CODEWITHSUNDEEP
powershell
BeCAN
BeCAN

Reputation: 11

Erase a line if the previous line doesn't match?

First of all, sorry for my bad English...I'm a native Spanish speaker...

Well, my question is that I have a .m3u file with a bunch of iptv channels url that look like this:

#EXTINF:-1,Discovery ID FHD (E)

http://url/name/password/46562

http://url/name/password/465621 (need to erase)

#EXTINF:-1,Discovery H&H FHD  (E)

http://url/name/password/46563

http://url/name/password/46564 (need to erase)

http://url/name/password/46565 (need to erase)

http://url/name/password/465651 (need to erase)

http://url/name/password/465652 (need to erase)

#EXTINF:-1,Discovery Theater FHD (E)

http://url/name/password/46566 (need to erase)

#EXTINF:-1,Discovery Theater FHD (E)(2)

http://url/name/password/46567

There is a header line with a name (#EXTINF CHANNELNAME) before the URL with the channel (HTTP://URL/NAME/PASSWORD/NUMBER/)

Is there any way to erase the (need to erase) lines with PowerShell? I need that any lines without a preceding #EXTINF line to be deleted. I need to do this because all the kodi iptv adoon won't recognize the file if it has lines without a preceding #EXTINF line.

Upvotes: 1

Views: 102

Answers (3)

mklement0
mklement0

Reputation: 437090

You can use Select-String with the -Context parameter:

  • Note: I'm assuming that the empty lines between your sample lines are just posting artifacts; if there truly is an empty line after each line starting with #EXTINF:, replace -Context 0, 1 with -Context 0, 2.
# Extract the lines of interest from file 'in.m3u'
# and save them to file 'out.m3u'
Select-String '^#EXTINF:' in.m3u -Context 0, 1 | 
  ForEach-Object{ $_.Line; $_.Context.PostContext } |
    Set-Content out.m3u

Upvotes: 0

Theo
Theo

Reputation: 61028

You could use switch for this to delete the unwanted lines at high speed:

$m3uFileIn   = 'D:\Test\FileToProcess.m3u'     # the full path and filename of the original .m3u file
$m3uFileOut  = 'D:\Test\FileAsItShouldBe.m3u'  # this can be the same as $m3uFileIn if you want to overwrite it
$foundExtInf = $false
# parse the file and return only lines starting with '#EXTINF' 
# and the first subsequent non-blank line, 
# and collect these lines in variable $linesToKeep
$linesToKeep = switch -Regex -File $m3uFileIn {
    '^#EXTINF:'  { $_ ; $foundExtInf = $true; continue }
    '\S'         { if ($foundExtInf) { $_ ; $foundExtInf = $false} }
}

# save as (new) file. parameter -PassThru also outputs to console
$linesToKeep -join "`r`n`r`n" | Set-Content -Path $m3uFileOut -Force -PassThru

Output:

#EXTINF:-1,Discovery ID FHD (E)

http://url/name/password/46562

#EXTINF:-1,Discovery H&H FHD  (E)

http://url/name/password/46563

#EXTINF:-1,Discovery Theater FHD (E)

http://url/name/password/46566 (need to erase)

#EXTINF:-1,Discovery Theater FHD (E)(2)

http://url/name/password/46567

P.S. This will finalize the file with an empty line appended to it. If you don't want that, add the -NoNewline switch to the Set-Content cmdlet

Upvotes: 2

Daniel
Daniel

Reputation: 5114

# Change iptv.txt file to your file
$data = Get-Content ".\iptv.txt"

$pattern = '^#EXTINF'

$enum = $data.GetEnumerator()
$keep = [System.Collections.ArrayList]::new()

$enum.MoveNext() | Out-Null
while ($enum.Current) {
    if ($enum.Current -match $pattern) {
        $keep.Add($enum.Current) | Out-Null
        $count = 0
        $enum.MoveNext() | Out-Null
        do {
            if (![string]::IsNullOrWhiteSpace($enum.Current) -and $enum.Current -notmatch $pattern ) {
                if ($count -lt 1) { $keep.Add($enum.Current) | Out-Null; $count++ }
            }
        } until($enum.Current -match $pattern -or -not $enum.MoveNext())
    }
    else {
        $keep.Add($enum.Current) | Out-Null
        $enum.MoveNext() | Out-Null
    }
}

$keep | ForEach-Object {$_ + "`n"} | Out-File ".\revised_data.txt"

New data

#EXTINF:-1,Discovery ID FHD (E)

http://url/name/password/46562

#EXTINF:-1,Discovery H&H FHD  (E)

http://url/name/password/46563

#EXTINF:-1,Discovery Theater FHD (E)

http://url/name/password/46566 (need to erase)

#EXTINF:-1,Discovery Theater FHD (E)(2)

http://url/name/password/46567

Upvotes: 0

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