在bash中使用空格傳遞參數

Question

我很感興趣的是在bash腳本中使用動態生成的參數調用某些函數。

但是，如果某些參數有空格，它似乎不起作用。

讓我們有這樣的測試腳本：

#!/bin/bash 
# file uu.sh 
[[ -z $1 ]] || echo '$1' $1 
[[ -z $2 ]] || echo '$2' $2 
[[ -z $3 ]] || echo '$3' $3 
[[ -z $4 ]] || echo '$4' $4 
[[ -z $5 ]] || echo '$5' $5 
[[ -z $6 ]] || echo '$6' $6 
[[ -z $7 ]] || echo '$7' $7 
[[ -z $8 ]] || echo '$8' $8 
[[ -z $9 ]] || echo '$9' $9 
[[ -z $0 ]] || echo '$0' $0 

我的任何腳本：

#!/bin/bash 
# file vv.sh 
ARR=(-x) 
ARR+=($1) 
ARR+=("$1") 
ARR+=("'$1'") 
ARR+=("\"$1\"") 
bash uu.sh ${ARR[*]} 
echo 
bash uu.sh "${ARR[*]}" 

當調用bash vv.sh "a b"我得到以下結果：

$2 -x 
$2 a 
$3 b 
$4 a 
$5 b 
$6 'a 
$7 b' 
$8 "a 
$9 b" 
$0 uu.sh 

$1 -x a b a b 'a b' "a b" 
$0 uu.sh 

我期待的方式將變量傳遞給uu.sh，例如結果如下：

$1 -x 
$2 a b 
$0 uu.sh 

（我可以通過調用bash uu.sh -x a\ b直接獲得，或bash uu.sh -x "a b"，或bash uu.sh -x 'a b'）

Answer 1

你應該有vv.sh這樣才能夠在第二個參數-x後，所有的參數傳遞給uu.sh：

#!/bin/bash 
# file vv.sh 
ARR=(-x) # initialize array with "-x" as first element 
ARR+=("$1") # append 1st argument in second element of array 
bash uu.sh "${ARR[@]}" # call uu.sh with quoted and [@] 

然後把它作爲（見報價參數）：

bash vv.sh "a b" 

...這將發出作爲輸出：

$1 -x 
$2 a b 
$0 uu.sh 

Answer 2

這裏是$*和$@也，你應該總是引用變量（除非你知道爲什麼不想）之間的差異:)

#uu.sh 
[[ -z "$1" ]] || echo '$1' "$1" 
[[ -z "$2" ]] || echo '$2' "$2" 
[[ -z "$3" ]] || echo '$3' "$3" 
[[ -z "$4" ]] || echo '$4' "$4" 
[[ -z "$5" ]] || echo '$5' "$5" 
[[ -z "$6" ]] || echo '$6' "$6" 
[[ -z "$7" ]] || echo '$7' "$7" 
[[ -z "$8" ]] || echo '$8' "$8" 
[[ -z "$9" ]] || echo '$9' "$9" 
[[ -z "$0" ]] || echo '$0' "$0" 

和vv.sh

ARR=(-x) 
ARR+=($1) 
ARR+=("$1") 
ARR+=("'$1'") 
ARR+=("\"$1\"") 

echo 'using quoted ARR[@]' 
printf "=%s=\n" "${ARR[@]}" 

echo 'using unquoted ARR[@]' 
printf "=%s=\n" ${ARR[@]} 

echo 'using quoted ARR[*]' 
printf "=%s=\n" "${ARR[*]}" 

echo 'using unquoted ARR[*]' 
printf "=%s=\n" ${ARR[*]} 

echo "running UU" 
bash uu.sh "${ARR[@]}" 

輸出：

using quoted ARR[@] 
=-x= 
=A= 
=B= 
=A B= 
='A B'= 
="A B"= 
using unquoted ARR[@] 
=-x= 
=A= 
=B= 
=A= 
=B= 
='A= 
=B'= 
="A= 
=B"= 
using quoted ARR[*] 
=-x A B A B 'A B' "A B"= 
using unquoted ARR[*] 
=-x= 
=A= 
=B= 
=A= 
=B= 
='A= 
=B'= 
="A= 
=B"= 
running UU 
$1 -x 
$2 A 
$3 B 
$4 A B 
$5 'A B' 
$6 "A B" 
$0 uu.sh 

Answer 3

"${array[*]}"和"$*"膨脹到單個字與陣列成員或用空格接合位置參數。這幾乎沒有用處。相反，使用"${array[@]}"或"$@"，這會擴展所有陣列成員以分隔單詞。 （見Arrays和Special parameters手冊中。）

所以當你做bash uu.sh "${ARR[*]}"命令傳遞一個字符串作爲參數，並與bash uu.sh ${ARR[*]}沒有報價，因此陣列get split on whitespace的所有內容。