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 (require mzlib/os)

Returns a string for the current machine’s hostname (including its domain).

Returns an integer identifying the current process within the operating system.

(truncate-file file [n-bytes])  void?
  file : path-string?
  n-bytes : exact-nonnegative-integer? = 0
Truncates or extends the given file so that it is n-bytes long. If the file does not exist, or if the process does not have sufficient privilege to truncate the file, the exn:fail exception is raised.

WARNING: on Unix, the implementation assumes that the platform’s ftruncate function accepts a long long second argument.