blob: 32891ca560d8d52c9f7a8ddc4ed2e5285baef06f (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
|
#!/bin/sh
# Copyright 2023 Huawei Cloud Computing Technology Co., Ltd.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
set -e
check_var_name() {
local NAME="$1"
if ! expr match "${NAME}" "[A-Z_a-z][0-9A-Z_a-z]*$" >/dev/null; then
echo "expand_exec error: invalid variable name '${NAME}'"
return 1
fi
return 0
}
in_list() {
local NAME="$1"
local VAR_LIST="$2"
check_var_name "${NAME}" && expr match "${NAME}" "\(${VAR_LIST}\)$" >/dev/null
}
EXPANDED_VAR=
expand_var() {
local NAME="$1"
check_var_name "${NAME}" && EXPANDED_VAR="$(eval "printf \"%s\" \"\${$NAME}\"")"
}
PARSED_ARG=
parse_arg() {
local ARG="$1"
local VAR_LIST="$2"
local RESULT=""
local VAR_NAME=""
local PARSE_EXPR=false
local PARSE_VAR_NAME=false
while [ ${#ARG} -gt 0 ]; do
local NEXT=${ARG#?}
c="${ARG%$NEXT}"
ARG=$NEXT
if $PARSE_VAR_NAME; then
# parse <var> from $(<var>)
if [ "$c" = ")" ]; then
# expand var if in cases list
if in_list "${VAR_NAME}" "${VAR_LIST}" && expand_var "${VAR_NAME}"; then
RESULT="${RESULT}${EXPANDED_VAR}"
else
RESULT="${RESULT}\$(${VAR_NAME})"
fi
VAR_NAME=""
PARSE_VAR_NAME=false
else
# accumulate VAR_NAME
VAR_NAME="${VAR_NAME}$c"
if [ ${#ARG} -eq 0 ]; then
# flush unterminated var name
RESULT="${RESULT}\$(${VAR_NAME}"
fi
fi
else
# parse single char
if $PARSE_EXPR; then
if [ "$c" = "(" ]; then
# found "$("
PARSE_VAR_NAME=true
else
RESULT="${RESULT}\$$c"
fi
PARSE_EXPR=false
elif [ "$c" = "$" ]; then
# found "$"
PARSE_EXPR=true
else
# append char
RESULT="${RESULT}$c"
fi
fi
done
PARSED_ARG="'"
while [ ${#RESULT} -gt 0 ]; do
local NEXT=${RESULT#?}
c="${RESULT%$NEXT}"
RESULT=$NEXT
if [ "$c" = "'" ]; then
PARSED_ARG="${PARSED_ARG}'\\''"
else
PARSED_ARG="${PARSED_ARG}$c"
fi
done
PARSED_ARG="${PARSED_ARG}'"
}
# usage: ./expand_exec [VARS...] -- ARGS...
expand_exec() {
local VAR_LIST=""
local VAR_SEP=""
local EXEC_VEC=""
local EXEC_SEP=""
local READ_ARGS=false
while [ "$#" -ge 1 ]; do
local ARG="$1";shift
if $READ_ARGS; then
parse_arg "${ARG}" "${VAR_LIST}"
EXEC_VEC="${EXEC_VEC}${EXEC_SEP}${PARSED_ARG}"
EXEC_SEP=" "
else
if [ "${ARG}" = "--" ]; then
READ_ARGS=true
elif check_var_name "${ARG}"; then
VAR_LIST="${VAR_LIST}${VAR_SEP}${ARG}"
VAR_SEP="\|"
fi
fi
done
exec /bin/sh -c "${EXEC_VEC}"
}
expand_exec "$@"
|
