= Environment Options =

This page lists some features which are often only available via environment variables, or where the environment variables override other options.

This list evolves constantly and should not be used as a definitive reference, only the source code for a particular version is.

There are also many environment variables which can be set for debugging, see [/wiki/Logging].

Unless the environment value is specified as being a number or a list, the possible values are:
* 0 to disable
* 1 to enable
No other values should be used (undefined behaviour).
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{{{#!div class="box"
== Generic System Environment Variables

These variables may be defined by the system before xpra is launched.

||HOME ||User UUID ||
||XDG_CURRENT_DESKTOP ||Detect the Ubuntu 'Unity' desktop ||
||LD_LIBRARY_PATH ||Locate [/wiki/FakeXinerama] and other libraries ||
||DBUS_SESSION_BUS_ADDRESS ||Locate the dbus session server ||

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== Internal ==

||Variable ||Meaning || Default Value||
||DEFAULT_XPRA_CONF_FILENAME||Configuration file name || 'xpra.conf'||
||DEFAULT_NET_WM_NAME||To change the window manager name, aka {{{_NET_WM_NAME}}} (see ticket:705#comment:10) || 'Xpra'||
||NO_ROOT_WARNING ||Skip warning if running as root || 0||
||INITENV_COMMAND ||The command we run via ssh to ensure the environment is ready || "xpra initenv"||
||XPRA_USE_PROCESS_POLLING ||Use process polling instead of relying on SIGCHLD || 0||
||XPRA_SKIP_UI ||Skip warnings, useful when running without a console || 0||
||XPRA_FORCE_COLOR_LOG ||Force enable the coloured logger || 0||

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== Encodings ==

||XPRA_NVENC_VERSIONS ||Which versions of NVENC to try to load and in which order || 4,5||
||XPRA_IGNORE_NVIDIA_DRIVER_BLACKLIST ||Ignore the builtin driver version blacklist || 0||
||XPRA_NVENC_CLIENT_KEY ||Provide a client key for NVENC || ||
||XPRA_NVENC_PRESET ||Prefer a specific preset || ||
||XPRA_NVENC_YUV444_THRESHOLD ||Quality above which YUV444 mode is preferred || 85||
||XPRA_NVENC_LOSSLESS_THRESHOLD ||Quality above which lossless mode is used || 100||
||XPRA_NVENC_DEBUG_API ||Debug NVENC API calls || 0||
||XPRA_CUDA_DEVICE ||Cuda Device ID to use || -1 (first available)||
||XPRA_CUDA_DEVICE_NAME ||Cuda device name to use (ie: "GTX 970") || ||
||PIL_DEBUG ||Enable Python Pillow debugging || 0||
||XPRA_CODEC_SELFTEST ||Run self tests on start || 1||
||XPRA_CODEC_FULL_SELFTEST ||Run full self tests on start (expensive) || 0||
||XPRA_OPENCL_DEVICE_TYPE ||The type of device to use || GPU||
||XPRA_OPENCL_DEVICE_NAME ||Select a specific device by name || ||
||XPRA_OPENCL_PLATFORM ||Select a specific OpenCL platform || ||
||XPRA_OPENCL_YUV2RGB ||Support YUV to RGB via OpenCL|| 0||
||XPRA_AMD_WARNING ||Show warning if the AMD OpenCL ICD is loaded || 1||
||XPRA_CSC_CYTHON_$$$$$$$_COLORSPACES ||Restrict which format conversions are supported with the cython csc module (see ticket:937#comment:21) || ||
||XPRA_CSC_CYTHON_DEBUG_POINTS ||Debug colour for specific pixels with the csc cython module || ||
||XPRA_VP9_YUV444 ||Enable YUV444 mode with VP9 if available || 1||
||XPRA_VP9_TILING ||Enable VP9 tiling support || 0||
||XPRA_VPX_THREADS ||Number of threads to use with VP9|| number of CPUs-1||
||XPRA_FORCE_SWSCALE ||Enable swscale with blacklisted versions || 0||
||XPRA_X264_THREADS ||Number of threads to use with x264 || 0 (auto)||
||XPRA_X264_LOGGING ||x264 API logging level, supported values: ERROR,WARNING,INFO || WARNING||
||XPRA_X264_LOG_NALS ||Log x264 NALs || 0||
||XPRA_X264_OPENCL ||Use OpenCL if present || 0||
||XPRA_X264_$$$$$$_PROFILE ||Profile to use for a given csc mode || ||
||XPRA_WEBP_LOG_CONFIG ||Log webp config used || 0||
||XPRA_WEBP_THREADING ||Enable webp threading || 1||
||XPRA_WEBP_IMAGE_HINT ||Default webp image hint || graph||
||XPRA_WEBP_PRESET ||Default webp preset || text||
||XPRA_WEBP_PRESET_SMALL ||Default webp preset for small areas || icon||



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== X11 ==

||XPRA_X_SYNC ||Enable [https://tronche.com/gui/x/xlib/event-handling/protocol-errors/XSynchronize.html XSynchronize] || 0||
||XPRA_X11_PROPERTIES_IGNORED ||X11 properties we ignore as a CSV list || "_NET_WM_OPAQUE_REGION"||
||XPRA_FORCE_REPLACE_WM ||Force an existing window manager to exit || 0||
||XPRA_LOG_MANAGE_FAILURES ||Log all failures to manage a window || 0||
||XPRA_NO_NET_SUPPORTED||CSV list of "_NET_SUPPORTED" items to remove from the default list we claim to support || ||
||XPRA_X11_DEBUG_EVENTS ||CSV list of X11 events to debug - typical values: {{{KeyPress,ClientMessage}}} .. || ||
||XPRA_REPARENT_ROOT ||Reparent windows to the root window, see #770 || 0||
||XPRA_X11_XKB ||Enable Xkb || 1||
||XPRA_X11_XTEST ||Enable XTest || 1||
||XPRA_X11_XFIXES ||Enable XFixes || 1||
||XPRA_DEBUG_KEYSYMS ||Debug the key mapping for specific keys || ||
||XPRA_XSETTINGS_DEBUG ||Debug XSettings|| 0||


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== Network / Connection ==

||XPRA_SOCKET_HOSTNAME||The name to use for the sockets || the hostname||
||SOCKET_TIMEOUT||How long to wait before the initial connection times out || 10||
||TCP_NODELAY ||Use TCP no-delay || 1||
||XPRA_PASSWORD ||Override the password file option || ||
||XPRA_ENCRYPTION_KEY ||Override the encryption key file option || ||
||XPRA_XSHM ||Enable XShm|| 1||
||XPRA_WRAPPER_DEBUG ||Debug the process wrapper || 0||
||XPRA_HEXLIFY_PACKETS ||Dump the process wrapper's packets in hex form || 0||
||XPRA_WIN32_SHOWWINDOW ||Run the process wrapper in a shell window on MS Windows || 0||
||XPRA_USE_RENCODER ||Use rencode if available || 1||
||XPRA_USE_BENCODER ||Use bencode if available || 1||
||XPRA_USE_YAML ||Use yaml if available || 1||
||USE_CYTHON_BENCODE ||Use the Cython version of the bencoder || 1||
||XPRA_USE_ALIASES ||Use aliases for packet headers || 1||
||XPRA_READ_BUFFER_SIZE ||Size of the network packet read buffer || 65536||
||XPRA_PACKET_JOIN_SIZE ||Size below which packets and headers are joined up together || same as read buffer size||
||LARGE_PACKET_SIZE ||Size above which uncompressed data in packets triggers a warning || 4096||
||XPRA_INLINE_SIZE ||Size below which compressed data is sent inlined in the main packet || 32768||
||XPRA_MIN_COMPRESS_SIZE ||Size below which we don't try to compress the packet || 378||
||XPRA_ENABLE_CRYPTO ||Enable encryption layer || 1||
||XPRA_ENCRYPT_FIRST_PACKET ||Send the first packet encrypted (see #951) || 0||
||XPRA_CRYPTO_DEFAULT_IV ||Override the crypto iv || (default is random)||
||XPRA_CRYPTO_DEFAULT_SALT ||Override the crypto salt || (default is random)||
||XPRA_CRYPTO_DEFAULT_ITERATIONS ||Override number of iterations || 1000||
||XPRA_CRYPTO_INITIAL_PADDING ||Padding used in the initial packet (see #933) || legacy||
||XPRA_CRYPTO_PREFERRED_PADDING ||Padding used (if supported) || PKCS#7||


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== Fault Injection ==

For "rate" types of settings, the value is a number and specifies how often we simulate errors: a value of 10 will cause 1 error for every 10 events.

||XPRA_PAINT_FAULT_INJECTION_RATE ||Simulate errors in paint events || 0||
||XPRA_PAINT_FAULT_INJECTION_TELL ||Whether paint errors are reported back to the server || 1||
||XPRA_WRAPPER_FAULT_INJECTION_RATE ||Simulate communication errors in the process wrapper || 0||
||XPRA_PROTOCOL_FAULT_INJECTION_RATE ||Simulate network packet errors|| 0||
||XPRA_FAKE_JITTER ||Introduce jitter in the network layer (value in milliseconds)|| 0||


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== Clipboard ==

||XPRA_DISCARD_TARGETS ||List of clipboard targets which are discarded ||
||XPRA_TRANSLATEDCLIPBOARD_LOCAL_SELECTION ||Default local selection for translated clipboard ||
||XPRA_TRANSLATEDCLIPBOARD_REMOTE_SELECTION ||Default remote selection for translated clipboard ||
}}}