GenXdev.FileSystem

1.266.2025

Functions/GenXdev.FileSystem/Expand-Path.ps1

<##############################################################################
Part of PowerShell module : GenXdev.FileSystem
Original cmdlet filename : Expand-Path.ps1
Original author : René Vaessen / GenXdev
Version : 1.266.2025
################################################################################
MIT License
 
Copyright 2021-2025 GenXdev
 
Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:
 
The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.
 
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.
################################################################################>
###############################################################################
<#
.SYNOPSIS
Expands any given file reference to a full pathname.
 
.DESCRIPTION
Expands any given file reference to a full pathname, with respect to the user's
current directory. Can optionally assure that directories or files exist.
 
.PARAMETER FilePath
The file path to expand to a full path.
 
.PARAMETER CreateDirectory
Will create directory if it does not exist.
 
.PARAMETER CreateFile
Will create an empty file if it does not exist.
 
.EXAMPLE
Expand-Path -FilePath ".\myfile.txt" -CreateFile
 
.EXAMPLE
ep ~\documents\test.txt -CreateFile
#>
function Expand-Path {

    [CmdletBinding()]
    [Alias('ep')]

    param(
        ########################################################################
        [Parameter(
            Mandatory = $true,
            Position = 0,
            ValueFromPipeline = $true,
            ValueFromPipelineByPropertyName = $true,
            HelpMessage = 'Path to expand'
        )]
        [ValidateNotNullOrEmpty()]
        [string] $FilePath,
        ########################################################################
        [Parameter(
            Mandatory = $false,
            HelpMessage = 'Will create directory if it does not exist'
        )]
        [switch] $CreateDirectory,
        ########################################################################
        [Parameter(
            Mandatory = $false,
            HelpMessage = 'Will create an empty file if it does not exist'
        )]
        [switch] $CreateFile,
        ########################################################################
        [Parameter(
            Mandatory = $false,
            HelpMessage = 'Will delete the file if it already exists'
        )]
        [switch] $DeleteExistingFile,
        ########################################################################
        [Parameter(
            Mandatory = $false,
            HelpMessage = 'Will force the use of a specific drive'
        )]
        [char] $ForceDrive = '*',
        ########################################################################
        [Parameter(
            Mandatory = $false,
            HelpMessage = 'Will throw if file does not exist'
        )]
        [switch] $FileMustExist,
        ########################################################################
        [Parameter(
            Mandatory = $false,
            HelpMessage = 'Will throw if directory does not exist'
        )]
        [switch] $DirectoryMustExist
        ########################################################################
    )

    begin {

        # normalize path separators and remove double separators
        [string] $normalizedPath = $FilePath.Trim().Replace('\', [IO.Path]::DirectorySeparatorChar).
        Replace('/', [IO.Path]::DirectorySeparatorChar);

        if ($normalizedPath.StartsWith([IO.Path]::DirectorySeparatorChar + [IO.Path]::DirectorySeparatorChar)) {

            $normalizedPath = [IO.Path]::DirectorySeparatorChar + [IO.Path]::DirectorySeparatorChar +
            $normalizedPath.Substring(2).Replace(
                [IO.Path]::DirectorySeparatorChar + [IO.Path]::DirectorySeparatorChar,
                [IO.Path]::DirectorySeparatorChar
            )

            if (($ForceDrive -ne '*') -and
                ('ABCDEFGHIJKLMNOPQRSTUVWXYZ'.IndexOf(($ForceDrive -as [string]).ToUpperInvariant()) -ge 0)) {

                $i = $normalizedPath.IndexOf([IO.Path]::DirectorySeparatorChar, 2);
                $normalizedPath = $ForceDrive + ':' + (

                    $i -lt 0 ? ([IO.Path]::DirectorySeparatorChar) : $normalizedPath.Substring($i)
                )
            }
        }
        else {

            $normalizedPath = $normalizedPath.Replace(
                [IO.Path]::DirectorySeparatorChar + [IO.Path]::DirectorySeparatorChar,
                [IO.Path]::DirectorySeparatorChar
            )
        }

        # check if path ends with a directory separator
        $hasTrailingSeparator = $normalizedPath.EndsWith(
            [System.IO.Path]::DirectorySeparatorChar) -or
        $normalizedPath.EndsWith([System.IO.Path]::AltDirectorySeparatorChar)
    }


    process {

        # expand home directory if path starts with ~
        if ($normalizedPath.StartsWith('~')) {

            if (($ForceDrive -ne '*') -and
                ('ABCDEFGHIJKLMNOPQRSTUVWXYZ'.IndexOf(($ForceDrive -as [string]).ToUpperInvariant()) -ge 0)) {

                $i = $normalizedPath.IndexOf([IO.Path]::DirectorySeparatorChar, 1);
                $normalizedPath = $ForceDrive + ':' + (

                    $i -lt 0 ? [IO.Path]::DirectorySeparatorChar + '**' + [IO.Path]::DirectorySeparatorChar : ('\**' + $normalizedPath.Substring($i))
                )
            }
            else {

                $normalizedPath = Microsoft.PowerShell.Management\Join-Path (Microsoft.PowerShell.Management\Convert-Path ~) `
                    $normalizedPath.Substring(1)
            }
        }

        if ((($normalizedPath.Length -gt 1) -and
                ($normalizedPath.Substring(1, 1) -eq ':'))) {

            if (($ForceDrive -ne '*') -and
                ('ABCDEFGHIJKLMNOPQRSTUVWXYZ'.IndexOf(($ForceDrive -as [string]).ToUpperInvariant()) -ge 0)) {
                $i = $normalizedPath.IndexOf([IO.Path]::DirectorySeparatorChar);
                $normalizedPath = $ForceDrive + ':' + [IO.Path]::DirectorySeparatorChar + (($i -eq -1 -and $normalizedPath.Length -gt 2) -or $i -eq 2 ? '**' + [IO.Path]::DirectorySeparatorChar : '') + $normalizedPath.Substring(2)
            }
            else {

                if (($normalizedPath.Length -lt 3) -or ($normalizedPath.Substring(2, 1) -ne [System.IO.Path]::DirectorySeparatorChar)) {

                    Microsoft.PowerShell.Management\Push-Location -LiteralPath $normalizedPath.Substring(0, 2)
                    try {
                        $normalizedPath = "$(Microsoft.PowerShell.Management\Get-Location)$([IO.Path]::DirectorySeparatorChar)$($normalizedPath.Substring(2))"
                        $normalizedPath = [System.IO.Path]::GetFullPath($normalizedPath)
                    }
                    finally {
                        Microsoft.PowerShell.Management\Pop-Location
                    }
                }
            }
        }

        # handle absolute paths (drive letter or UNC)
        if ($normalizedPath.StartsWith([IO.Path]::DirectorySeparatorChar + [IO.Path]::DirectorySeparatorChar)) {

            try {
                $normalizedPath = [System.IO.Path]::GetFullPath($normalizedPath)
            }
            catch {
                Microsoft.PowerShell.Utility\Write-Verbose 'Failed to normalize path, keeping original'
            }
        }
        else {

            if (($ForceDrive -ne '*') -and
                ('ABCDEFGHIJKLMNOPQRSTUVWXYZ'.IndexOf(($ForceDrive -as [string]).ToUpperInvariant()) -ge 0)) {

                if ($normalizedPath.Length -lt 2 -or $normalizedPath.Substring(1, 1) -ne ':') {

                    $newPath = $ForceDrive + ':' + [IO.Path]::DirectorySeparatorChar;

                    while ($normalizedPath.StartsWith('.')) {

                        $i = $normalizedPath.IndexOf([IO.Path]::DirectorySeparatorChar);
                        if ($i -lt 0) {

                            $normalizedPath = ''
                        }
                        else {

                            $normalizedPath = $normalizedPath.Substring($i + 1)
                        }
                    }

                    if ($normalizedPath.StartsWith([IO.Path]::DirectorySeparatorChar)) {

                        $newPath += $normalizedPath
                    }
                    else {

                        $newPath += '**' + [IO.Path]::DirectorySeparatorChar + $normalizedPath
                    }

                    $normalizedPath = $newPath
                }
            }

            # handle relative paths
            try {
                $normalizedPath = [System.IO.Path]::GetFullPath(
                    [System.IO.Path]::Combine($pwd, $normalizedPath))
            }
            catch {
                $normalizedPath = Microsoft.PowerShell.Management\Convert-Path -LiteralPath $normalizedPath
            }
        }

        # handle directory/file creation if requested
        if ($DirectoryMustExist -or $FileMustExist) {

            # get directory path accounting for trailing separator
            $directoryPath = if ($hasTrailingSeparator) {
                [IO.Path]::TrimEndingDirectorySeparator($normalizedPath)
            }
            else {
                [IO.Path]::TrimEndingDirectorySeparator(
                    [System.IO.Path]::GetDirectoryName($normalizedPath))
            }

            # create directory if it doesn't exist
            if ($DirectoryMustExist -and (-not [IO.Directory]::Exists($directoryPath))) {

                throw "Directory does not exist: $directoryPath"
            }

            if ($FileMustExist -and (-not [IO.File]::Exists($normalizedPath))) {

                throw "File does not exist: $normalizedPath"
            }
        }

        # handle directory/file creation if requested
        if ($CreateDirectory -or $CreateFile) {

            # get directory path accounting for trailing separator
            $directoryPath = if ($hasTrailingSeparator) {
                [IO.Path]::TrimEndingDirectorySeparator($normalizedPath)
            }
            else {
                [IO.Path]::TrimEndingDirectorySeparator(
                    [System.IO.Path]::GetDirectoryName($normalizedPath))
            }

            # create directory if it doesn't exist
            if (-not [IO.Directory]::Exists($directoryPath)) {
                $null = [IO.Directory]::CreateDirectory($directoryPath)
                Microsoft.PowerShell.Utility\Write-Verbose "Created directory: $directoryPath"
            }
        }

        # delete existing file if requested
        if ($DeleteExistingFile -and [IO.File]::Exists($normalizedPath)) {

            # verify path doesn't point to existing directory
            if ([IO.Directory]::Exists($normalizedPath)) {
                throw 'Cannot create file: Path refers to an existing directory'
            }

            if (-not (GenXdev.FileSystem\Remove-ItemWithFallback -Path $normalizedPath)) {

                throw "Failed to delete existing file: $normalizedPath"
            }

            Microsoft.PowerShell.Utility\Write-Verbose "Deleted existing file: $normalizedPath"
        }


        # clean up trailing separators except for root paths
        while ([IO.Path]::EndsInDirectorySeparator($normalizedPath) -and
            $normalizedPath.Length -gt 4) {
            $normalizedPath = [IO.Path]::TrimEndingDirectorySeparator($normalizedPath)
        }

        # handle file creation if requested
        if ($CreateFile) {

            # verify path doesn't point to existing directory
            if ([IO.Directory]::Exists($normalizedPath)) {
                throw 'Cannot create file: Path refers to an existing directory'
            }


            # create empty file if it doesn't exist
            if (-not [IO.File]::Exists($normalizedPath)) {
                $null = [IO.File]::WriteAllText($normalizedPath, '')
                Microsoft.PowerShell.Utility\Write-Verbose "Created empty file: $normalizedPath"
            }
        }

        return $normalizedPath
    }

    end {
    }
}