PowerShell将index [0]指向字符串的第一个实例，将index [1]指向第二个实例，依此类推，直到完成 [英] PowerShell index[0] to the first instance of the string, index[1] to the second instance and so on till finished

问题描述

例如，将LINE2 1243替换为LINE2 1，因为它位于test.txt的第1行.

For example, replace LINE2 1243 with LINE2 1 because it is on line 1 of test.txt.

# Find the line number: 
$lines = sls "LINE2" test.txt | Select-Object -ExpandProperty LineNumber

test.txt:

abc LINE2 1243
lmn LINE2 1250
xyz LINE2 1255

使用:

gc test.txt | % { $_ -replace "LINE2.*", "LINE2 $lines" }

我得到:

abc LINE2 1 2 3
lmn LINE2 1 2 3
xyz LINE2 1 2 3

如何为字符串的第一个实例提供index [0]，仅提供index [0]，为第二个实例提供index [1]，依此类推，直到完成.

How do I supply index[0], and only index[0], to the first instance of the string, index[1] to the second instance and so on till finished.

用另一种方式做:

foreach ($line in $lines){
gc test.txt | % { $_ -replace "LINE2.*", "LINE2 $line" }
}

我得到:

abc LINE2 1
lmn LINE2 1
xyz LINE2 1
abc LINE2 2
lmn LINE2 2
xyz LINE2 2
abc LINE2 3
lmn LINE2 3
xyz LINE2 3

如何仅将字符串的第一个实例获取index[0]，依此类推.

How do I get index[0] to only the first instance of the string and so on.

推荐答案

您可以使用带有索引的for循环来实现此目的(如果我理解正确的话；-)

You could use a for loop with an index to achieve this (If I got you right) ;-)

$lines = Select-String "LINE2" -Path C:\sample\test.txt | Select-Object -ExpandProperty LineNumber
Get-Content -Path C:\sample\test.txt -OutVariable Content

for ($index = 0; $index -lt $lines.count; $index++) {
    $Content[$index] -replace "LINE2.*", "LINE2 $($lines[$index])"
}

输出:

abc LINE2 1
lmn LINE2 2
xyz LINE2 3

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