FUNCTION n_lines,file

; This function opens the specified file, determines its length in
; bytes, and reads it in as a BYTE-valued array.  It then returns
; the number of occurrences of 10B in the file.  10B is the ASCII
; code for a line feed, which marks the end of a line of text (in
; UNIX, at least).

; Modified 10 January 1995 by D P Steele:
; If called under VMS, this function dodges the whole issue of
; counting lines and SPAWNs a call to WC.COM, which uses EVE (the
; Extensible Vax Editor) to count the number of lines and return
; the result.  Obviously, WC.COM must be accessible to the function.

f=RFindFile(file,Count=nf)
IF nf EQ 0 THEN BEGIN
    Message,file+' not found!',/INFORMATIONAL
    Return,-1
    ENDIF
    
IF !VERSION.OS EQ 'vms' THEN BEGIN
    SPAWN,'@USER$:[STEELE.IDL]WC '+file,n
    n=LONG(n(0))
    ENDIF ELSE BEGIN
    OPENR,unit,file,/GET_LUN
    f=FSTAT(unit)
    IF f.SIZE EQ 0 THEN n=0L ELSE BEGIN
        b=BYTARR(f.size)
        READU,unit,b
        n=LONG(TOTAL(b EQ 10B))
        ENDELSE
    FREE_LUN,unit
    ENDELSE

RETURN,n
END