FXMAKEMAP Name
FXMAKEMAP
Author
Craig B. Markwardt, NASA/GSFC Code 662, Greenbelt, MD 20770
craigm@lheamail.gsfc.nasa.gov
UPDATED VERSIONs can be found on my WEB PAGE:
http://cow.physics.wisc.edu/~craigm/idl/idl.html
Purpose
Change configuration of FXG - FXFILTER'ed behavior
Major Topics
File I/O, Pipes, URLs, FITS Calling Sequence
FXMAKEMAP, SUFFIX, COMMAND or
FXMAKEMAP, /INFO or
FXMAKEMAP, [SCRATCH_DIR=scratch,] [BUFFER_MAX=bufmax,]
[BUFFER_GRAN=bufgran,] [RM_COMMAND=rmcommand,] [/GET]
Description
FXMAKEMAP queries or sets the behavior of the FXFILTER family of
functions (FXGOPEN, FXGREAD, FXGWRITE, FXGSEEK, and FXGCLOSE).
To add a new file extension mapping, which associates a filename
suffix with a particular Unix pipe command, use the first form of
the command.
To print the current settings, including the file extension maps,
use the /INFO form of the command.
To set an individual parameter, call FXMAKEMAP with the
appropriate keyword argument.
To query an individual parameter, call FXMAKEMAP with /GET and the
appropriate keyword argument.
Inputs
SUFFIX - the trailing suffix of the filename to be associated,
*without* the period. For example, for a gzipped file,
the suffix is 'gz'
COMMAND - an IDL-style format command which specifies how the
filename should be converted into a Unix pipe command.
The actual command is constructed by passing the
filename to STRING() with this format string. For
example, to convert a gzip file the proper format string
is, '("gzip -dc ",A0)'.
Keyword Parameters
INFO - print the current settings and return.
GET - if this keyword is set, then the following keyword commands
cause the current setting to be returned in the specified
keyword. Otherwise the default is to assert a new setting.
BUFFER_GRAN - the buffer granularity in bytes. I/O operations on
pipes and streams are performed in multiples of this
size. Default: 4096 bytes.
BUFFER_MAX - the maximum allowed buffer size in bytes. I/O
operations on pipes and streams are performed with at
most this many bytes. Default: 32 kbytes.
RM_COMMAND - the Unix command used to delete files.
Default: '/bin/rm'
SCRATCH_DIR - the scratch directory where cache files are stored.
When operations on Unix pipes or streams are
performed, the data are stored in individual files
in this directory.
Modification History
Written, 1999, CM
Documented, 02 Oct 1999, CM
Changed copyright notice, 21 Sep 2000, CM
2012-04-17 Promote file position pointers to LONG64, CM