在shell脚本中的for循环中逐行遍历文本文件。

Question

我有一个名为locations.txt的txt文件

location-1a
location-2c
location-3d
location-4
location-5a
...

我希望迭代我的for循环中的locations.txt文件，每个位置应该用于5个节点，然后应该使用下一个位置。例如，我希望运行以下命令，

server create --location location-1a node-1
server create --location location-1a node-2
server create --location location-1a node-3
server create --location location-1a node-4
server create --location location-1a node-5
server create --location location-2c node-6

.....

到目前为止，我只有一个名为script.sh的脚本，它从cli获取一个参数。我不能像我想的那样改变地点。

mapfile -t locationArr < ~/Documents/files/locations.txt
serverCounter=1
locationCounter=1
counter=1

counter=1
for (( i = 1; i <= $1; i++ ))
do
 server create --location $locationArr[$locationCounter] node-$i
 counter=$((counter+1))
 if [ $counter == 5 ]
 then
  counter=1
  locationCounter=$((locationCounter+1))
done

我想要像这样的

if counter == 5:
 counter=0
 nextline 

例如，如果我运行script.sh 11，我希望得到以下结果，

server create --location location-1a node-1
server create --location location-1a node-2
server create --location location-1a node-3
server create --location location-1a node-4
server create --location location-1a node-5
server create --location location-2c node-6
server create --location location-2c node-7
server create --location location-2c node-8
server create --location location-2c node-9
server create --location location-2c node-10
server create --location location-3d node-11

如何在for循环中迭代location.txt文件？我是否应该将文本文件转换为某种列表变量？

Answer 1

这是我的尝试：

counter=1
while IFS= read -r line
do
    for (( i=1; i <= 5 && $counter <= $1; i++ ))
    do
     server create --location $line node-$counter
     counter=$((counter+1))
    done 
done < ~/Documents/files/locations.txt

产出为11：

server create --location location-1a node-1
server create --location location-1a node-2
server create --location location-1a node-3
server create --location location-1a node-4
server create --location location-1a node-5
server create --location location-2c node-6
server create --location location-2c node-7
server create --location location-2c node-8
server create --location location-2c node-9
server create --location location-2c node-10
server create --location location-3d node-11

Answer 2

总纲：

用于从locations.txt

• inner循环读取位置的
• 外部循环，用于在每次生成节点时为给定位置生成5个节点的最大值，如果计数器>输入' max‘，则增加计数
• ，然后突破循环

。

上述措施的一项实施：

max=${1}
curr=1

while read -r location
do
    for i in {1..5}
    do
        echo "server create --location ${location} node-${curr}"
        curr=$((curr+1))
        [ ${curr} -gt ${max} ] && break 2
    done
done < locations.txt

用max=${1}=11进行测试运行

server create --location location-1a node-1
server create --location location-1a node-2
server create --location location-1a node-3
server create --location location-1a node-4
server create --location location-1a node-5
server create --location location-2c node-6
server create --location location-2c node-7
server create --location location-2c node-8
server create --location location-2c node-9
server create --location location-2c node-10
server create --location location-3d node-11

OP可以为大于0的整数添加额外的max检查。

Answer 3

使用单循环完成，没有Bashism POSIX语法：

#!/usr/bin/env sh

i=0
while [ $i -lt "$1" ] && {
  [ $((i % 5)) -ne 0 ] || IFS= read -r line || [ "$line" ]
}; do
  server create --location "$line" "node-$((i = i + 1))"
done <locations.txt