q attr <fnum>
 This command returns all the attribute metadata associated 
  with file number fnum in a formatted manner. If no value 
  for fnum is given, then the attributes for the default file 
  are returned. The output of 'q attr' may be read by the user in the command 
  window, or parsed by a script for the purpose of capturing the metadata and 
  including it in the analysis or display. There are three categories of attributes: 
  (1) global, which means the attribute is relevant for all the data in the file, 
  (2) coordinate, which means the attribute describes one of the four dimensions 
  (lon, lat, lev, or time), or (3) variable, which means the attribute is assoicated 
  with a particular variable in the file. The formatting of the attribute listing 
  is as follows: 
global | <dimension> | <varname> <attribute_type> <attribute_name> <attribute_value>
<dimension> is "lon", "lat", 
  "lev", or "time"
  <varname> is one of the variables in the data set
  
  <attribute_type> is one of the following case-sensitive types: 
  String, Byte, Int16, UInt16, Int32, UInt32, Float32, Float64.
  <attribute_name> is any single word or string with no spaces
  <attribute_value> is be any string up to 512 characters. 
Attributes may be native to the data file (as with some HDF 
  and NetCDF files), but they may be also be added manually in the GrADS descriptor 
  file. The output from 'q attr' will print all the attributes taken from 
  the descriptor file followed by all the native attributes. Within these two 
  categories (descriptor and native), attributes are listed in the following order:
  1. Global 
  2. Coordinate -- these will have names "lon", "lat", "lev", 
  or "time"
  3. Variable -- these will have names taken from the list of variables in the 
  data file 
This command has been fully implemented starting with version 1.9b4.
Here's a sample descriptor file (note the attributes added after the ENDVARS statement):
dset ^hgt.%y4.nc
  dtype netcdf 
  options template yrev
  title NCEP Reanalysis
  undef -999 missing_value
  unpack scale_factor add_offset
  xdef 144 linear 0 2.5
  ydef 73 linear -90 2.5
  zdef 17 levels 1000 925 850 700 600 500 400 300 250 200 150 100 70 50 30 20 
  10
  tdef 730 linear 00Z01JAN1989 1dy
  vars 1
  hgt 17 t,z,y,x Mean Daily Geopotential height [m]
  ENDVARS
  @ global String comment This is an all-purpose test file
  @ hgt String comment This describes variable hgt
  @ lev String units millibar
  @ lat String units degrees_north
  @ lon String units degrees_east
  @ time String units hours since 1-1-1 00:00:0.0
  @ lev Float32 actual_range 1000. 10.
  @ lat Float32 actual_range 90. -90.
  @ lon Float32 actual_range 0. 357.5
  @ time Int32 actual_range 17426496. 17435232.
Here's the output from 'q attr' when the above descriptor file is opened:
ga-> q attr
  Descriptor Attributes for File 1 : NCEP Reanalysis 
  global String comment This is an all-purpose test file 
  lon String units degrees_east 
  lon Float32 actual_range 0. 357.5 
  lat String units degrees_north 
  lat Float32 actual_range 90. -90. 
  lev String units millibar 
  lev Float32 actual_range 1000. 10. 
  time String units hours since 1-1-1 00:00:0.0 
  time Int32 actual_range 17426496. 17435232. 
  hgt String comment This describes variable hgt 
Native Attributes for File 1 : NCEP Reanalysis 
  global String title mean daily NMC reanalysis
  global Int16 base_date 1989 1 1 
  global String history /home/hoop/crdc/cpreanjuke2farm/cpreanjuke2farm Wed Oct 
  18 03:10:49 1995 from hgt.89.nc 
  global String history created 95/02/06 by Hoop (netCDF2.3)
  global String description Data is from NMC initialized reanalysis 
  global String description (4x/day). It consists of most variables interpolated 
  to 
  global String description pressure surfaces from model (sigma) surfaces.
  global String platform Model
  global String Conventions COARDS
  hgt String long_name mean Daily Geopotential height
  hgt Float32 actual_range -522 32306 
  hgt Float32 valid_range -700 35000 
  hgt String units m
  hgt Float32 add_offset 32066 
  hgt Float32 scale_factor 1 
  hgt Int16 missing_value 32766 
  hgt Int16 precision 0 
  hgt Int16 least_significant_digit 0 
  hgt Int16 GRIB_id 7 
  hgt String GRIB_name HGT
  hgt String var_desc Geopotential height 
  hgt String var_desc H
  hgt String dataset NCEP Reanalysis Daily Averages 
  hgt String dataset AJ
  hgt String level_desc Multiple levels 
  hgt String level_desc F
  hgt String statistic Mean