bash shell 将字符串添加到数组
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shell adding string to an array
提问by Pectus Excavatum
I am having some trouble adding a string to an array within a loop. For some reason it always adds the same line. Here is my code:
我在将字符串添加到循环中的数组时遇到了一些麻烦。出于某种原因，它总是添加相同的行。这是我的代码：
declare -a properties
counter=0
while read line
do
if [[ ${line} == *=* ]]
then
properties[${counter}]=${line}
(( counter=counter + 1 ))
fi
done < ${FILE}
for x in ${!properties[@]}
do
echo "the value is $properties[x]"
done
For some reason each element in the array is the first line in the file. I must be doing something wrong, just not sure what.
出于某种原因，数组中的每个元素都是文件中的第一行。我一定是做错了什么，只是不确定是什么。
Any help would be greatly appreciated
任何帮助将不胜感激
回答by anubhava
Try this script:
试试这个脚本：
declare -a properties
while read line
do
[[ "${line}" == *=* ]] && properties+=("$line")
done < "${FILE}"
for x in "${properties[@]}"
do
echo "the value is "$x"
done
回答by Henk Langeveld
As @twalberg mentions in this comment, the problem is not in the top loop, but in the bottom one:
正如@twalberg在此评论中提到的，问题不在顶部循环中，而在底部循环中：
for x in ${!properties[@]}
do
echo "the value is $properties[x]"
done
Array references alwaysneed braces { ... }to expand properly.
数组引用总是需要大括号{ ... }才能正确扩展。
For some reason each element in the array is the first line in the file.
出于某种原因，数组中的每个元素都是文件中的第一行。
Not so. The array is correctly populated, but you need to change the reference to the array from:
不是这样。数组已正确填充，但您需要更改对数组的引用：
echo "the value is $properties[x]"
to:
到：
echo "the value is ${properties[x]}"
Just a simple oversight.
只是一个简单的疏忽。
回答by DopeGhoti
A much simpler way to add an element to an array is to simply use the syntax:
将元素添加到数组的一种更简单的方法是简单地使用语法：
VARNAME+=("content")
Also, as written, your bug may be here:
此外，正如所写，您的错误可能在这里：
(( counter=counter + 1 ))
It probably should be one of these three:
它可能应该是这三个之一：
(( counter=$counter + 1 ))
counter+=1
counter=$[$counter+1]
counter=$(($counter + 1))
回答by javaPlease42
This KornShell (ksh) script worked fine for me. Let me know if anything.
这个 KornShell (ksh) 脚本对我来说很好用。让我知道如果有的话。
readFileArrayExample.ksh
读取文件数组示例.ksh
#! /usr/bin/ksh
file=input.txt
typeset -i counter=0
while read line
do
if [[ ${line} == *=* ]]; then
properties[${counter}]="${line}"
((counter = counter + 1))
echo "counter:${counter}"
fi
done < "${file}"
#echo ${properties[*]}
for x in "${properties[@]}"
do
echo "${x}"
done
readFileArrayExample.ksh Output:
readFileArrayExample.ksh 输出：
@:/tmp #ksh readFileArrayExample.ksh
counter:1
counter:2
counter:3
a=b
a=1
b=1
@:/tmp #
input.txt
输入.txt
a-b
a+b
a=b
a=1
b=1
1-a
