rcs: Environment

 
 2.1.10 Environment
 ------------------
 
 Various environment variables influence how RCS works.
 
  -- Environment Variable: RCSINIT
      Another way to set common options is with the ‘RCSINIT’ environment
      variable.  This is a space-separated list of options.  Use ‘\’
      (backslash) to escape significant space.  For example:
 
           # Set the value; make it available to subsequent commands.
           RCSINIT="-q -x/,v -zLT"
           export RCSINIT
 
           # Use it (implicitly).
           rlog -L foo
 
      This example, in Bourne shell syntax, arranges for RCS commands to
      operate as if each command-line had prepended ‘-q -x/,v -zLT’ to
      the rest of the command-line.  The effective command-line that rlog
      sees is thus ‘-q -x/,v -zLT -L foo’.
 
  -- Environment Variable: RCS_MEM_LIMIT
      Normally, for speed, commands either memory map or copy into memory
      the RCS file if its size is less than the “memory limit”, currently
      defaulting to “unlimited”.  Otherwise (or if the initially-tried
      speedy ways fail), the commands fall back to using standard i/o
      routines.
 
      You can adjust the memory limit by setting the ‘RCS_MEM_LIMIT’
      environment variable to a numeric value (measured in kilobytes).
      An empty value is silently ignored.
 
      As a side effect, specifying the memory limit inhibits fall-back to
      slower routines.  (This env var is mostly intended for testing RCS;
      normally, you can leave it unset.  Probably it will be removed in a
      future release.)
 
  -- Environment Variable: TMPDIR
  -- Environment Variable: TMP
  -- Environment Variable: TEMP
      Commands sometimes create temporary files, normally in a
      system-dependent directory, such as ‘/tmp’.  You can override this
      directory by specifying another one as the value of one of the
      environment variables ‘TMPDIR’, ‘TMP’, or ‘TEMP’ (checked in that
      order).
 
  -- Environment Variable: LOGNAME
  -- Environment Variable: USER
      Absent ‘-wLOGIN’, or when LOGIN is omitted (⇒Misc common
      options), commands check environment variables ‘LOGNAME’ and
      ‘USER’ in that order(1).  If neither of these are set, RCS queries
      the host for, and uses, your login.
 
    ---------- Footnotes ----------
 
    (1) However, on systems where env var ‘LOGNAME’ is readonly at
 configure time, RCS checks ‘USER’ first.