Question

将数组写入文件：

PS C:\Users\dharmatech\Downloads> 10, 20, 30 | Out-File 'test.txt'

重新读取数组并在其上调用ConvertTo-Json：

PS C:\Users\dharmatech\Downloads> ConvertTo-Json (Get-Content .\test.txt)

结果不是数组的JSON版本...请参阅下面的结果。

如果在从文件读取的数组中的一个字符串上调用Get-Member，您将看到字符串对象已使用少量NoteProperty进行注释。我猜这解释了ConvertTo-Json输出。

使用ConvertTo-JSON在文件中获取阵列的JSON版本的好方法是什么？

[
    {
        "value":  "10",
        "PSPath":  "C:\\Users\\dharmatech\\Downloads\\test.txt",
        "PSParentPath":  "C:\\Users\\dharmatech\\Downloads",
        "PSChildName":  "test.txt",
        "PSDrive":  {
                        "CurrentLocation":  "Users\\dharmatech\\Downloads",
                        "Name":  "C",
                        "Provider":  "Microsoft.PowerShell.Core\\FileSystem",
                        "Root":  "C:\\",
                        "Description":  "",
                        "Credential":  "System.Management.Automation.PSCredential",
                        "DisplayRoot":  null
                    },
        "PSProvider":  {
                           "ImplementingType":  "Microsoft.PowerShell.Commands.FileSystemProvider",
                           "HelpFile":  "System.Management.Automation.dll-Help.xml",
                           "Name":  "FileSystem",
                           "PSSnapIn":  "Microsoft.PowerShell.Core",
                           "ModuleName":  "Microsoft.PowerShell.Core",
                           "Module":  null,
                           "Description":  "",
                           "Capabilities":  52,
                           "Home":  "C:\\Users\\dharmatech",
                           "Drives":  "C D"
                       },
        "ReadCount":  1
    },
    {
        "value":  "20",
        "PSPath":  "C:\\Users\\dharmatech\\Downloads\\test.txt",
        "PSParentPath":  "C:\\Users\\dharmatech\\Downloads",
        "PSChildName":  "test.txt",
        "PSDrive":  {
                        "CurrentLocation":  "Users\\dharmatech\\Downloads",
                        "Name":  "C",
                        "Provider":  "Microsoft.PowerShell.Core\\FileSystem",
                        "Root":  "C:\\",
                        "Description":  "",
                        "Credential":  "System.Management.Automation.PSCredential",
                        "DisplayRoot":  null
                    },
        "PSProvider":  {
                           "ImplementingType":  "Microsoft.PowerShell.Commands.FileSystemProvider",
                           "HelpFile":  "System.Management.Automation.dll-Help.xml",
                           "Name":  "FileSystem",
                           "PSSnapIn":  "Microsoft.PowerShell.Core",
                           "ModuleName":  "Microsoft.PowerShell.Core",
                           "Module":  null,
                           "Description":  "",
                           "Capabilities":  52,
                           "Home":  "C:\\Users\\dharmatech",
                           "Drives":  "C D"
                       },
        "ReadCount":  2
    },
    {
        "value":  "30",
        "PSPath":  "C:\\Users\\dharmatech\\Downloads\\test.txt",
        "PSParentPath":  "C:\\Users\\dharmatech\\Downloads",
        "PSChildName":  "test.txt",
        "PSDrive":  {
                        "CurrentLocation":  "Users\\dharmatech\\Downloads",
                        "Name":  "C",
                        "Provider":  "Microsoft.PowerShell.Core\\FileSystem",
                        "Root":  "C:\\",
                        "Description":  "",
                        "Credential":  "System.Management.Automation.PSCredential",
                        "DisplayRoot":  null
                    },
        "PSProvider":  {
                           "ImplementingType":  "Microsoft.PowerShell.Commands.FileSystemProvider",
                           "HelpFile":  "System.Management.Automation.dll-Help.xml",
                           "Name":  "FileSystem",
                           "PSSnapIn":  "Microsoft.PowerShell.Core",
                           "ModuleName":  "Microsoft.PowerShell.Core",
                           "Module":  null,
                           "Description":  "",
                           "Capabilities":  52,
                           "Home":  "C:\\Users\\dharmatech",
                           "Drives":  "C D"
                       },
        "ReadCount":  3
    }
]
PS C:\Users\dharmatech\Downloads>

Answer 1

这似乎有效：

10, 20, 30 | Out-File 'testfile1.txt'

convertto-json ([string[]](gc testfile1.txt))

[
    "10",
    "20",
    "30"
]

或者，如果你想要它们作为[int]

10, 20, 30 | Out-File 'testfile1.txt'

convertto-json ([int[]](gc testfile1.txt))

[
    10,
    20,
    30
]

Answer 2

Get-Content有一个坏习惯，即通过大量额外信息扩展它输出的字符串。处理大文件时，这可能会导致内存膨胀。我希望Get-Content有一个开关，可以在需要时启用这些额外的属性，这种情况很少见。但是，由于这可能会破坏现有程序，因此请求一个剥去额外属性的参数更为可行。也许像ValueOnly这样的东西？

要解决这些问题，您可以将其作为上面的mjolinor演示，但为了获得最佳性能，请下载到.NET：

ConvertTo-Json ([IO.File]::ReadAllLines("$pwd\test.txt"))

[
    "10",
    "20",
    "30"
]

虽然对于除了非常大的文件之外的任何内容都不需要这样做，但这是一个很好的技巧。

从文件读取的数组上的ConvertTo-Json会产生意外结果

2 个答案: