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The following list summarises the environment variables used by the
NDF library to control access to foreign format data. The symbols
<FMT> and <XTN> are used to represent the names of foreign
data formats and NDF extensions respectively. All environment
variable names should be entirely in upper case.
- NDF_FORMATS_IN
-
Comma-separated list of format names and associated file extensions,
used when accessing pre-existing datasets. (Mandatory if pre-existing
foreign datasets are to be accessed.)
- NDF_FORMATS_OUT
-
Comma-separated list of format names and associated file extensions,
used when accessing new datasets. (Mandatory if new foreign datasets
are to be accessed other than by propagation of format information
from a pre-existing dataset.)
- NDF_FROM_<FMT>
-
Command to convert a foreign format dataset into an NDF. (Mandatory if
datasets in that format are to be read.)
- NDF_TO_<FMT>
-
Command to convert an NDF into a foreign format dataset. (Mandatory if
datasets in that format are to be written or modified.)
- NDF_DEL_<FMT>
-
Command to delete a foreign format dataset. (Optional.)
- NDF_KEEP_<FMT>
-
Name of the NDF to be used to hold a native format copy of a foreign
dataset in cases where the NDF is to be retained for future
use. (Optional.)
- NDF_TEMP_<FMT>
-
Name of the NDF to be used to hold a native format copy of a foreign
dataset in cases where the NDF is temporary and will be deleted when
the dataset is released. (Optional.)
- NDF_XTN
-
Comma-separated list of NDF extensions to be recognised when accessing
foreign datasets. (Optionally required if extension information is to
be handled.)
- NDF_XTN_<XTN>
-
Comma-separated list of NDF extensions to be recognised when accessing
datasets in a particular foreign format. (Optionally overrides the
value of NDF_XTN for that format.)
- NDF_IMP_<XTN>
-
Command to import information into an NDF extension. (Optionally
required to allow reading of extension information from foreign
datasets.)
- NDF_IMP_<XTN>_<FMT>
-
Command to import information into an NDF extension when accessing
datasets in a particular foreign format. (Optionally overrides the
value of NDF_IMP_<XTN> for that format.)
- NDF_EXP_<XTN>
-
Command to export information from an NDF extension. (Optionally
required to allow writing or modification of extension information in
foreign datasets.)
- NDF_EXP_<XTN>_<FMT>
-
Command to export information from an NDF extension when accessing
datasets in a particular foreign format. (Optionally overrides the
value of NDF_EXP_<XTN> for that format.)
Next: Summary of Message Tokens Used
Up: ENVIRONMENT VARIABLES AND TOKENS
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Starlink System Note 20
R.F.Warren-Smith & D.S.Berry
17th July 2000
E-mail:ussc@star.rl.ac.uk
Copyright © 2000 Council for the Central Laboratory of the Research Councils