問題在for循環分配給變量|慶典

Question

我得到命令沒有找到錯誤的代碼如下：

#!/bin/sh 
#set -x 
for i in `cat output`; 
do 
eval "MASTER_$i = $(/usr/efm-2.0/bin/efm cluster-status $i 2>/dev/null |grep "Master" |head -1 |awk -F " " {'print$2'})"; 
echo -e "$MASTER_$i"; 
done 

調試輸出是：

 
./test.sh 
++ cat output 
+for i in '`cat output`' 
++ /usr/efm-2.0/bin/efm cluster-status abc 
++ grep Master 
++ head -1 
++ awk -F ' ' '{print$2}' 
+eval 'MASTER_abc = 10.x.x.x' 
++ MASTER_abc = 10.x.x.x 
**./test.sh: line 5: MASTER_abc: command not found** 
+echo -e abc 
abc 

Answer 1

你有=周圍的空間。 ..如果您嘗試運行eval "i = 1"，它將嘗試運行命令i，參數=和1而不是將i設置爲1。

Answer 2

強烈建議您使用一個bash關聯數組，而不是動態的變量名：

#!/bin/bash 
#set -x 
declare -A master 
while IFS= read -r line; do 
    master["$line"]=$(/usr/efm-2.0/bin/efm cluster-status "$line" 2>/dev/null |awk '/Master/ {print $2; exit}') 
done < output.file 

for line in "${!master[@]}"; do 
    printf "%s\t%s\n" "$line" "${master[$line]}" 
done