如何修改PowerShell字符串查找脚本让输出按换行显示？

我编写了一个PowerShell脚本script.ps1，用于在文件内容中查找特定字符串：

$lookup = Read-Host -Prompt "Enter the word you're looking for:"
$res = sls "$lookup" (dir -Recurse *.txt, *.docx, *xlsx)
Write-output "$res"

Read-Host -Prompt "Press Enter to exit"

测试时输入字符串"A"，当前输出所有匹配项挤在一行：

Enter the word youre looking for: A
C:\Users\koyamashinji\Downloads\test\test1.txt:1:ABCDEFGHIJKLMN C:\Users\koyamashinji\Downloads\test\test2.txt:1:ABCDEFGHIJKLMN C:\Users\koyamashinji\Downloads\test\test3.txt:1:ABCDEFGHIJKLMN C:\Users\koyamashinji\Downloads\test\test4.txt:1:ABCDEFGHIJKLMN
Press Enter to exit:

我希望每个匹配项单独换行显示，效果如下：

Enter the word youre looking for: A
C:\Users\koyamashinji\Downloads\test\test1.txt:1:ABCDEFGHIJKLMN
C:\Users\koyamashinji\Downloads\test\test2.txt:1:ABCDEFGHIJKLMN
C:\Users\koyamashinji\Downloads\test\test3.txt:1:ABCDEFGHIJKLMN
C:\Users\koyamashinji\Downloads\test\test4.txt:1:ABCDEFGHIJKLMN
Press Enter to exit:

修改方案 #

问题出在Write-output "$res"这一行——用双引号包裹数组$res时，PowerShell会强制将数组转换为单个字符串，元素默认用空格分隔。只需去掉双引号，直接输出数组即可：

$lookup = Read-Host -Prompt "Enter the word you're looking for:"
$res = sls "$lookup" (dir -Recurse *.txt, *.docx, *xlsx)
Write-Output $res  # 移除双引号

Read-Host -Prompt "Press Enter to exit"

还可以更简洁，省略Write-Output，PowerShell默认会输出未捕获的变量：

$lookup = Read-Host -Prompt "Enter the word you're looking for:"
sls "$lookup" (dir -Recurse *.txt, *.docx, *xlsx)

Read-Host -Prompt "Press Enter to exit"

原理说明 #

sls（即Select-String）返回的是MatchInfo对象数组，直接输出数组时，PowerShell会自动为每个元素单独换行；用双引号包裹数组时，会调用数组的ToString()方法，将所有元素用空格拼接成单一字符串，导致结果挤在一行。

内容的提问来源于stack exchange，提问作者koyamashinji