Powershell 如何选择字符串并仅输出最后一行文本

无论如何，我可以让我的输出只搜索我搜索的每个字符串的最后一行

$String1 = "Oatmeal"
$String2 = "Cake"
$String1Location = "C:\1.txt"

try {
    Select-String -Path $String1Location -Pattern $String1, $String2 -ErrorAction Stop 
}

catch {
    return ""
}

我的输出是这样的：

C:\1.txt:4:Oatmeal
C:\1.txt:6:Cake
C:\1.txt:9:Cake
C:\1.txt:10:Oatmeal

但我只想看看

C:\1.txt:9:Cake
C:\1.txt:10:Oatmeal

---

提前感谢。

如果您在try块中执行以下操作如何

$found1=Select-String -Path $String1Location -Pattern $String1 -ErrorAction Stop 
$found1[-1]
$found2=Select-String -Path $String1Location -Pattern $String2 -ErrorAction Stop 
$found2[-1]

---

如果您在try块中执行以下操作如何

$found1=Select-String -Path $String1Location -Pattern $String1 -ErrorAction Stop 
$found1[-1]
$found2=Select-String -Path $String1Location -Pattern $String2 -ErrorAction Stop 
$found2[-1]

---

这就是我的结局，它正在发挥作用：

try {
    Select-String -Path $String1Location -Pattern $String1 -ErrorAction Stop | Where-Object {$_ -match $String1} | Select-Object -Last 1
    Select-String -Path $String1Location -Pattern $String2 -ErrorAction Stop | Where-Object {$_ -match $String2} | Select-Object -Last 1
}

---

这就是我的结局，它正在发挥作用：

try {
    Select-String -Path $String1Location -Pattern $String1 -ErrorAction Stop | Where-Object {$_ -match $String1} | Select-Object -Last 1
    Select-String -Path $String1Location -Pattern $String2 -ErrorAction Stop | Where-Object {$_ -match $String2} | Select-Object -Last 1
}

我建议：

$String1 = "Oatmeal"
$String2 = "Cake"
$String1Location = "C:\1.txt"

Select-String -Path $String1Location -Pattern $string1, $string2 -SimpleMatch | Group-Object Line | ForEach-Object {
    $_.Group | Sort-Object LineNumber | Select-Object -Last 1
}

或者使用正则表达式匹配

$StringsToSearch = "Oatmeal","Cake"
$String1Location = "C:\1.txt"

# build the regex
$pattern = '\b(' + (($StringsToSearch | ForEach-Object { [regex]::Escape($_) }) -join '|') + ')\b' 
# this ends up in '\b(Oatmeal|Cake)\b' which means we are looking for these strings as whole string.
# if you also would like to search for strings that contain the search criteria, like 'Pancake',
# then use 
# $pattern = ($StringsToSearch | ForEach-Object { [regex]::Escape($_) }) -join '|'

Select-String -Path $String1Location -Pattern $pattern | Group-Object Line | ForEach-Object {
    $_.Group | Sort-Object LineNumber | Select-Object -Last 1
}

注意：如果希望输出按行号升序排序，只需在最后一个右括号后添加

| Sort Object LineNumber

。

我建议：

$String1 = "Oatmeal"
$String2 = "Cake"
$String1Location = "C:\1.txt"

Select-String -Path $String1Location -Pattern $string1, $string2 -SimpleMatch | Group-Object Line | ForEach-Object {
    $_.Group | Sort-Object LineNumber | Select-Object -Last 1
}

或者使用正则表达式匹配

$StringsToSearch = "Oatmeal","Cake"
$String1Location = "C:\1.txt"

# build the regex
$pattern = '\b(' + (($StringsToSearch | ForEach-Object { [regex]::Escape($_) }) -join '|') + ')\b' 
# this ends up in '\b(Oatmeal|Cake)\b' which means we are looking for these strings as whole string.
# if you also would like to search for strings that contain the search criteria, like 'Pancake',
# then use 
# $pattern = ($StringsToSearch | ForEach-Object { [regex]::Escape($_) }) -join '|'

Select-String -Path $String1Location -Pattern $pattern | Group-Object Line | ForEach-Object {
    $_.Group | Sort-Object LineNumber | Select-Object -Last 1
}

---

注意：如果希望输出按行号升序排序，只需在最后一个右括号后添加

| Sort Object LineNumber

。

最简单的解决方案是IMO追加

| Sort Object Pattern-Unique

如有必要，对对象行号进行排序，使其具有原始顺序

$String1 = "Oatmeal"
$String2 = "Cake"
$String1Location = "C:\1.txt"

try {
    Select-String -Path $String1Location -Pattern $String1, $String2 -ErrorAction Stop |
       Sort-Object Pattern -Unique | Sort-Object LineNumber
}

catch {
    return ""
}

---

最简单的解决方案是IMO附加

|排序对象模式-唯一

如有必要，对对象行号进行排序，使其具有原始顺序

$String1 = "Oatmeal"
$String2 = "Cake"
$String1Location = "C:\1.txt"

try {
    Select-String -Path $String1Location -Pattern $String1, $String2 -ErrorAction Stop |
       Sort-Object Pattern -Unique | Sort-Object LineNumber
}

catch {
    return ""
}

---

这是输出：C:\1.txt:4:燕麦C:\1.txt:6:Cake C:\1.txt:9:Cake C:\1.txt:10:Oatmeat C:\1.txt:10:Oatmeat C:\1.txt:9:Caken我不确定我理解你的意思。您是否在try块中尝试了上述代码？这是输出：C:\1.txt:4:Oatmeat C:\1.txt:6:Cake C:\1.txt:9:Cake C:\1.txt:10:Oatmeat C:\1.txt:10:Oatmeat C:\1.txt:9:Caken我不确定是否理解您的意思。您是否在try块中尝试了上述代码？这里的行就是模式，如果模式只是行的一部分，您的方法将不起作用。因此，最好按模式分组。这里的线条就是模式，如果模式只是线条的一部分，那么你的方法就行不通了。所以最好按模式分组。