How do you enable powershell to interpret ansi color codes when using get-content to echo to the screen?

Question

I have a log file that contains ansi color codes around various text. I'm echoing it to the console using the powershell language command:

get-content logfile.log -wait

so I can see the latest log changes. However, all the ansi color codes show up as text characters like:

 Esc[90mEsc[39m

How do you get them intepreted as color codes in the powershell window?

Not being very familiar with the powershell language yet, is there a powershell command or encoding option to handle this? I've read various powershell docs but haven't found anything in them re these ansi codes.

Answer 1

You can translate the ANSI escape codes for colors by splitting the text at ESC and translating the colors into Write-Host .... -Forground <color> instructions.

function Open-Colored([String] $Filename)
  { Write-Colored(cat -Raw $Filename) }

function Write-Colored([String] $text)
  { # split text at ESC-char
    $split = $text.Split([char] 27)
    foreach ($line in $split)
      { if ($line[0] -ne '[')
          { Write-Host $line -NoNewline }
        else
          { if     (($line[1] -eq '0') -and ($line[2] -eq 'm')) { Write-Host $line.Substring(3) -NoNewline }
            elseif (($line[1] -eq '3') -and ($line[3] -eq 'm'))
              { # normal color codes
                if     ($line[2] -eq '0') { Write-Host $line.Substring(4) -NoNewline -ForegroundColor Black       }
                elseif ($line[2] -eq '1') { Write-Host $line.Substring(4) -NoNewline -ForegroundColor DarkRed     }
                elseif ($line[2] -eq '2') { Write-Host $line.Substring(4) -NoNewline -ForegroundColor DarkGreen   }
                elseif ($line[2] -eq '3') { Write-Host $line.Substring(4) -NoNewline -ForegroundColor DarkYellow  }
                elseif ($line[2] -eq '4') { Write-Host $line.Substring(4) -NoNewline -ForegroundColor DarkBlue    }
                elseif ($line[2] -eq '5') { Write-Host $line.Substring(4) -NoNewline -ForegroundColor DarkMagenta }
                elseif ($line[2] -eq '6') { Write-Host $line.Substring(4) -NoNewline -ForegroundColor DarkCyan    }
                elseif ($line[2] -eq '7') { Write-Host $line.Substring(4) -NoNewline -ForegroundColor Gray        }
              }
            elseif (($line[1] -eq '3') -and ($line[3] -eq ';') -and ($line[5] -eq 'm'))
              { # bright color codes
                if     ($line[2] -eq '0') { Write-Host $line.Substring(6) -NoNewline -ForegroundColor DarkGray    }
                elseif ($line[2] -eq '1') { Write-Host $line.Substring(6) -NoNewline -ForegroundColor Red         }
                elseif ($line[2] -eq '2') { Write-Host $line.Substring(6) -NoNewline -ForegroundColor Gree        }
                elseif ($line[2] -eq '3') { Write-Host $line.Substring(6) -NoNewline -ForegroundColor Yellow      }
                elseif ($line[2] -eq '4') { Write-Host $line.Substring(6) -NoNewline -ForegroundColor Blue        }
                elseif ($line[2] -eq '5') { Write-Host $line.Substring(6) -NoNewline -ForegroundColor Magenta     }
                elseif ($line[2] -eq '6') { Write-Host $line.Substring(6) -NoNewline -ForegroundColor Cyan        }
                elseif ($line[2] -eq '7') { Write-Host $line.Substring(6) -NoNewline -ForegroundColor White       }
              }
          }
      }
  }

Usage:

Open-Colored .\myColoredLogfile.log