def=${function_def//\\/\\\\\\\\}
function_def=${function_def//\"/\\\"}
function_def=${function_def//\`/\\\`}
function_def=${function_def//\$/\\\$}
eval "__varstash_function__$stash_name=\"$function_def\""
local stashed=1
fi
fi
# Handle any variable that may exist under this name
local vartype="$(declare -p $stash_which 2>/dev/null)"
if [[ -n $vartype ]]; then
if [[ -n $ZSH_VERSION ]]; then
local pattern="^typeset"
else
local pattern="^declare"
fi
if [[ $vartype =~ $pattern" -a" ]]; then
# varible is an array
if [[ -z $already_stashed ]]; then
eval "__varstash_array__$stash_name=(\"\${$stash_which""[@]}\")"
fi
elif [[ $vartype =~ $pattern" -x" ]]; then
# variable is exported
if [[ -z $already_stashed ]]; then
eval "__varstash_export__$stash_name=\"\$$stash_which\""
fi
if [[ $stash_which != $stash_expression && -z $_stashing_alias_assign ]]; then
eval "export $stash_which=\"$stash_value\""
fi
else
# regular variable
if [[ -z $already_stashed ]]; then
eval "__varstash_variable__$stash_name=\"\$$stash_which\""
fi
if [[ $stash_which != $stash_expression && -z $_stashing_alias_assign ]]; then
eval "$stash_which=\"$stash_value\""
fi
fi
local stashed=1
fi
if [[ -z $stashed ]]; then
# Nothing in the variable we're stashing, but make a note that we stashed so we
# do the right thing when unstashing. Without this, we take no action on unstash
# Zsh bug sometimes caues
# (eval):1: command not found: __varstash_nostash___tmp__home_dolszewski_src_smartcd_RANDOM_VARIABLE=1
# fixed in zsh commit 724fd07a67f, version 4.3.14
if [[ -z $already_stashed ]]; then
eval "__varstash_nostash__$stash_name=1"
fi
# In the case of a previously unset variable that we're assigning too, export it
if [[ $stash_which != $stash_expression && -z $_stashing_alias_assign ]]; then
eval "export $stash_which=\"$stash_value\""
fi
fi
shift
unset -v _stashing_alias_assign
done
}
function autostash() {
if [[ -n $1 ]] && [[ -z $run_from_smartcd ]]; then
local working_dir="${varstash_dir:-$(pwd)}"
local smartcd_dir="$(_smartcd_base)/scripts$working_dir"
local help_action="autostashing a variable"
local help_dir=$smartcd_dir
local help_cmd="echo autostash $@ >> \"$smartcd_dir/bash_enter\""
local help_which="bash_enter"
_manual_stash_help
fi
local run_from_autostash=1
while [[ -n $1 ]]; do
if [[ $1 == "alias" && $2 =~ "=" ]]; then
shift
local _stashing_alias_assign=1
fi
local already_stashed=
stash "$1"
if [[ -z $already_stashed ]]; then
local autostash_name=$(_mangle_var AUTOSTASH)
local varname=${1%%'='*}
apush $autostash_name "$varname"
fi
shift
unset -v _stashing_alias_assign
done
}
function unstash() {
if [[ -n $1 ]] && [[ -z $run_from_smartcd ]] && [[ -z $run_from_autounstash ]]; then
local working_dir=${varstash_dir:-$(pwd)}
local smartcd_dir="$(_smartcd_base)/scripts$working_dir"
local help_action="unstashing a variable"
local help_dir=$smartcd_dir
local help_cmd="echo unstash $@ >> \"$smartcd_dir/bash_leave\""
local help_which="bash_leave"
_manual_stash_help
fi
while [[ -n $1 ]]; do
local unstash_which=$1
if [[ -z $unstash_which ]]; then
continue
fi
local unstash_name=$(_mangle_var $unstash_which)
# This bit is a little tricky. Here are the rules:
# 1) unstash any alias, function, or variable which matches
# 2) if one or more matches, but not all, delete any that did not
# 3) if none match but nostash is found, delete all
# 4) if none match and nostash not found, do nothing
# Unstash any alias
if [[ -n "$(eval echo \$__varstash_alias__$unstash_name)" ]]; then
eval "alias $(eval echo \$__varstash_alias__$unstash_name)"
unset __varstash_alias__$unstash_name
local unstashed=1
local unstashed_alias=1
fi
# Unstash any function
if [[ -n "$(eval echo \$__varstash_function__$unstash_name)" ]]; then
eval "function $(eval echo -e \"\$__varstash_function__$unstash_name\")"
unset __varstash_function__$unstash_name
local unstashed=1
local unstashed_function=1
fi
# Unstash any variable
if [[ -n "$(declare -p __varstash_array__$unstash_name 2>/dev/null)" ]]; then
eval "$unstash_which=(\"\${__varstash_array__$unstash_name""[@]}\")"
unset __varstash_array__$unstash_name
local unstashed=1
local unstashed_variable=1
elif [[ -n "$(declare -p __varstash_export__$unstash_name 2>/dev/null)" ]]; then
eval "export $unstash_which=\"\$__varstash_export__$unstash_name\""
unset __varstash_export__$unstash_name
local unstashed=1
local unstashed_variable=1
elif [[ -n "$(declare -p __varstash_variable__$unstash_name 2>/dev/null)" ]]; then
# Unset variable first to reset export
unset -v $unstash_which
eval "$unstash_which=\"\$__varstash_variable__$unstash_name\""
unset __varstash_variable__$unstash_name
local unstashed=1
local unstashed_variable=1
fi
# Unset any values which did not exist at time of stash
local nostash="$(eval echo \$__varstash_nostash__$unstash_name)"
unset __varstash_nostash__$unstash_name
if [[ ( -n "$nostash" && -z "$unstashed" ) || ( -n "$unstashed" && -z "$unstashed_alias" ) ]]; then
unalias $unstash_which 2>/dev/null
fi
if [[ ( -n "$nostash" && -z "$unstashed" ) || ( -n "$unstashed" && -z "$unstashed_function" ) ]]; then
unset -f $unstash_which 2>/dev/null
fi
if [[ ( -n "$nostash" && -z "$unstashed" ) || ( -n "$unstashed" && -z "$unstashed_variable" ) ]]; then
# Don't try to unset illegal variable names
if ! [[ $unstash_which =~ [^a-zA-Z0-9_] || $unstash_which =~ ^[0-9] ]]; then
unset -v $unstash_which
fi
fi
shift
done
}
function autounstash() {
# If there is anything in (mangled) variable AUTOSTASH, then unstash it
local autounstash_name=$(_mangle_var AUTOSTASH)
if (( $(alen $autounstash_name) > 0 )); then
local run_from_autounstash=1
while (( $(alen $autounstash_name) > 0 )); do
local autounstash_var=$(afirst $autounstash_name)
ashift $autounstash_name >/dev/null
unstash $autounstash_var
done
unset $autounstash_name
fi
}
function _mangle_var() {
local mangle_var_where="${varstash_dir:-$(pwd)}"
mangle_var_where=${mangle_var_where//[^A-Za-z0-9]/_}
local mangled_name=${1//[^A-Za-z0-9]/_}
echo "_tmp_${mangle_var_where}_${mangled_name}"
}
function _manual_stash_help() {
# instruct user how to create bash_enter or bash_leave
if [[ -n $VARSTASH_AUTOEDIT || -n $VARSTASH_AUTOCONFIG ]]; then
if [[ -z $VARSTASH_QUIET ]]; then
echo "varstash: Automatically running $help_cmd"
fi
if [[ ! -d $help_dir ]]; then
mkdir -p "$help_dir"
fi
eval $help_cmd
if [[ -n $VARSTASH_AUTOEDIT ]]; then
varstash_edit $help_which
fi
elif [[ -z $VARSTASH_QUIET ]]; then
echo "############################################################################"
echo "# You are manually $help_action. To automatically perform this"
echo "# whenever you enter this directory, paste the following command(s):"
if [[ ! -d $help_dir ]]; then
echo "mkdir -p \"$help_dir\""
fi
echo "$help_cmd"
echo "############################################################################"
fi
}
# A couple convenient aliases for smartcd_edit
function autostash_edit() {
varstash_edit "$@"
}
function varstash_edit() {
local file="$1"
local dir="$2"
if [[ -n $ZSH_VERSION ]]; then
if [[ $(type smartcd_edit) == "smartcd_edit is a shell function" ]]; then
local can_run=1
fi
else
if [[ $(type -t smartcd_edit) == "function" ]]; then
local can_run=1
fi
fi
if [[ -n "$can_run" ]]; then
# XXX - no support for "--host" or "--system" with this (yet?)
_smartcd_file_check "$file" "global" "" edit "$dir"
else
echo "smartcd not loaded, cannot run smartcd_edit"
fi
}
# Run deferred smartcd if we're waiting for it, and arrays is also loaded
if [[ -n "$smartcd_initially_deferred" && -n "$(fn_exists apush)" && -z "$SMARTCD_NOINITIAL" ]]; then
smartcd_skip_action=1
smartcd_run_mainline=1
smartcd cd
unset smartcd_skip_action
unset smartcd_initially_deferred
fi
# vim: filetype=sh autoindent expandtab shiftwidth=4 softtabstop=4