Blacklist lines from a .txt file

[andreiem]

My script use 1 line from a txt file called user.txt every few minutes. I'm looking to save the used line to blacklist.txt file and when script go to the next line, it should check in the blacklist.txt if the line exist. If exist then it should ignore it and move to the next line.

Thanks for any help

[tet-vivi]

@andreiem run the code

while ( true ) {
  [[USER]] = {{user|notreuse}};
  if( RMap( "blacklist" ).indexOf( [[USER]] ) != -1 ) break;
}

{{user}} - file resource user.txt
"blacklist" - file resource name blacklist.txt

in [[USER]] will be something that is not in blacklist.txt.