Example 9. Convert multiple files into single 64-bit netCDF4 file using CF metadata

#! /usr/bin/env convsh

#  Convsh script conv2nc_cf.tcl
#
#  Convert input files into single netCDF4 file with CF metadata.
#  All input files must contain the same fields and have
#  identical dimensions except for the time dimension.
#  For example to convert UM output files into a netCDF file
#  use the following command:
#
#      conv2nc_cf.tcl -i xaavaa.pc* -o xaava.nc

#  Use CF compatible netCDF attributes + useful others
setvaratt all att_nouse
setvaratt north_pole standard_name att_cond
setvaratt long_name units missing_value _Fillvalue valid_min valid_max att_use
setdimatt all att_nouse
setdimatt standard_name calendar att_cond
setdimatt long_name units axis time_origin positive att_use

#  Set netCDF global attribute Conventions
setglobatt Conventions att_use
writeglobatt Conventions "CF-1.5"

#  Use STASH code to get UM variable long names
set umlong 1

#  Write out netCDF file
set outformat netcdf
#  Set netCDF format to be netCDF4 classic model
set ncoformat 2
# Set netCDF precision to 64 bit
set ncprec 64

#  Automatically work out input file type
set filetype 0

#  Convert all fields in input files to netCDF
set fieldlist -1

#  Get command line arguments:
#      -i input files (can be more than one file)
#      -o output file (single file only)

set i false
set o false
foreach arg $argv {
   switch -glob -- $arg {
      -i      {set i true ; set o false}
      -o      {set i false ; set o true}
      -*      {puts "unknown option $arg" ; set i false; set o false}
      default {
         if {$i} {example9.rst
            set infile [lappend infile $arg]
         } elseif {$o} {
            set outfile [lappend outfile $arg]
         } else {
            puts "unknown option $arg"
         }
      }
   }
}

if {! [info exists infile]} {
   puts "input file name must be given"
   exit
}

if {[info exists outfile]} {
   if {[llength $outfile] > 1} {
      set outfile [lindex $outfile 0]
      puts "Only one output file can be specified, using $outfile"
   }
} else {
   puts "output file name must be given"
   exit
}

#  Read in each of the input files

foreach file $infile {
   readfile $filetype $file
}

#  Write out all input fields to a single netCDF file

writefile $outformat $outfile $fieldlist