ver and mklink $profile functions

ver_and_mklink.ps1

function ver_windows {
    $osver = [environment]::osversion.version
    $major = $osver.major
    $build = $osver.build

    if ($major -eq 10 -and $build -gt 22000) {
        $major = 11
    }

    try {
        $arch = [System.Runtime.InteropServices.RuntimeInformation,mscorlib]::OSArchitecture
    } catch {}

    'Windows {0} build {1}{2}' `
        -f $major,
           $build,
           $(if ($arch) { " $arch" })
}

function global:ver {
    if ($iswindows) {
        ver_windows
    }
    else {
        $uname_parts = $(if     ($islinux) { 'sri' }
                         elseif ($ismacos) { 'srm' }
                       ).getenumerator() | %{ uname "-$_" }

        # Remove -xxx-xxx suffixes from kernel versions.
        if ($islinux) {
            $uname_parts[1] = $uname_parts[1] -replace '-.*',''
        }

        "{0} kernel {1} {2}" -f $uname_parts
    }
}

function global:mklink {
    $usage = 'args: [link] target'

    $args = $args | %{ $_ } | ? length

    if (-not $args) { $args = @($input) }

    while ($args.count -gt 2 -and $args[0] -match '^/[A-Z]$') {
        $null,$args = $args
    }

    if (-not $args -or $args.count -gt 2) {
        write-error $usage -ea stop
    }

    $link,$target = $args

    if (-not $target) {
        $target = $link

        if (-not (split-path -parent $target)) {
            write-error ($usage + "`n" + 'cannot make link with the same name as target') -ea stop
        }

        $link = split-path -leaf $target
    }

    if (-not ($link_parent = split-path -parent $link)) {
        $link_parent = get-location | % path
    }
    if (-not ($target_parent = split-path -parent $target)) {
        $target_parent = get-location | % path
    }

    $link_parent = try {
        $link_parent | resolve-path -ea stop | % path
    }
    catch { write-error $_ -ea stop }

    if (-not (resolve-path $target -ea ignore)) {
        write-warning "target '${target}' does not yet exist"
    }

    $absolute = @{
        link   = join-path $link_parent   (split-path -leaf $link)
        target = join-path $target_parent (split-path -leaf $target)
    }

    $home_dir_re = [regex]::escape($home)
    $dir_sep_re  = [regex]::escape($dir_sep)

    $in_home = @{}

    $absolute.getenumerator() | %{
      if ($_.value -match ('^'+$home_dir_re+"($dir_sep_re"+'|$)')) {
        $in_home[$_.key] = $true
      }
    }

    # If target is in home, make sure ~ is resolved.
    #
    # Make sure relative links are relative to link parent
    # (::ispathrooted() does not understand ~ paths and considers
    # them relative.)
    #
    # And if both link and target are in home dir, force relative
    # link, this is to make backups/copies/moves and SMB shares of
    # the home/profile dir easier and less error-prone.
    $target = if (-not (
                      $in_home.target `
                      -or [system.io.path]::ispathrooted($target)
                  ) -or $in_home.count -eq 2) {

        pushd $link_parent
        resolve-path -relative $absolute.target
        popd
    }
    else {
        $absolute.target
    }

    if (-not $iswindows -or $psversiontable.psversion.major -ge 6) {
        # PSCore.
        try {
            new-item -itemtype symboliclink $absolute.link `
                -target $target -ea stop
        }
        catch { write-error $_ -ea stop }
    }
    else {
        # WinPS or older.
        $params = @(
            if (test-path -pathtype container $target) { '/D' }
        )
        cmd /c mklink @params $absolute.link $target
        if (-not $?) { write-error "exited: $LastExitCode" -ea stop }
    }
}

function global:rmlink {
    $args = @($input),$args | %{ $_ } | ? length

    if (-not $args) {
        write-error 'args: link1 [link2 ...]' -ea stop
    }

    $args | %{
        try { $_ = gi $_ -ea stop }
        catch { write-error $_ -ea stop }

        if (-not $_.target) {
            write-error "$_ is not a symbolic link" -ea stop
        }

        if ((test-path -pathtype container $_) `
            -and $iswindows `
            -and $psversiontable.psversion.major -lt 7) {

            # In WinPS remove-item does not work for dir links.
            cmd /c rmdir $_
            if (-not $?) { write-error "exited: $LastExitCode" -ea stop }
        }
        else {
            try { ri $_ }
            catch { write-error $_ -ea stop }
        }
    }
}