为何returnFile函数跳过首行后仍返回完整字符串？

It sounds like your returnFile function isn't correctly skipping the first line when you specify -skip 1. Let's walk through the most common causes and fixes for this problem.

1. The -skip Parameter Isn't Being Used in the Function Body #

The most likely issue is that your function defines the -skip parameter but doesn't actually pass it to the file-reading cmdlet. For example, if your function looks like this:

function returnFile {
    param(
        [string]$path,
        [int]$skip = 0
    )
    # ❌ -skip parameter is defined but not used here
    Get-Content -Path $path
}

To fix this, you need to pass the -skip value to Get-Content using its -Skip parameter:

function returnFile {
    param(
        [Parameter(Mandatory=$true)]
        [string]$path,
        [int]$skip = 0
    )
    # ✅ Use the -Skip parameter to skip the specified number of lines
    Get-Content -Path $path -Skip $skip
}

2. Using -Raw with Get-Content Breaks Line Skipping #

If your function uses Get-Content -Raw, this reads the entire file into a single string. Since -Skip operates on individual lines, this parameter will be ignored because there's only one "line" (the entire file). For example:

function returnFile {
    param(
        [string]$path,
        [int]$skip = 0
    )
    # ❌ -Skip is ineffective when using -Raw
    Get-Content -Path $path -Raw -Skip $skip
}

If you need the output as a single string (without the first line), read the lines first, skip the desired number, then join them back together:

function returnFile {
    param(
        [Parameter(Mandatory=$true)]
        [string]$path,
        [int]$skip = 0
    )
    # Read lines, skip the first N, then join into a single string
    $lines = Get-Content -Path $path -Skip $skip
    $lines -join "`n" # Use "`r`n" for Windows-style line endings
}

3. Verify Parameter Binding and Input Paths #

Double-check that:

• The $CSVs[$i] variable contains a valid, accessible file path (debug with Write-Host $CSVs[$i] to confirm).
• The function's -skip parameter is correctly defined (no typos, and it's of type [int]).
• PowerShell is correctly passing the -skip 1 value to the function (add a debug line inside the function like Write-Host "Skipping $skip lines" to verify).

Bonus: Merging CSV Files Efficiently #

Since your end goal is to merge CSV files with identical headers, here's a streamlined approach that avoids manual line skipping:

# Get the header from the first file
$header = Get-Content -Path $CSVs[0] -TotalCount 1

# Combine all files, skipping headers except the first
$mergedData = $header + ($CSVs | ForEach-Object {
    Get-Content -Path $_ -Skip 1
})

# Save to a new CSV
$mergedData | Out-File -Path "merged.csv" -Encoding UTF8

This approach ensures you only keep one header row and append all data rows from subsequent files.

内容的提问来源于stack exchange，提问作者Tyler Montney