GrADS  V1.6.beta4                                               1

gribscan(1)             GrADS  V1.6.beta4             gribscan(1)

NAME
     gribscan - GrADS extract grid info from GRIB data files.

SYNOPSIS
     gribscan [ -i fname ] [-o ofname ] [ -og ] [ -oa ] [ -of ]

DESCRIPTION
     gribscan is a GrADS routine which  is  used  for  extracting
     grid info from a GRIB data file or features:

              grid output in ASCII, floats, and/or grib;

              product/grid information;

              automatic scanning for GRIB records  so  that  you
               don't have to know the physical layout of the data
               to scan it;

FILE OPTIONS
     -i fname       fname is the input grib file name.

     -o ofname      ofname is the output  file  name  WITHOUT  an
                    extension.

     -og            output GRIB.

     -oa            output ASCII.

     -of            a stream of floats. This is machine dependent
                    and  is  equal  to  64bit on CRAYS and 32-bit
                    elsewhere.

     If -i option is not invoked then gribscan asks  for  a  file
     name.  If  -o  option  is  omitted  then a default ofname of
     zy0x1w2.type is created where type is equal to

     asc  ASCII

     grb  GRIB

     dat  a stream of floats (GrADS format)

DISPLAY OPTIONS
     -q             quick output to extract stuff  GrADS  gribmap
                    cares about.

     -q1            one-line quick output.

     -d             common delimited mode.

     -v             verbose mode for diagnostics.

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gribscan(1)             GrADS  V1.6.beta4             gribscan(1)

     -bd            binary data section info.

     -gv            use the NMC GRIB variable table to output the
                    mnemonic,  title  and units from the standard
                    NMC table.

     -gd            output info from the grid defined section.

     -h81           needed for old "standard" NMC GRIB file  with
                    81-byte header.

     -S             silent NO standard output.

EXAMPLES
     Example 1:

          A "quick" scan to get the info GrADS cares about:

          gribscan -q -i eta.T12Z.PGrbF48 | grep 184

          produces the following line:

          184,F,135,108,100,0,100,0,1e+09,T,1994,8,29,12,0,1,48,0,
          G,104,BDTG,94082912

          184        -   field # in the file
          F          -   field data
          135        -   param #
          108        -   level indicator
          100        -   level
          0          -   11 byte 1 of level
          100        -   12 byte 2 of level
          0          -   time range indicator
          1e+09      -   decimal scale factor
          T          -   time data follows
          1994       -   year
          8          -   month
          29         -   day
          12         -   hour
          0          -   min
          1          -   forecast time unit (hour)
          48         -   t=48 h forecast
          G          -   grid param follows
          104        -   NMC grid #104
          BDTG       -   Base date-time-group (yymmddhh) follows
          94082912   -   yymmddhh

     Example 2:

          Comma delimited output for parsing by things like awk:

          gribscan -d -i eta.T12Z.PGrbF48 | grep 184

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gribscan(1)             GrADS  V1.6.beta4             gribscan(1)

          produces the following line:

          PDS,184,104,135,108,100,0,100,1994,8,29,12,0,1,48,0,0,1e+09

          same as above but arranged differently.

     Example 3:

          A full listing:

          gribscan -d -gv -bd -gd -i eta.T12Z.PGrbF48 | grep 184

          produces the following line:

          PDS,184,104,135,108,100,0,100,1994,8,29,12,0,1,1e+09,mconv,
          Horizontal moisture divergence,[kg/kg/s],GDS,5,147,110,
          -139.475,90.755,0.354,-0.268,-105.000,3353.000,0,1,0,BDS,12,
          -646.844,16170,4825059,26366

          104        -   grid id
          param #135 -   mconv, Horizontal moisture divergence,
                         [kg/kg/s] (shown by -gv option)
          BDS        -   binary data section
          646.844    -   reference value
          16170      -   # of points
          4825059    -   starting byte of the data
          26366      -   length of the grib message

     Example 4:

          Output a selected few fields in GRIB:

          gribscan -og -sp135 -q -i eta.T12Z.PGrbF48 -o /wrk/$USER/eta.135

          Writes out all GRIB message containing the 135  parame-
          ter to the file /wrk/$USER/tmp/eta.135.grb.

     A subsequent gribscan on eta.135.grb:

          gribscan -q -i eta.135.grb

          produces the following line:

          1,F,135,108,100,0,100,0,1e+09,T,1994,8,29,12,0,1,48,0,G,104,
          BDTG,94082912, 2,F,135,108,21860,85,100,0,1e+09,T,
          1994,8,29,12,0,1,48,0,G,104,BDTG,94082912

SEE ALSO
     grads(1), gribmap(1)
     - GrADS Documentation V1.5.1.12 (gadoc151.ps),
         Brian Doty (COLA), Mike Fiorino (LLNL), Tom Holt (UEA)
     - GrADS commands and scripting language reference cards,

GrADS  V1.6.beta4         Last change:                          3

gribscan(1)             GrADS  V1.6.beta4             gribscan(1)

         Karin Meier (DKRZ)

GrADS  V1.6.beta4         Last change:                          4