SUBROUTINE unixfi(f1,f2)

C-----------------------------------------------------------------------
C  unixfi : convert VMS file spec to unix path; treat logical names as
C           environment variables
C  author : Morgan Burke (TRIUMF)
C  date   : 1992-June-02
C-----------------------------------------------------------------------

$$IMPLICIT

      CHARACTER*(*) f1,f2
      CHARACTER*132 Lower_Case,trans
      CHARACTER*40  env,Upper_Case
      INTEGER*4 indx,dindx,Lensig,lf1

C  make sure f1 isn't already a valid unix path

      f2 = f1
      IF (INDEX(f1,'/') .GT. 0) RETURN
      lf1 = Lensig(f1)

C  find logical name

      indx = INDEX(f1,':')
      IF (indx .EQ. 0) indx = lf1 + 1
      env = Upper_Case(f1(1:indx-1))

C  replace dollar signs with underscores

      dindx = INDEX(env,'$')
      IF (dindx .GT. 0) env(dindx:dindx) = '_'

C  compose the full unix path

      CALL Getenv(env,trans)
      IF (indx .LT. lf1) THEN
	f2 = trans(1:Lensig(trans)) // '/' // Lower_Case(f1(indx+1:))
      ELSE IF (trans .NE. ' ') THEN
	f2 = trans
      ENDIF
      RETURN
      END