pro dustem_show_sysvar,file=fileif keyword_set(file) then OPENW, 2, filehelp,/sys,out=sysvarfori=0,n_elements(sysvar)-1do begin this_line=strsplit(sysvar[i],"!",/ext)forj=0,n_elements(this_line)-1do beginprint,"!"+this_line[j]if keyword_set(file) then printf,2,"!"+this_line[j]endforendforif keyword_set(file) then close, 2end