Question

我正在使用Powershell在一些.txt文件中进行经典查找和替换。如何最后保存文件？我尝试过|设置内容，但没有任何反应。也许我需要先添加内容？

#Find what?
$optionBuilderStringToFind = "optionsBuilder.UseSqlServer"
$findUsingKeywordString = "using Microsoft."

#Replace with
$namespaceAdd = "using Microsoft.Extensions.Configuration;"
$optionBuilderConfigurable ="optionsBuilder.UseSqlServer(_configuration.GetConnectionString(`"Database`") 
 );"

gc -Path .\APSContext.cs | % { 
if ($_ -match "using System;") {
    $_ = $_ + "`n" + $namespaceAdd
    #write-host $_
}
if ($_ -match "optionsBuilder.UseSqlServer") {
    $_ = $optionBuilderConfigurable
    #write-host $_
}
} | Set-Content -Path .\test.cs

更新：这是我要更改的testFile。文件的内容并不重要。我想添加另一个引用，例如“ using Something.Something”，并在文件中间将"optionsBuilder.UseSqlServer("dfjidfjljfiejf88");"替换为"optionsBuilder.UseSqlServer("_configtest");"：

using System;
using Microsoft.EntityFrameworkCore;
using Microsoft.EntityFrameworkCore.Metadata;

namespace SRC.APS.Model.APSDB
{
public partial class APSContext : DbContext
{
    public APSContext()
    {
    }

    public APSContext(DbContextOptions<APSContext> options)
        : base(options)
       protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder)
    {
        if (!optionsBuilder.IsConfigured)
        {

            optionsBuilder.UseSqlServer("dfjidfjljfiejf88");
        }
    }

    protected override void OnModelCreating(ModelBuilder modelBuilder)
    {
        modelBuilder.HasAnnotation("ProductVersion", "2.2.0-rtm-35687");

    }

也许我需要使用输出字符串代替？

Answer 1

Powershell中的任何脚本块都可以产生值。这是通过 not 将值存储在变量中来完成的：

{ $foo = 3 }什么也没产生
{ 3 }产生整数3。

以同样的方式

ForEach-Object { $_ = "something" }什么也没产生
ForEach-Object { $_ = "something"; $_ }产生字符串"something"

您的循环主体不输出任何内容，就像上面的上例一样。因此，Set-Content无关。修改块以实际返回更改后的$_的值：

$replacements = @(
    @{regex='using (System|Potentially|Others);'; replacement='using Microsoft.$1;' }
    @{regex='optionsBuilder\.UseSqlServer\("[^"]*"\)'; replacement='optionsBuilder.UseSqlServer("Database")' }
    # more search/replace pairs
)

Get-Content .\APSContext.cs -Encoding UTF8 | ForEach-Object {
    foreach ($item in $replacements) {
        $_ = $_ -replace $item.regex, $item.replacement
    }
    $_   # <--- this is what produces the line
} | Set-Content -Path .\test.cs -Encoding UTF8

话虽如此，在未指定文本编码的情况下，切勿加载或保存文本文件。对于C＃源代码文件，我认为UTF-8是默认设置。

而且那，用正则表达式修改源代码不是一件好事。如果这是一次性的，那就好。如果您计划定期执行此操作，则说明您做错了什么。使用配置文件或环境变量，而不是保留经常更改的代码库文字值。

Answer 2

正如我所提到的-正如Tomalak所指出-您对当前管道对象的处理是故障的根源。 [ grin ]此代码修复了IF级联中的逻辑错误[使用switch块可能会更好]，消除不明智的$_摆弄，然后确保总是一些输出。

# fake reading in a text file
#    in real life, use Get-Content
$InStuff = @'
using System;
using Microsoft.EntityFrameworkCore;
using Microsoft.EntityFrameworkCore.Metadata;

namespace SRC.APS.Model.APSDB
{
public partial class APSContext : DbContext
{
    public APSContext()
    {
    }

    public APSContext(DbContextOptions<APSContext> options)
        : base(options)
       protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder)
    {
        if (!optionsBuilder.IsConfigured)
        {

            optionsBuilder.UseSqlServer("dfjidfjljfiejf88");
        }
    }

    protected override void OnModelCreating(ModelBuilder modelBuilder)
    {
        modelBuilder.HasAnnotation("ProductVersion", "2.2.0-rtm-35687");

    }
'@ -split [environment]::NewLine

#Find what?
$optionBuilderStringToFind = "optionsBuilder.UseSqlServer"
$findUsingKeywordString = "using Microsoft."

#Replace with
$namespaceAdd = 'using Microsoft.Extensions.Configuration;'
$optionBuilderConfigurable ='optionsBuilder.UseSqlServer(_configuration.GetConnectionString("Database"));'

$InStuff | ForEach-Object { 
    if ($_ -match "using System;")
        {
        $_ + "`n" + $namespaceAdd
        #write-host $_
        }
        elseif ($_ -match "optionsBuilder.UseSqlServer")
        {
        $optionBuilderConfigurable
        #write-host $_
        }
        else
        {
        $_
        }
    }

输出...

using System;
using Microsoft.Extensions.Configuration;
using Microsoft.EntityFrameworkCore;
using Microsoft.EntityFrameworkCore.Metadata;

namespace SRC.APS.Model.APSDB
{
public partial class APSContext : DbContext
{
    public APSContext()
    {
    }

    public APSContext(DbContextOptions<APSContext> options)
        : base(options)
       protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder)
    {
        if (!optionsBuilder.IsConfigured)
        {

optionsBuilder.UseSqlServer(_configuration.GetConnectionString("Database"));
        }
    }

    protected override void OnModelCreating(ModelBuilder modelBuilder)
    {
        modelBuilder.HasAnnotation("ProductVersion", "2.2.0-rtm-35687");

    }

更改.txt文件并使用PowerShell保存

2 个答案: