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DCMTK ENVIRONMENT VARIABLES
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The behaviour of the DCMTK tools and libraries can be modified by a
number of runtime environment variables which are explained below.
DCMDICTPATH
Affected: dcmdata
Explanation: On Unix platforms, all DCMTK applications load a DICOM
data dictionary from file upon startup. By default, the file
/usr/local/dicom/lib/dicom.dic will be loaded. If the DCMDICTPATH
environment variable is set, the applications will attempt to load
DICOM data dictionaries specified in the DCMDICTPATH environment
variable instead. The DCMDICTPATH environment variable has the same
format as the shell PATH variable in that a colon (":") separates
entries. The data dictionary code will attempt to load each file
specified in the DCMDICTPATH environment variable. It is an error
if no data dictionary can be loaded.
On Win32 platforms, a built-in dictionary is used by default. If
the DCMDICTPATH environment variable is set, the applications will
attempt to load _additional_ DICOM data dictionaries specified in
the DCMDICTPATH environment variable instead. The DCMDICTPATH
environment variable has the same format as the shell PATH variable
in that a semicolon (";") separates entries. The data dictionary
code will attempt to load each file specified in the DCMDICTPATH
environment variable.
See also: documentation in dcmdata/docs/datadict.txt
TCP_BUFFER_LENGTH
Affected: dcmnet
Explanation: By default, DCMTK uses a TCP send and receive buffer
length of 32K. If the environment variable TCP_BUFFER_LENGTH is set,
it specified an override for the TCP buffer length. The value is
specified in bytes, not in Kbytes.
TCP_NODELAY
Affected: dcmnet
Explanation: If this environment variable contains a non-zero number,
the Nagle algorithm will not be disabled for TCP transport
connections. Also see documentation for macro
DONT_DISABLE_NAGLE_ALGORITHM in config/docs/macros.txt
TMPDIR
Affected: dcmnet
Explanation: Affects the implementation of the tempnam() emulation on
platforms where tempnam() is not defined. See tempnam(3S) man page
for a description.