|
DCMTK Version 3.6.9
OFFIS DICOM Toolkit
|
===========================
DCMTK ENVIRONMENT VARIABLES
===========================
The behavior 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/share/
dcmtk-<VERSION>/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 or
/usr/local/share/doc/dcmtk-<VERSION>/datadict.txt.
DCMICONVPATH
Affected: oficonv
Explanation: The oficonv library uses a set of data files containing encoding
scheme database and character set mapping data. By default, the files are
expected in the "esdb" and "csmapper" subdirectories of the
DEFAULT_SUPPORT_DATA_DIR directory. This environment variable can be used
to specify a different data directory containing the "esdb" and "csmapper"
subdirectories.
TCP_BUFFER_LENGTH
Affected: dcmnet
Explanation: By default, DCMTK does not modify the TCP send and receive buffer
length, i.e. the operating system is responsible for selecting appropriate
values. If the environment variable TCP_BUFFER_LENGTH is set, it specifies
an override for the TCP buffer length. The value is specified in bytes, not
in Kbytes. If set to 0, a buffer length of 64K, which was the default value
for previous versions of the DCMTK, is used.
TCP_NODELAY
Affected: dcmnet
Explanation: If this environment variable is set and contains a non-zero
number (e.g. "1"), the Nagle algorithm will be disabled for TCP transport
connections, which might result in better network performance on some
systems/environments, especially when many small network packets are to
be sent. If it is set and contains the number "0", the Nagle algorithm
will not be disabled. If the environment variable TCP_NODELAY is not set,
the default behavior applies (see compiler macro DISABLE_NAGLE_ALGORITHM
in config/docs/macros.txt or /usr/local/share/doc/dcmtk-<VERSION>/
macros.txt).