src/Get-Viewer-Less.ps1
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#!/usr/bin/env pwsh $ErrorActionPreference = "Stop" Set-StrictMode -Version Latest function Get-Viewer-Less { param( [switch] $EditingAllowed, [switch] $ReadOnly, [switch] $StayInTerminal, [switch] $TerminalWaitsUntilExit, [switch] $GuiNoWait, [switch] $AnsiPassThru, [switch] $ShowLineNumbers, [switch] $NoLineNumbers, [switch] $TextContentPlain, [switch] $TextContentSpecialCharHighlight, [switch] $TextContentSyntaxHighlight, [switch] $BinaryContentBlob, [switch] $OnlyIfHosting, [switch] $ShortPageEarlyExit, [switch] $AlwaysPages, [switch] $NeverPages, [switch] $MayUseExternalPager, [switch] $NeverUseExternalPager, [switch] $AcceptsInputPiped ) Process { if ($TerminalWaitsUntilExit -and $GuiNoWait) { throw "Cannot specify both -TerminalWaitsUntilExit and -GuiNoWait, they are mutually exclusive." } if ($ShortPageEarlyExit -and $AlwaysPages) { throw "Cannot specify both -ShortPageEarlyExit and -AlwaysPages, they are mutually exclusive." } if ($AlwaysPages -and $NeverPages) { throw "Cannot specify both -AlwaysPages and -NeverPages, they are mutually exclusive." } if ($MayUseExternalPager -and $NeverUseExternalPager) { throw "Cannot specify both -MayUseExternalPager and -NeverUseExternalPager, they are mutually exclusive." } if ($ShowLineNumbers -and $NoLineNumbers) { throw "Cannot specify both -ShowLineNumbers and -NoLineNumbers, they are mutually exclusive." } [switch[]] $alwaysDisqualifyingModifiers = @( $EditingAllowed, # $ReadOnly, # $StayInTerminal, # $TerminalWaitsUntilExit, $GuiNoWait, # $AnsiPassThru, # $ShowLineNumbers, # $NoLineNumbers, # $TextContentPlain, # $TextContentSpecialCharHighlight, $TextContentSyntaxHighlight, $BinaryContentBlob, $OnlyIfHosting, # $ShortPageEarlyExit # $AlwaysPages $NeverPages, $MayUseExternalPager # $NeverUseExternalPager, # $AcceptsInputPiped ) if ($alwaysDisqualifyingModifiers -contains $true) { if ($DebugPreference -eq "Continue") { Write-Debug "Get-Viewer-Less: Always-disqualifying modifiers used. Args: $($PSBoundParameters | ConvertTo-Json)" } return } [string[]] $argsToUse = @() [bool] $willAnsiPassThru = $false if ($AnsiPassThru -and $TextContentSpecialCharHighlight) { Write-Debug "Get-Viewer-Less: Cannot specify both -AnsiPassThru and -TextContentSpecialCharHighlight, they are mutually exclusive." return } elseif ($TextContentSpecialCharHighlight) { $willAnsiPassThru = $false } elseif ($AnsiPassThru) { $argsToUse += @("-R") $willAnsiPassThru = $true } elseif (Test-Path Env:\CLICOLOR -ErrorAction SilentlyContinue) { if ($Env:CLICOLOR) { $argsToUse += @("-R") $willAnsiPassThru = $true } } elseif ($Env:TERM_ITALICS) { $argsToUse += @("-R") $willAnsiPassThru = $true } if ($ShowLineNumbers) { $argsToUse += "--LINE-NUMBERS" } elseif ($NoLineNumbers) { $argsToUse += "--line-numbers" } if ($ShortPageEarlyExit -and $TerminalWaitsUntilExit) { Write-Debug "Get-Viewer-Less: Cannot specify both -ShortPageEarlyExit and -TerminalWaitsUntilExit, they are mutually exclusive." return } elseif ($ShortPageEarlyExit) { $argsToUse += "--quit-if-one-screen" } $argsToUse += "--mouse" [System.Collections.Immutable.ImmutableDictionary[string,string]] $binEnv = [System.Collections.Immutable.ImmutableDictionary[string,string]]::Empty [string] $less_bin = (Search-CommandPathMemoized "less") if ($less_bin) { [string] $invocationSignature = (Get-InvocationSignature $less_bin @argsToUse) $argsToUse = [System.Collections.Immutable.ImmutableList]::Create($argsToUse) [PSCustomObject]@{ Id = "less#${invocationSignature}"; Name = "less"; Bin = $less_bin; BinArgs = $argsToUse; AcceptsInputPiped = $true; AlwaysPages = (-not $ShortPageEarlyExit); NeverPages = $false; ShortPageEarlyExit = [bool]$ShortPageEarlyExit; MayPage = $true; MayUseExternalPager = $false; NeverUsesExternalPager = $true; TerminalWaitsUntilExit = (-not $ShortPageEarlyExit) AnsiPassThru = $willAnsiPassThru; ShowLineNumbers = ([bool]$ShowLineNumbers -or (-not $NoLineNumbers)); BinEnv = $binEnv; } | Write-Output } else { Write-Debug "Get-Viewer-Less: No 'less' binary found." } } } |