path for filewriter?

[Chris_C]

without a path (just a filename) not surprisingly I get an error !

how do I get a path I'm "supposed" to use?

do I need to ensure a directory is created (inside plugindata ?)

IOException: Sharing violation on path /home/chris/.local/share/Steam/SteamApps/common/Kerbal Space Program/PluginData/mscorlib/map.csv
  at System.IO.FileStream..ctor (System.String path, FileMode mode, FileAccess access, FileShare share, Int32 bufferSize, Boolean anonymous, FileOptions options) [0x00000] in <filename unknown>:0 
  at System.IO.FileStream..ctor (System.String path, FileMode mode, FileAccess access, FileShare share) [0x00000] in <filename unknown>:0 
  at System.IO.StreamWriter..ctor (System.String path, Boolean append, System.Text.Encoding encoding, Int32 bufferSize) [0x00000] in <filename unknown>:0 
  at System.IO.StreamWriter..ctor (System.String path) [0x00000] in <filename unknown>:0 
  at KSP.IO.TextWriter.CreateForType[String] (System.String filename, .Vessel flight) [0x00000] in <filename unknown>:0 

TIA

[EndlessWaves]

No, the directory is determined by the assembly name of the class you feed TextWriter on initialisation.

Sharing violation sounds like you've either got it open in another application or you're accidentally opening multiple streams on the same file at the same time (you can use multiple streams sequentially as long as you Close() one before opening another).