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The verb list queries the MARS archive about the data availability for a given request. It is suitable for interactive or batch use to check availability of certain datasets and its collocation in the archive.

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If the keyword output=browser is used, the list output will contain the same information as given by Web-MARS when browsing the catalogue. In other words, the archive MARS content can be browsed from the command line as shown in the following example where the request

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class=cs
class=dm
class=dt
class=e4
class=ei,stream=mdfa
class=ei,stream=mnth
class=ei,stream=moda,expver=1,type=an,levtype=ml
class=ei,stream=moda,expver=1,type=an,levtype=pl
class=ei,stream=moda,expver=1,type=an,levtype=pt
class=ei,stream=moda,expver=1,type=an,levtype=pv
class=ei,stream=moda,expver=1,type=an,levtype=sfc
class=ei,stream=moda,expver=1,type=fc
class=ei,stream=moda,expver=1112
class=ei,stream=oper
class=ei,stream=wave
class=el
class=en
class=er
class=me
class=pv
class=to

If the keyword output=cost is used, the list output will generate a summary of the size, number of fields and the storage information about the data: disk or tapes. For example:

list,

  class     = od,
  type      = an,
  expver    = 1,
  stream    = kwbc,
  date      = 19990222,
  time      = 0000/1200,
  levtype   = pl,
  levelist  = 1000/850/500,
  param     = 129/130,
  output    = cost

Will generate:

size=88728;
number_of_fields=6;
online_size=0;
off_line_size=88728;
number_of_tape_files=1;
number_of_disk_files=0;
number_of_online_fields=0;
number_of_offline_fields=6;
number_of_tapes=1;

This information is useful to see if the data is scattered across too many tapes (maybe you have to rewrite the request). It also provides a foresight of the time the request could spend retrieving the data.