/*!  \page grib_ls grib_ls
\section DESCRIPTION 
 List content of grib files printing values of some keys.
	It does not fail when a key is not found.

\section USAGE 
 grib_ls 
 [options] grib_file grib_file ...

\section OPTIONS 
-p key[:{s/d/i}],key[:{s/d/i}],... \n 
		Declaration of keys to print.
		For each key a string (key:s), a double (key:d) or an integer (key:i)
		type can be requested. Default type is string.
 \n \n -F format \n 
		C style format for floating point values.
 \n \n -P key[:{s/d/i}],key[:{s/d/i}],... \n 
		As -p adding the declared keys to the default list.
 \n \n -w key[:{s/d/i}]{=/!=}value,key[:{s/d/i}]{=/!=}value,... \n 
		Where clause.
		Messages are processed only if they match all the key/value constraints.
		A valid constraint is of type key=value or key!=value.
		For each key a string (key:s), a double (key:d) or an integer (key:i)
		type can be specified. Default type is string.
 \n \n -j  \n json output
 \n \n -B order by directive \n 
		Order by. The output will be ordered according to the order by directive.
		Order by example: "step:i asc, centre desc" (step numeric ascending and centre descending)
 \n \n -l Latitude,Longitude[,MODE,file] \n 
		Value close to the point of a Latitude/Longitude.
		Allowed values for MODE are:
		4 (4 values in the nearest points are printed) Default
		1 (the value at the nearest point is printed)
		file (file is used as mask. The closer point with mask value>=0.5 is printed)
 \n \n -s key[:{s/d/i}]=value,key[:{s/d/i}]=value,... \n 
		Key/values to set.
		For each key a string (key:s), a double (key:d) or an integer (key:i)
		type can be defined. By default the native type is set.
 \n \n -i index \n 
		Data value corresponding to the given index is printed.
 \n \n -n namespace \n 
		All the keys belonging to namespace are printed.
 \n \n -m  \n Mars keys are printed.
 \n \n -V  \n Version.
 \n \n -W width \n 
		Minimum width of each column in output. Default is 10.
 \n \n -M  \n Multi-field support off. Turn off support for multiple fields in single grib message.
 \n \n -g  \n Copy GTS header. 
 \n \n -T T | B | M | A \n Message type. T->GTS, B->BUFR, M->METAR (Experimental),A->Any (Experimental).
			The input file is interpreted according to the message type.
 \n \n -7  \n Does not fail when the message has wrong length
 \n \n -X offset \n 
		Input file offset in bytes. Processing of the input file will start from "offset".
 \n \n -x  \n Fast parsing option, only headers are loaded.
 \n \n 
\section grib_ls_examples grib_ls examples
-# Without options a default list of keys is printed. \n
The default list is different depending on the type of grib message. \n
\verbatim 
> grib_ls ../data/reduced*.grib1 ../data/regular*.grib1 ../data/reduced*.grib2 \n
\endverbatim\n 
-# To print offset and count number in file use the keys offset and count\n 
Also the total count in a set of files is available as countTotal\n
\verbatim 
> grib_ls -p offset,count,countTotal ../data/reduced*.grib1
\endverbatim\n 
-# To list only a subset of messages use the -w (where option).\n 
Only the pressure levels are listed with the following line.\n 
\verbatim 
> grib_ls -w levelType=pl ../tigge_pf_ecmwf.grib2 
\endverbatim\n 
-# All the grib messages not on pressure levels are listed as follows:\n 
\verbatim 
> grib_ls -w levelType!=pl ../tigge_pf_ecmwf.grib2 
\endverbatim\n 
-# To get the closest grid point to a latitude/longitude.\n
\code 
>grib_ls -l 51.46,-1.33,1 -p paramId,name ../data/reduced_gaussian_surface.grib2
../data/reduced_gaussian_surface.grib2
paramId     shortName    value 
167         2t          282.002     
1 of 1 messages in ../data/reduced_gaussian_surface.grib2

1 of 1 total messages in 1 files
Input Point: latitude=51.46  longitude=-1.33
Grid Point chosen #3 index=749 latitude=51.63 longitude=0.00 distance=93.81 (Km)
Other grid Points
- 1 - index=845 latitude=48.84 longitude=0.00 distance=306.86 (Km)
- 2 - index=944 latitude=48.84 longitude=356.40 distance=333.66 (Km)
- 3 - index=749 latitude=51.63 longitude=0.00 distance=93.81 (Km)
- 4 - index=844 latitude=51.63 longitude=356.25 distance=168.37 (Km)
\endcode\n
*/