neulab/tldr huggingface dataset:
--assembly-loader=MODE If mode is strict, Mono will check that the public key token, culture and version of a candidate assembly matches the requested strong name.  If mode is legacy, as long as the name matches, the candidate will be allowed. strict is the behavior consistent with .NET Framework but may break some existing mono-based applications.  The default is legacy.
--attach=[options] Currently the only option supported by this command line argument is disable which disables the attach functionality.
--config filename Load the specified configuration file instead of the default one(s).  The default files are /etc/mono/config and ~/.mono/config or the file specified in the MONO_CONFIG environment variable, if set.  See the mono-config(5) man page for details on the format of this file.
--debugger-agent=[options] This instructs the Mono runtime to start a debugging agent inside the Mono runtime and connect it to a client user interface will control the Mono process.  This option is typically used by IDEs, like the MonoDevelop or Visual Studio IDEs. The configuration is specified using one of more of the following options:
address=host:port Use this option to specify the IP address where your debugger client is listening to.
loglevel=LEVEL Specifies the diagnostics log level for
logfile=filename Used to specify the file where the log will be stored, it defaults to standard output.
server=[y/n] Defaults to no, with the default option Mono will actively connect to the host/port configured with the address option.  If you set it to 'y', it instructs the Mono runtime to start debugging in server mode, where Mono actively waits for the debugger front end to connect to the Mono process. Mono will print out to stdout the IP address and port where it is listening.
setpgid=[y/n] If set to yes, Mono will call setpgid(0, 0) on startup, if that function is available on the system. This is useful for ensuring that signals delivered to a process that is executing the debuggee are not propagated to the debuggee, e.g. when Ctrl-C sends SIGINT to the sdb tool.
suspend=[y/n] Defaults to yes, with the default option Mono will suspend the vm on startup until it connects successfully to a debugger front end.  If you set it to 'n', in conjunction with server=y, it instructs the Mono runtime to run as normal, while caching metadata to send to the debugger front end on connection..
transport=transport_name This is used to specify the transport that the debugger will use to communicate.   It must be specified and currently requires this to be 'dt_socket'.
--desktop Configures the virtual machine to be better suited for desktop applications.  Currently this sets the GC system to avoid expanding the heap as much as possible at the expense of slowing down garbage collection a bit.
--full-aot This flag instructs the Mono runtime to not generate any code at runtime and depend exclusively on the code generated from using mono --aot=full previously.  This is useful for platforms that do not permit dynamic code generation, or if you need to run assemblies that have been stripped of IL (for example using mono-cil-strip).  Notice that this feature will abort execution at runtime if a codepath in your program, or Mono's class libraries attempts to generate code dynamically.  You should test your software upfront and make sure that you do not use any dynamic features.
--full-aot-interp Same as --full-aot with fallback to the interpreter.
--gc=boehm, --gc=sgen Selects the Garbage Collector engine for Mono to use, Boehm or SGen.  Currently this merely ensures that you are running either the mono or mono-sgen commands.    This flag can be set in the MONO_ENV_OPTIONS environment variable to force all of your child processes to use one particular kind of GC with the Mono runtime.
--gc-debug=[options] Command line equivalent of the MONO_GC_DEBUG environment variable.
--gc-params=[options] Command line equivalent of the MONO_GC_PARAMS environment variable.
--arch=32, --arch=64 (Mac OS X only): Selects the bitness of the Mono binary used, if available. If the binary used is already for the selected bitness, nothing changes. If not, the execution switches to a binary with the selected bitness suffix installed side by side (for example, '/bin/mono --arch=64' will switch to '/bin/mono64' iff '/bin/mono' is a 32-bit build).
--help, -h Displays usage instructions.
--interpreter The Mono runtime will use its interpreter to execute a given assembly.  The interpreter is usually slower than the JIT, but it can be useful on platforms where code generation at runtime is not allowed.
--hybrid-aot This flag allows the Mono runtime to run assemblies that have been stripped of IL, for example using mono-cil-strip. For this to work, the assembly must have been AOT compiled with --aot=hybrid.
This flag is similar to --full-aot, but it does not disable the JIT. This means you can use dynamic features such as System.Reflection.Emit.
--llvm If the Mono runtime has been compiled with LLVM support (not available in all configurations), Mono will use the LLVM optimization and code generation engine to JIT or AOT compile.  For more information, consult: http://www.mono- project.com/docs/advanced/mono-llvm/
--ffast-math This flag allows Mono and LLVM to apply aggressive floating point optimizations.  Can break IEEE754 compliance.
--nollvm When using a Mono that has been compiled with LLVM support, it forces Mono to fallback to its JIT engine and not use the LLVM backend.
--optimize=MODE, -O=MODE MODE is a comma separated list of optimizations.  They also allow optimizations to be turned off by prefixing the optimization name with a minus sign.  In general, Mono has been tuned to use the default set of flags, before using these flags for a deployment setting, you might want to actually measure the benefits of using them.  The following optimization flags are implemented in the core engine: abcrem     Array bound checks removal all        Turn on all optimizations aot        Usage of Ahead Of Time compiled code branch     Branch optimizations cfold      Constant folding cmov       Conditional moves [arch-dependency] deadce     Dead code elimination consprop   Constant propagation copyprop   Copy propagation fcmov      Fast x86 FP compares [arch-dependency] float32     Perform 32-bit float arithmetic using 32-bit operations gshared    Enable generic code sharing. inline     Inline method calls intrins    Intrinsic method implementations linears    Linear scan global reg allocation leaf       Leaf procedures optimizations loop       Loop related optimizations peephole   Peephole postpass precomp    Precompile all methods before executing Main sched      Instruction scheduling shared     Emit per-domain code sse2       SSE2 instructions on x86 [arch-dependency] tailc      Tail recursion and tail calls For example, to enable all the optimization but dead code elimination and inlining, you can use: -O=all,-deadce,-inline The flags that are flagged with [arch-dependency] indicate that the given option if used in combination with Ahead of Time compilation (--aot flag) would produce pre-compiled code that will depend on the current CPU and might not be safely moved to another computer.
The following optimizations are supported
float32 Requests that the runtime performn 32-bit floating point operations using only 32-bits.   By default the Mono runtime tries to use the highest precision available for floating point operations, but while this might render better results, the code might run slower.   This options also affects the code generated by the LLVM backend.
inline Controls whether the runtime should attempt to inline (the default), or not inline methods invocations --response=FILE Provides a response file, this instructs the Mono command to read other command line options from the specified file, as if the options had been specified on the command line. Useful when you have very long command lines.
--runtime=VERSION Mono supports different runtime versions. The version used depends on the program that is being run or on its configuration file (named program.exe.config). This option can be used to override such autodetection, by forcing a different runtime version to be used. Note that this should only be used to select a later compatible runtime version than the one the program was compiled against. A typical usage is for running a 1.1 program on a 2.0 version: mono --runtime=v2.0.50727 program.exe
--server Configures the virtual machine to be better suited for server operations (currently, allows a heavier threadpool initialization).
--use-map-jit Instructs Mono to generate code using MAP_JIT on MacOS. Necessary for bundled applications.
--verify-all Verifies mscorlib and assemblies in the global assembly cache for valid IL, and all user code for IL verifiability.
This is different from --security's verifiable or validil in that these options only check user code and skip mscorlib and assemblies located on the global assembly cache.
-V, --version Prints JIT version information (system configuration, release number and branch names if available).
--version=number Print version number only.
The following options are used to help when developing a JITed application.
--debug, --debug=OPTIONS Turns on the debugging mode in the runtime.  If an assembly was compiled with debugging information, it will produce line number information for stack traces.
The optional OPTIONS argument is a comma separated list of debugging options.  These options are turned off by default since they generate much larger and slower code at runtime.
casts  Produces a detailed error when throwing a InvalidCastException.   This option needs to be enabled as this generates more verbose code at execution time.
mdb-optimizations Disable some JIT optimizations which are usually only disabled when running inside the debugger.  This can be helpful if you want to attach to the running process with mdb.
gdb    Generate and register debugging information with gdb. This is only supported on some platforms, and only when using gdb 7.0 or later.
--profile[=profiler[:profiler_args]] Loads a profiler module with the given arguments. For more information, see the PROFILING section.  This option can be used multiple times; each time will load an additional profiler module.
--trace[=expression] Shows method names as they are invoked.  By default all methods are traced.  The trace can be customized to include or exclude methods, classes or assemblies.  A trace expression is a comma separated list of targets, each target can be prefixed with a minus sign to turn off a particular target.  The words `program', `all' and `disabled' have special meaning.  `program' refers to the main program being executed, and `all' means all the method calls.  The `disabled' option is used to start up with tracing disabled.  It can be enabled at a later point in time in the program by sending the SIGUSR2 signal to the runtime.  Assemblies are specified by their name, for example, to trace all calls in the System assembly, use:
mono --trace=System app.exe
Classes are specified with the T: prefix.  For example, to trace all calls to the System.String class, use:
mono --trace=T:System.String app.exe
And individual methods are referenced with the M: prefix, and the standard method notation:
mono --trace=M:System.Console:WriteLine app.exe
Exceptions can also be traced, it will cause a stack trace to be printed every time an exception of the specified type is thrown. The exception type can be specified with or without the namespace, and to trace all exceptions, specify 'all' as the type name.
mono --trace=E:System.Exception app.exe
As previously noted, various rules can be specified at once:
mono --trace=T:System.String,T:System.Random app.exe
You can exclude pieces, the next example traces calls to System.String except for the System.String:Concat method.
mono --trace=T:System.String,-M:System.String:Concat
You can trace managed to unmanaged transitions using the wrapper qualifier:
mono --trace=wrapper app.exe
Finally, namespaces can be specified using the N: prefix:
mono --trace=N:System.Xml
--no-x86-stack-align Don't align stack frames on the x86 architecture.  By default, Mono aligns stack frames to 16 bytes on x86, so that local floating point and SIMD variables can be properly aligned.  This option turns off the alignment, which usually saves one instruction per call, but might result in significantly lower floating point and SIMD performance.
--jitmap Generate a JIT method map in a /tmp/perf-PID.map file. This file is then used, for example, by the perf tool included in recent Linux kernels.  Each line in the file has:
HEXADDR HEXSIZE methodname
Currently this option is only supported on Linux.
The maintainer options are only used by those developing the runtime itself, and not typically of interest to runtime users or developers.
--bisect=optimization:filename This flag is used by the automatic optimization bug bisector.  It takes an optimization flag and a filename of a file containing a list of full method names, one per line.  When it compiles one of the methods in the file it will use the optimization given, in addition to the optimizations that are otherwise enabled.  Note that if the optimization is enabled by default, you should disable it with `-O`, otherwise it will just apply to every method, whether it's in the file or not.
--break method Inserts a breakpoint before the method whose name is `method' (namespace.class:methodname).  Use `Main' as method name to insert a breakpoint on the application's main method.  You can use it also with generics, for example "System.Collections.Generic.Queue`1:Peek"
--breakonex Inserts a breakpoint on exceptions.  This allows you to debug your application with a native debugger when an exception is thrown.
--compile name This compiles a method (namespace.name:methodname), this is used for testing the compiler performance or to examine the output of the code generator.
--compile-all Compiles all the methods in an assembly.  This is used to test the compiler performance or to examine the output of the code generator
--graph=TYPE METHOD This generates a postscript file with a graph with the details about the specified method (namespace.name:methodname).  This requires `dot' and ghostview to be installed (it expects Ghostview to be called "gv").  The following graphs are available: cfg        Control Flow Graph (CFG) dtree      Dominator Tree code       CFG showing code ssa        CFG showing code after SSA translation optcode    CFG showing code after IR optimizations Some graphs will only be available if certain optimizations are turned on.
--ncompile Instruct the runtime on the number of times that the method specified by --compile (or all the methods if --compile-all is used) to be compiled.  This is used for testing the code generator performance.
--stats=[method] Displays information about the work done by the runtime during the execution of an application. If a method (namespace.name:methodname) is specified, it will display that information when the method is first run in addition to the end of program execution.
--wapi=hps|semdel Perform maintenance of the process shared data.  semdel will delete the global semaphore.  hps will list the currently used handles.
-v, --verbose Increases the verbosity level, each time it is listed, increases the verbosity level to include more information (including, for example, a disassembly of the native code produced, code selector info etc.).
The Mono runtime allows external processes to attach to a running process and load assemblies into the running program.   To attach to the process, a special protocol is implemented in the Mono.Management assembly.
With this support it is possible to load assemblies that have an entry point (they are created with -target:exe or -target:winexe) to be loaded and executed in the Mono process.
The code is loaded into the root domain, and it starts execution on the special runtime attach thread.    The attached program should create its own threads and return after invocation.
This support allows for example debugging applications by having the csharp shell attach to running processes.
The Mono runtime includes a profiler API that dynamically loaded profiler modules and embedders can use to collect performance-related data about an application. Profiler modules are loaded by passing the --profile command line argument to the Mono runtime.
Mono ships with a few profiler modules, of which the log profiler is the most feature-rich. It is also the default profiler if the profiler argument is not given, or if default is given.  It is possible to write your own profiler modules; see the Custom profilers sub-section.
Log profiler The log profiler can be used to collect a lot of information about a program running in the Mono runtime. This data can be used (both while the process is running and later) to do analyses of the program behavior, determine resource usage, performance issues or even look for particular execution patterns.
This is accomplished by logging the events provided by the Mono runtime through the profiler API and periodically writing them to a file which can later be inspected with the mprof-report(1) tool.
More information about how to use the log profiler is available on the mono-profilers(1) page, under the LOG PROFILER section, as well as the mprof-report(1) page.
Coverage profiler The code coverage profiler can instrument a program to help determine which classes, methods, code paths, etc are actually executed. This is most useful when running a test suite to determine whether the tests actually cover the code they're expected to.
More information about how to use the coverage profiler is available on the mono-profilers(1) page, under the COVERAGE PROFILER section.
AOT profiler The AOT profiler can help improve startup performance by logging which generic instantiations are used by a program, which the AOT compiler can then use to compile those instantiations ahead of time so that they won't have to be JIT compiled at startup.
More information about how to use the AOT profiler is available on the mono-profilers(1) page, under the AOT PROFILER section.
Custom profilers Custom profiler modules can be loaded in exactly the same way as the standard modules that ship with Mono. They can also access the same profiler API to gather all kinds of information about the code being executed.
For example, to use a third-party profiler called custom, you would load it like this:
mono --profile=custom program.exe
You could also pass arguments to it:
mono --profile=custom:arg1,arg2=arg3 program.exe
In the above example, Mono will load the profiler from the shared library called libmono-profiler-custom.so (name varies based on platform, e.g., libmono-profiler-custom.dylib on OS X).  This profiler module must be on your dynamic linker library path (LD_LIBRARY_PATH on most systems, DYLD_LIBRARY_PATH on OS X).
For a sample of how to write your own custom profiler, look at the samples/profiler/sample.c file in the Mono source tree.
To debug managed applications, you can use the mdb command, a command line debugger.
It is possible to obtain a stack trace of all the active threads in Mono by sending the QUIT signal to Mono, you can do this from the command line, like this:
kill -QUIT pid
Where pid is the Process ID of the Mono process you want to examine.  The process will continue running afterwards, but its state is not guaranteed.
Important: this is a last-resort mechanism for debugging applications and should not be used to monitor or probe a production application.  The integrity of the runtime after sending this signal is not guaranteed and the application might crash or terminate at any given point afterwards.
The --debug=casts option can be used to get more detailed information for Invalid Cast operations, it will provide information about the types involved.
You can use the MONO_LOG_LEVEL and MONO_LOG_MASK environment variables to get verbose debugging output about the execution of your application within Mono.
The MONO_LOG_LEVEL environment variable if set, the logging level is changed to the set value. Possible values are "error", "critical", "warning", "message", "info", "debug". The default value is "error". Messages with a logging level greater then or equal to the log level will be printed to stdout/stderr.
Use "info" to track the dynamic loading of assemblies.
Use the MONO_LOG_MASK environment variable to limit the extent of the messages you get: If set, the log mask is changed to the set value. Possible values are "asm" (assembly loader), "type", "dll" (native library loader), "gc" (garbage collector), "cfg" (config file loader), "aot" (precompiler), "security" (e.g. Moonlight CoreCLR support), "threadpool" (thread pool generic), "io-selector" (async socket operations), "io-layer" (I/O layer - processes, files, sockets, events, semaphores, mutexes and handles), "io-layer-process", "io-layer-file", "io-layer-socket", "io-layer-event", "io-layer-semaphore", "io-layer- mutex", "io-layer-handle" and "all".  The default value is "all". Changing the mask value allows you to display only messages for a certain component. You can use multiple masks by comma separating them. For example to see config file messages and assembly loader messages set you mask to "asm,cfg".
The following is a common use to track down problems with P/Invoke:
$ MONO_LOG_LEVEL="debug" MONO_LOG_MASK="dll" mono glue.exe
If you are using LLDB, you can use the mono.py script to print some internal data structures with it.   To use this, add this to your $HOME/.lldbinit file: command script import $PREFIX/lib/mono/lldb/mono.py
Where $PREFIX is the prefix value that you used when you configured Mono (typically /usr).
Once this is done, then you can inspect some Mono Runtime data structures, for example: (lldb) p method
(MonoMethod *) $0 = 0x05026ac0 [mscorlib]System.OutOfMemoryException:.ctor()
Mono's XML serialization engine by default will use a reflection-based approach to serialize which might be slow for continuous processing (web service applications).  The serialization engine will determine when a class must use a hand-tuned serializer based on a few parameters and if needed it will produce a customized C# serializer for your types at runtime.  This customized serializer then gets dynamically loaded into your application.
You can control this with the MONO_XMLSERIALIZER_THS environment variable.
The possible values are `no' to disable the use of a C# customized serializer, or an integer that is the minimum number of uses before the runtime will produce a custom serializer (0 will produce a custom serializer on the first access, 50 will produce a serializer on the 50th use). Mono will fallback to an interpreted serializer if the serializer generation somehow fails. This behavior can be disabled by setting the option `nofallback' (for example: MONO_XMLSERIALIZER_THS=0,nofallback).
GC_DONT_GC Turns off the garbage collection in Mono.  This should be only used for debugging purposes
HTTP_PROXY (Also http_proxy) If set, web requests using the Mono Class Library will be automatically proxied through the given URL.  Not supported on Windows, Mac OS, iOS or Android. See also NO_PROXY.
LLVM_COUNT When Mono is compiled with LLVM support, this instructs the runtime to stop using LLVM after the specified number of methods are JITed.  This is a tool used in diagnostics to help isolate problems in the code generation backend.   For example LLVM_COUNT=10 would only compile 10 methods with LLVM and then switch to the Mono JIT engine.  LLVM_COUNT=0 would disable the LLVM engine altogether.
MONO_ASPNET_INHIBIT_SETTINGSMAP Mono contains a feature which allows modifying settings in the .config files shipped with Mono by using config section mappers. The mappers and the mapping rules are defined in the $prefix/etc/mono/2.0/settings.map file and, optionally, in the settings.map file found in the top-level directory of your ASP.NET application.  Both files are read by System.Web on application startup, if they are found at the above locations. If you don't want the mapping to be performed you can set this variable in your environment before starting the application and no action will be taken.
MONO_ASPNET_WEBCONFIG_CACHESIZE Mono has a cache of ConfigSection objects for speeding up WebConfigurationManager queries. Its default size is 100 items, and when more items are needed, cache evictions start happening. If evictions are too frequent this could impose unnecessary overhead, which could be avoided by using this environment variable to set up a higher cache size (or to lower memory requirements by decreasing it).
MONO_CAIRO_DEBUG_DISPOSE If set, causes Mono.Cairo to collect stack traces when objects are allocated, so that the finalization/Dispose warnings include information about the instance's origin.
MONO_CFG_DIR If set, this variable overrides the default system configuration directory ($PREFIX/etc). It's used to locate machine.config file.
MONO_COM Sets the style of COM interop.  If the value of this variable is "MS" Mono will use string marhsalling routines from the liboleaut32 for the BSTR type library, any other values will use the mono-builtin BSTR string marshalling.
MONO_CONFIG If set, this variable overrides the default runtime configuration file ($PREFIX/etc/mono/config). The --config command line options overrides the environment variable.
MONO_CPU_ARCH Override the automatic cpu detection mechanism. Currently used only on arm.  The format of the value is as follows:
"armvV [thumb[2]]"
where V is the architecture number 4, 5, 6, 7 and the options can be currently be "thumb" or "thumb2". Example:
MONO_CPU_ARCH="armv4 thumb" mono ...
MONO_ARM_FORCE_SOFT_FLOAT When Mono is built with a soft float fallback on ARM and this variable is set to "1", Mono will always emit soft float code, even if a VFP unit is detected.
MONO_DARWIN_USE_KQUEUE_FSW Fall back on the kqueue FileSystemWatcher implementation in Darwin. The default is the FSEvent implementation.
MONO_DARWIN_WATCHER_MAXFDS This is a debugging aid used to force limits on the kqueue FileSystemWatcher implementation in Darwin.   There is no limit by default.
MONO_DISABLE_MANAGED_COLLATION If this environment variable is `yes', the runtime uses unmanaged collation (which actually means no culture-sensitive collation). It internally disables managed collation functionality invoked via the members of System.Globalization.CompareInfo class. Collation is enabled by default.
MONO_DISABLE_SHARED_AREA Unix only: If set, disable usage of shared memory for exposing performance counters. This means it will not be possible to both externally read performance counters from this processes or read those of external processes.
MONO_DNS When set, enables the use of a fully managed DNS resolver instead of the regular libc functions. This resolver performs much better when multiple queries are run in parallel.
Note that /etc/nsswitch.conf will be ignored.
MONO_EGD_SOCKET For platforms that do not otherwise have a way of obtaining random bytes this can be set to the name of a file system socket on which an egd or prngd daemon is listening.
MONO_ENABLE_AIO If set, tells mono to attempt using native asynchronous I/O services. If not set, a default select/poll implementation is used. Currently epoll and kqueue are supported.
MONO_THREADS_SUSPEND Selects a mechanism that Mono will use to suspend threads.  May be set to "preemptive", "coop", or "hybrid". Threads may need to be suspended by the debugger, or using some .NET threading APIs, and most commonly when the SGen garbage collector needs to stop all threads during a critical phase of garbage collection.  Preemptive mode is the mode that Mono has used historically, going back to the Boehm days, where the garbage collector would run at any point and suspend execution of all threads as required to perform a garbage collection.  The cooperative mode on the other hand requires the cooperation of all threads to stop at a safe point.  This makes for an easier to debug garbage collector and it improves the stability of the runtime because threads are not suspended when accessing critical resources.  In scenarios where Mono is embedded in another application, cooperative suspend requires the embedder code to follow coding guidelines in order to cooperate with the garbage collector.  Cooperative suspend in embedded Mono is currently experimental.  Hybrid mode is a combination of the two that retains better compatability with scenarios where Mono is embedded in another application: threads that are running managed code or code that comprises the Mono runtime will be cooperatively suspended, while threads running embedder code will be preemptively suspended.  Hybrid suspend is the default on some desktop platforms.
Alternatively, coop and hybrid mode can be enabled at compile time by using the --enable-cooperative-suspend or --enable-hybrid- suspend flags, respectively, when calling configure.  The MONO_THREADS_SUSPEND environment variable takes priority over the compiled default.
MONO_ENABLE_COOP_SUSPEND This environment variable is obsolete, but retained for backward compatibility.  Use MONO_THREADS_SUSPEND set to "coop" instead. Note that if configure flags were provided to enable cooperative or hybrid suspend, this variable is ignored.
MONO_ENV_OPTIONS This environment variable allows you to pass command line arguments to a Mono process through the environment.   This is useful for example to force all of your Mono processes to use LLVM or SGEN without having to modify any launch scripts.
MONO_SDB_ENV_OPTIONS Used to pass extra options to the debugger agent in the runtime, as they were passed using --debugger-agent=.
MONO_EVENTLOG_TYPE Sets the type of event log provider to use (for System.Diagnostics.EventLog).  Possible values are:
local[:path] Persists event logs and entries to the local file system. The directory in which to persist the event logs, event sources and entries can be specified as part of the value. If the path is not explicitly set, it defaults to "/var/lib/mono/eventlog" on unix and "%APPDATA%no\ventlog" on Windows.
win32  Uses the native win32 API to write events and registers event logs and event sources in the registry.   This is only available on Windows.  On Unix, the directory permission for individual event log and event source directories is set to 777 (with +t bit) allowing everyone to read and write event log entries while only allowing entries to be deleted by the user(s) that created them.
null   Silently discards any events.
The default is "null" on Unix (and versions of Windows before NT), and "win32" on Windows NT (and higher).
MONO_EXTERNAL_ENCODINGS If set, contains a colon-separated list of text encodings to try when turning externally-generated text (e.g. command-line arguments or filenames) into Unicode.  The encoding names come from the list provided by iconv, and the special case "default_locale" which refers to the current locale's default encoding.
When reading externally-generated text strings UTF-8 is tried first, and then this list is tried in order with the first successful conversion ending the search.  When writing external text (e.g. new filenames or arguments to new processes) the first item in this list is used, or UTF-8 if the environment variable is not set.
The problem with using MONO_EXTERNAL_ENCODINGS to process your files is that it results in a problem: although its possible to get the right file name it is not necessarily possible to open the file.  In general if you have problems with encodings in your filenames you should use the "convmv" program.
MONO_GC_PARAMS When using Mono with the SGen garbage collector this variable controls several parameters of the collector.  The variable's value is a comma separated list of words.
max-heap-size=size Sets the maximum size of the heap. The size is specified in bytes and must be a power of two. The suffixes `k', `m' and `g' can be used to specify kilo-, mega- and gigabytes, respectively. The limit is the sum of the nursery, major heap and large object heap. Once the limit is reached the application will receive OutOfMemoryExceptions when trying to allocate.  Not the full extent of memory set in max- heap-size could be available to satisfy a single allocation due to internal fragmentation. By default heap limits is disabled and the GC will try to use all available memory.
nursery-size=size Sets the size of the nursery.  The size is specified in bytes and must be a power of two.  The suffixes `k', `m' and `g' can be used to specify kilo-, mega- and gigabytes, respectively.  The nursery is the first generation (of two).  A larger nursery will usually speed up the program but will obviously use more memory.  The default nursery size 4 MB.
major=collector Specifies which major collector to use.  Options are `marksweep' for the Mark&Sweep collector, `marksweep-conc' for concurrent Mark&Sweep and `marksweep-conc-par' for parallel and concurrent Mark&Sweep.  The concurrent Mark&Sweep collector is the default.
mode=balanced|throughput|pause[:max-pause] Specifies what should be the garbage collector's target. The `throughput' mode aims to reduce time spent in the garbage collector and improve application speed, the `pause' mode aims to keep pause times to a minimum and it receives the argument max-pause which specifies the maximum pause time in milliseconds that is acceptable and the `balanced' mode which is a general purpose optimal mode.
soft-heap-limit=size Once the heap size gets larger than this size, ignore what the default major collection trigger metric says and only allow four nursery size's of major heap growth between major collections.
evacuation-threshold=threshold Sets the evacuation threshold in percent.  This option is only available on the Mark&Sweep major collectors.  The value must be an integer in the range 0 to 100.  The default is 66.  If the sweep phase of the collection finds that the occupancy of a specific heap block type is less than this percentage, it will do a copying collection for that block type in the next major collection, thereby restoring occupancy to close to 100 percent.  A value of 0 turns evacuation off.
(no-)lazy-sweep Enables or disables lazy sweep for the Mark&Sweep collector.  If enabled, the sweeping of individual major heap blocks is done piecemeal whenever the need arises, typically during nursery collections.  Lazy sweeping is enabled by default.
(no-)concurrent-sweep Enables or disables concurrent sweep for the Mark&Sweep collector.  If enabled, the iteration of all major blocks to determine which ones can be freed and which ones have to be kept and swept, is done concurrently with the running program.  Concurrent sweeping is enabled by default.
stack-mark=mark-mode Specifies how application threads should be scanned. Options are `precise` and `conservative`. Precise marking allow the collector to know what values on stack are references and what are not.  Conservative marking threats all values as potentially references and leave them untouched. Precise marking reduces floating garbage and can speed up nursery collection and allocation rate, it has the downside of requiring a significant extra memory per compiled method. The right option, unfortunately, requires experimentation.
save-target-ratio=ratio Specifies the target save ratio for the major collector. The collector lets a given amount of memory to be promoted from the nursery due to minor collections before it triggers a major collection. This amount is based on how much memory it expects to free. It is represented as a ratio of the size of the heap after a major collection. Valid values are between 0.1 and 2.0. The default is 0.5. Smaller values will keep the major heap size smaller but will trigger more major collections. Likewise, bigger values will use more memory and result in less frequent major collections.  This option is EXPERIMENTAL, so it might disappear in later versions of mono.
default-allowance-ratio=ratio Specifies the default allocation allowance when the calculated size is too small. The allocation allowance is how much memory the collector let be promoted before triggered a major collection.  It is a ratio of the nursery size.  Valid values are between 1.0 and 10.0. The default is 4.0.  Smaller values lead to smaller heaps and more frequent major collections.  Likewise, bigger values will allow the heap to grow faster but use more memory when it reaches a stable size.  This option is EXPERIMENTAL, so it might disappear in later versions of mono.
minor=minor-collector Specifies which minor collector to use. Options are `simple' which promotes all objects from the nursery directly to the old generation, `simple-par' which has same promotion behavior as `simple' but using multiple workers and `split' which lets objects stay longer on the nursery before promoting.
alloc-ratio=ratio Specifies the ratio of memory from the nursery to be use by the alloc space.  This only can only be used with the split minor collector.  Valid values are integers between 1 and 100. Default is 60.
promotion-age=age Specifies the required age of an object must reach inside the nursery before been promoted to the old generation. This only can only be used with the split minor collector. Valid values are integers between 1 and 14. Default is 2.
(no-)cementing Enables or disables cementing.  This can dramatically shorten nursery collection times on some benchmarks where pinned objects are referred to from the major heap.
allow-synchronous-major This forbids the major collector from performing synchronous major collections.  The major collector might want to do a synchronous collection due to excessive fragmentation. Disabling this might trigger OutOfMemory error in situations that would otherwise not happen.
MONO_GC_DEBUG When using Mono with the SGen garbage collector this environment variable can be used to turn on various debugging features of the collector.  The value of this variable is a comma separated list of words.  Do not use these options in production.
number Sets the debug level to the specified number.
print-allowance After each major collection prints memory consumption for before and after the collection and the allowance for the minor collector, i.e. how much the heap is allowed to grow from minor collections before the next major collection is triggered.
print-pinning Gathers statistics on the classes whose objects are pinned in the nursery and for which global remset entries are added.  Prints those statistics when shutting down.
collect-before-allocs
check-remset-consistency This performs a remset consistency check at various opportunities, and also clears the nursery at collection time, instead of the default, when buffers are allocated (clear-at-gc).  The consistency check ensures that there are no major to minor references that are not on the remembered sets.
mod-union-consistency-check Checks that the mod-union cardtable is consistent before each finishing major collection pause.  This check is only applicable to concurrent major collectors.
check-mark-bits Checks that mark bits in the major heap are consistent at the end of each major collection.  Consistent mark bits mean that if an object is marked, all objects that it had references to must also be marked.
check-nursery-untag After garbage collections, check whether all vtable pointers are no longer tagged.
xdomain-checks Performs a check to make sure that no references are left to an unloaded AppDomain.
clear-at-tlab-creation Clears the nursery incrementally when the thread local allocation buffers (TLAB) are created.  The default setting clears the whole nursery at GC time.
debug-clear-at-tlab-creation Clears the nursery incrementally when the thread local allocation buffers (TLAB) are created, but at GC time fills it with the byte `0xff`, which should result in a crash more quickly if `clear-at-tlab-creation` doesn't work properly.
clear-at-gc This clears the nursery at GC time instead of doing it when the thread local allocation buffer (TLAB) is created.  The default is to clear the nursery at TLAB creation time.
disable-minor Don't do minor collections.  If the nursery is full, a major collection is triggered instead, unless it, too, is disabled.
disable-major Don't do major collections.
conservative-stack-mark Forces the GC to scan the stack conservatively, even if precise scanning is available.
no-managed-allocator Disables the managed allocator.
managed-allocator Enables the managed allocator.
check-scan-starts If set, does a plausibility check on the scan_starts before and after each collection
verify-nursery-at-minor-gc If set, does a complete object walk of the nursery at the start of each minor collection.
dump-nursery-at-minor-gc If set, dumps the contents of the nursery at the start of each minor collection. Requires verify-nursery-at-minor-gc to be set.
heap-dump=file Dumps the heap contents to the specified file.   To visualize the information, use the mono-heapviz tool.
binary-protocol=file Outputs the debugging output to the specified file.   For this to work, Mono needs to be compiled with the BINARY_PROTOCOL define on sgen-gc.c.   You can then use this command to explore the output sgen-grep-binprot 0x1234 0x5678 < file
nursery-canaries If set, objects allocated in the nursery are suffixed with a canary (guard) word, which is checked on each minor collection. Can be used to detect/debug heap corruption issues. This disables the usage of the managed allocator, because allocation from full aot code is inconsistent with this option. If the application is guaranteed not to use aot code, the managed allocator can be enabled back with managed-allocator option.
do-not-finalize(=classes) If enabled, finalizers will not be run.  Everything else will be unaffected: finalizable objects will still be put into the finalization queue where they survive until they're scheduled to finalize.  Once they're not in the queue anymore they will be collected regularly.  If a list of comma-separated class names is given, only objects from those classes will not be finalized.
log-finalizers Log verbosely around the finalization process to aid debugging.
MONO_GAC_PREFIX Provides a prefix the runtime uses to look for Global Assembly Caches.  Directories are separated by the platform path separator (colons on unix). MONO_GAC_PREFIX should point to the top directory of a prefixed install. Or to the directory provided in the gacutil /gacdir command. Example: /home/username/.mono:/usr/local/mono/
MONO_IOMAP (deprecated) Enabled some filename rewriting support to assist badly-written applications that hard-code Windows paths. It no longer works as of Mono 6.0.
MONO_LLVM When Mono is using the LLVM code generation backend you can use this environment variable to pass code generation options to the LLVM compiler.
MONO_MANAGED_WATCHER If set to "disabled", System.IO.FileSystemWatcher will use a file watcher implementation which silently ignores all the watching requests.  If set to any other value, System.IO.FileSystemWatcher will use the default managed implementation (slow). If unset, mono will try to use inotify, FAM, Gamin, kevent under Unix systems and native API calls on Windows, falling back to the managed implementation on error.
MONO_MESSAGING_PROVIDER Mono supports a plugin model for its implementation of System.Messaging making it possible to support a variety of messaging implementations (e.g. AMQP, ActiveMQ).  To specify which messaging implementation is to be used the evironement variable needs to be set to the full class name for the provider.  E.g. to use the RabbitMQ based AMQP implementation the variable should be set to:
Mono.Messaging.RabbitMQ.RabbitMQMessagingProvider,Mono.Messaging.RabbitMQ
MONO_NO_SMP If set causes the mono process to be bound to a single processor. This may be useful when debugging or working around race conditions.
MONO_NO_TLS Disable inlining of thread local accesses. Try setting this if you get a segfault early on in the execution of mono.
MONO_PATH Provides a search path to the runtime where to look for library files.   This is a tool convenient for debugging applications, but should not be used by deployed applications as it breaks the assembly loader in subtle ways. Directories are separated by the platform path separator (colons on unix). Example: /home/username/lib:/usr/local/mono/lib Relative paths are resolved based on the launch-time current directory. Alternative solutions to MONO_PATH include: installing libraries into the Global Assembly Cache (see gacutil(1)) or having the dependent libraries side-by-side with the main executable. For a complete description of recommended practices for application deployment, see http://www.mono-project.com/docs/getting-started/application-deployment/
MONO_SHARED_DIR If set its the directory where the ".wapi" handle state is stored. This is the directory where the Windows I/O Emulation layer stores its shared state data (files, events, mutexes, pipes).  By default Mono will store the ".wapi" directory in the users's home directory.
MONO_SHARED_HOSTNAME Uses the string value of this variable as a replacement for the host name when creating file names in the ".wapi" directory. This helps if the host name of your machine is likely to be changed when a mono application is running or if you have a .wapi directory shared among several different computers. Mono typically uses the hostname to create the files that are used to share state across multiple Mono processes.  This is done to support home directories that might be shared over the network.
MONO_STRICT_IO_EMULATION If set, extra checks are made during IO operations.  Currently, this includes only advisory locks around file writes.
MONO_TLS_PROVIDER This environment variable controls which TLS/SSL provider Mono will use.  The options are usually determined by the operating system where Mono was compiled and the configuration options that were used for it.
default Uses the default TLS stack that the Mono runtime was configured with. Usually this is configured to use Apple's SSL stack on Apple platforms, and Boring SSL on other platforms.
apple  Forces the use of the Apple SSL stack, only works on Apple platforms.
btls   Forces the use of the BoringSSL stack.    See https://opensource.google.com/projects/boringssl for more information about this stack.
legacy This is the old Mono stack, which only supports SSL and TLS up to version 1.0.   It is deprecated and will be removed in the future.
MONO_TLS_SESSION_CACHE_TIMEOUT The time, in seconds, that the SSL/TLS session cache will keep it's entry to avoid a new negotiation between the client and a server. Negotiation are very CPU intensive so an application-specific custom value may prove useful for small embedded systems. The default is 180 seconds.
MONO_THREADS_PER_CPU The minimum number of threads in the general threadpool will be MONO_THREADS_PER_CPU * number of CPUs. The default value for this variable is 1.
MONO_XMLSERIALIZER_THS Controls the threshold for the XmlSerializer to produce a custom serializer for a given class instead of using the Reflection-based interpreter.  The possible values are `no' to disable the use of a custom serializer or a number to indicate when the XmlSerializer should start serializing.   The default value is 50, which means that the a custom serializer will be produced on the 50th use.
MONO_X509_REVOCATION_MODE Sets the revocation mode used when validating a X509 certificate chain (https, ftps, smtps...).  The default is 'nocheck', which performs no revocation check at all. The other possible values are 'offline', which performs CRL check (not implemented yet) and 'online' which uses OCSP and CRL to verify the revocation status (not implemented yet).
NO_PROXY (Also no_proxy) If both HTTP_PROXY and NO_PROXY are set, NO_PROXY will be treated as a comma-separated list of "bypass" domains which will not be sent through the proxy. Domains in NO_PROXY may contain wildcards, as in "*.mono-project.com" or "build????.local". Not supported on Windows, Mac OS, iOS or Android.
MONO_ASPNET_NODELETE If set to any value, temporary source files generated by ASP.NET support classes will not be removed. They will be kept in the user's temporary directory.
MONO_DEBUG If set, enables some features of the runtime useful for debugging. This variable should contain a comma separated list of debugging options.  Currently, the following options are supported:
align-small-structs Enables small structs alignment to 4/8 bytes.
arm-use-fallback-tls When this option is set on ARM, a fallback thread local store will be used instead of the default fast thread local storage primitives.