Powershell 如何从文件中删除重复文本？

我有一个包含SQL Server数据库列表的文件。我想从文件中删除4个系统数据库[master、model、msdb、tempdb]。我该怎么做

Server1
[DB1]
[DB2]
[DB3]
[master]
[model]
[msdb]
[tempdb]
Server2
[DB1]
[DB2]
[DB3]
[master]
[model]
[msdb]
[tempdb]
Server3
[DB1]
[DB2]
[DB3]
[master]
[model]
[msdb]
[tempdb]

---

如果只想删除行，请执行以下操作：

grep -v -E '^\[(master|model|msdb|tempdb)\]'

如果要删除整个块，请执行以下操作：

perl -0133 -ne 'if ($_ !~ /^(master|model|msdb|tempdb)/) { print "["; print substr($_, 0, -1) }'

---

如果只想删除行，请执行以下操作：

grep -v -E '^\[(master|model|msdb|tempdb)\]'

如果要删除整个块，请执行以下操作：

perl -0133 -ne 'if ($_ !~ /^(master|model|msdb|tempdb)/) { print "["; print substr($_, 0, -1) }'

---

枚举该文件并检查该项是否不符合regexp。这与Yiuh的grep-v示例非常相似

# dbs is here an array, but anything enumerable works.
$dbs = @("[DB1]", "[DB2]", "[DB3]", "[master]", "[model]", "[msdb]", "[tempdb]", "Server2", "[DB1]", "[DB2]", "[DB3]", "[master]", "[model]", "[msdb]", "[tempdb]", "Server3", "[DB1]", "[DB2]", "[DB3]", "[master]", "[model]", "[msdb]", "[tempdb]")

$dbs | ? {!($_ -match "\[(master)|(model)|(msdb)|(tempdb)\]")}

---

枚举该文件并检查该项是否不符合regexp。这与Yiuh的grep-v示例非常相似

# dbs is here an array, but anything enumerable works.
$dbs = @("[DB1]", "[DB2]", "[DB3]", "[master]", "[model]", "[msdb]", "[tempdb]", "Server2", "[DB1]", "[DB2]", "[DB3]", "[master]", "[model]", "[msdb]", "[tempdb]", "Server3", "[DB1]", "[DB2]", "[DB3]", "[master]", "[model]", "[msdb]", "[tempdb]")

$dbs | ? {!($_ -match "\[(master)|(model)|(msdb)|(tempdb)\]")}

---

一个选项是使用-notcontains

 $system = "[master]","[model]","[msdb]","[tempdb]"
 $new_file = @(get-content db_list.txt |
   where {$system -notcontains $_})
 $new_file | out-file db_list.txt -force

---

一个选项是使用-notcontains

 $system = "[master]","[model]","[msdb]","[tempdb]"
 $new_file = @(get-content db_list.txt |
   where {$system -notcontains $_})
 $new_file | out-file db_list.txt -force