CDO

v1.9.7

cdo -v -f grb copy infile outfile

wgrib showed the variables as being these, which I don't think is right for attachment:

PRES=Pressure [Pa]
  PRMSL=Pressure reduced to MSL [Pa]
  PTEND=Pressure tendency [Pa/s]
  PVORT=Pot. vorticity [km^2/kg/s]
  ICAHT=ICAO Standard Atmosphere Reference Height [M]
  GP=Geopotential [m^2/s^2]
  HGT=Geopotential height [gpm]
  DIST=Geometric height [m]
  HSTDV=Std dev of height [m]
  TOZNE=Total ozone [Dobson]
  TMP=Temp. [K]
  VTMP=Virtual temp. [K]
  POT=Potential temp. [K]
  EPOT=Pseudo-adiabatic pot. temp. [K]
  TMAX=Max. temp. [K]
  TMIN=Min. temp. [K]
  DPT=Dew point temp. [K]
  DEPR=Dew point depression [K]
  LAPR=Lapse rate [K/m]
  VIS=Visibility [m]
  RDSP1=Radar spectra (1) [non-dim]
  RDSP2=Radar spectra (2) [non-dim]
  RDSP3=Radar spectra (3) [non-dim]
  PLI=Parcel lifted index (to 500 hPa) [K]
  TMPA=Temp. anomaly [K]
  PRESA=Pressure anomaly [Pa]
  GPA=Geopotential height anomaly [gpm]
  WVSP1=Wave spectra (1) [non-dim]
  WVSP2=Wave spectra (2) [non-dim]
  WVSP3=Wave spectra (3) [non-dim]
  WDIR=Wind direction [deg]
  WIND=Wind speed [m/s]
  UGRD=u wind [m/s]
  VGRD=v wind [m/s]
  STRM=Stream function [m^2/s]
  VPOT=Velocity potential [m^2/s]

It also had this message: "Undefined parameter table (center 0-0 table 255), using NCEP-opn" which I think means it couldn't find the parameter look-up table.