问题在for循环分配给变量|庆典

Question

我得到命令没有找到错误的代码如下：

#!/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 

调试输出是：

 
./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=周围的空间。 ..如果您尝试运行eval "i = 1"，它将尝试运行命令i，参数=和1而不是将i设置为1。

Answer 2

强烈建议您使用一个bash关联数组，而不是动态的变量名：

#!/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