Codex
36 lines
1.8 KiB
PowerShell
36 lines
1.8 KiB
PowerShell
if ($operation -in @('head', 'tail')) {
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$linesWanted = 10; $paths = [Collections.Generic.List[string]]::new()
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for ($i = 0; $i -lt $toolArgs.Count; $i++) {
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$arg = $toolArgs[$i]
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if ($arg -in @('-n', '--lines')) { $i += 1; if ($i -ge $toolArgs.Count) { Fail ($arg + ' requires a value') 2 }; $linesWanted = Parse-NonNegativeInt $arg $toolArgs[$i] 10000; continue }
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if ($arg.StartsWith('-n') -and $arg.Length -gt 2) { $linesWanted = Parse-NonNegativeInt '-n' $arg.Substring(2) 10000; continue }
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if ($arg.StartsWith('--lines=')) { $linesWanted = Parse-NonNegativeInt '--lines' $arg.Substring(8) 10000; continue }
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if ($arg -match '^-(\d+)$') { $linesWanted = Parse-NonNegativeInt ('-' + $Matches[1]) $Matches[1] 10000; continue }
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if ($arg.StartsWith('-') -and $arg -ne '-') { Fail ('unsupported ' + $operation + ' option on Windows route: ' + $arg) 2 }
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$paths.Add($arg)
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}
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if ($paths.Count -ne 1) { Fail ($operation + ' requires exactly one file path on Windows routes') 2 }
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$resolved = Resolve-UnideskPath $paths[0]
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Need-File $resolved
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$selected = [Collections.Generic.List[string]]::new()
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$reader = [IO.StreamReader]::new($resolved, [Text.UTF8Encoding]::new($false, $true), $true)
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try {
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if ($operation -eq 'head') {
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while ($selected.Count -lt $linesWanted -and -not $reader.EndOfStream) { $selected.Add($reader.ReadLine()) }
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} else {
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$queue = [Collections.Generic.Queue[string]]::new()
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while (-not $reader.EndOfStream) {
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$queue.Enqueue($reader.ReadLine())
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if ($queue.Count -gt $linesWanted) { [void]$queue.Dequeue() }
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}
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foreach ($line in $queue) { $selected.Add($line) }
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}
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} catch {
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Fail ('file is not valid UTF-8: ' + $resolved + ': ' + $_.Exception.Message) 25
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} finally {
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$reader.Dispose()
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}
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Print-Lines ([string[]]$selected)
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exit 0
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}
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