### Install and Activate Latest Development SDK (sdk-main-64bit)

Source: https://github.com/emscripten-core/emscripten/blob/main/site/source/docs/tools_reference/emsdk.md

Build from the very latest sources by installing and activating `sdk-main-64bit`. This requires installing git first if not already present.

```bash
# Install git (Skip if the system already has it).
./emsdk install git-1.8.3

# Clone+pull the latest emscripten-core/emscripten/main.
./emsdk install sdk-main-64bit

# Set this as the active version.
./emsdk activate sdk-main-64bit
```

--------------------------------

### Create Example Executable

Source: https://github.com/emscripten-core/emscripten/blob/main/test/third_party/zlib/CMakeLists.txt

Builds an executable named 'example' from 'example.c' and links it against the zlib library. Also adds a test for this executable.

```cmake
add_executable(example example.c)
target_link_libraries(example zlib)
add_test(example example)
```

--------------------------------

### Install a Specific Tool or SDK Version

Source: https://github.com/emscripten-core/emscripten/blob/main/site/source/docs/tools_reference/emsdk.md

Download and install a new tool or SDK version using its name.

```bash
./emsdk install <tool/sdk name>
```

```bash
./emsdk install sdk-1.38.21-64bit
```

--------------------------------

### Build Example with Embind Asyncify or JSPI

Source: https://github.com/emscripten-core/emscripten/blob/main/site/source/docs/porting/asyncify.md

Build command for a C++ example using Embind, enabling either Asyncify or JSPI.

```default
emcc -O3 example.cpp -lembind -s<ASYNCIFY or JSPI>

```

--------------------------------

### Install and Activate Specific SDK Version

Source: https://github.com/emscripten-core/emscripten/blob/main/site/source/docs/tools_reference/emsdk.md

Install a specific SDK version and then activate it to set it as the current compiler configuration.

```bash
./emsdk install 4.0.7
./emsdk activate 4.0.7
```

--------------------------------

### Set Binaryen Root Directory

Source: https://github.com/emscripten-core/emscripten/blob/main/site/source/docs/building_from_source/configuring_emscripten_settings.md

Example of how to set the BINARYEN_ROOT variable in the .emscripten file to point to your Binaryen installation directory. Use forward slashes for paths.

```text
BINARYEN_ROOT = 'C:\\tools\\binaryen\\'
```

--------------------------------

### Install zlib Libraries and Headers

Source: https://github.com/emscripten-core/emscripten/blob/main/test/third_party/zlib/CMakeLists.txt

Installs the zlib library targets (runtime, archive, library) and public headers to their respective destinations if installation is not skipped.

```cmake
if(NOT SKIP_INSTALL_LIBRARIES AND NOT SKIP_INSTALL_ALL )
    install(TARGETS zlib
        RUNTIME DESTINATION bin
        ARCHIVE DESTINATION lib
        LIBRARY DESTINATION lib )
endif()
if(NOT SKIP_INSTALL_HEADERS AND NOT SKIP_INSTALL_ALL )
    install(FILES ${ZLIB_PUBLIC_HDRS} DESTINATION include)
endif()
if(NOT SKIP_INSTALL_FILES AND NOT SKIP_INSTALL_ALL )
    install(FILES zlib.3 DESTINATION share/man/man3)
endif()
```

--------------------------------

### Install and Activate SDK Asserts Version

Source: https://github.com/emscripten-core/emscripten/blob/main/site/source/docs/tools_reference/emsdk.md

Install and activate an SDK version built with additional runtime checks for debugging.

```bash
./emsdk install 4.0.7-asserts
./emsdk activate 4.0.7-asserts
```

--------------------------------

### List Installed SDKs and Tools

Source: https://github.com/emscripten-core/emscripten/blob/main/site/source/docs/tools_reference/emsdk.md

Display a list of all installed tools and SDK versions, indicating which are currently active.

```bash
./emsdk list
```

--------------------------------

### Install Man Pages

Source: https://github.com/emscripten-core/emscripten/blob/main/test/third_party/openjpeg/codec/CMakeLists.txt

Installs the man pages for the OpenJPEG command-line tools to the specified installation directory.

```cmake
INSTALL(
  FILES       ../doc/man/man1/image_to_j2k.1
              ../doc/man/man1/j2k_dump.1
              ../doc/man/man1/j2k_to_image.1
  DESTINATION ${OPENJPEG_INSTALL_MAN_DIR}/man1)
#
```

--------------------------------

### Update SDK Registry and Install Latest SDK

Source: https://github.com/emscripten-core/emscripten/blob/main/site/source/docs/tools_reference/emsdk.md

Fetch the latest tool registry and then download and install the most recent SDK release.

```bash
# Fetch the latest registry of available tools.
./emsdk update

# Download and install the latest SDK tools.
./emsdk install latest

# Set up the compiler configuration to point to the "latest" SDK.
./emsdk activate latest
```

--------------------------------

### Install and Activate Tip-Of-Tree (tot) SDK

Source: https://github.com/emscripten-core/emscripten/blob/main/site/source/docs/tools_reference/emsdk.md

To use the latest development changes, install and activate the `tot` version, which is continuously built with recent Emscripten and LLVM updates.

```bash
./emsdk install tot
./emsdk activate tot
```

--------------------------------

### Emscripten Compiler Configuration File Example (Windows)

Source: https://github.com/emscripten-core/emscripten/blob/main/site/source/docs/tools_reference/emsdk.md

Example of a .emscripten configuration file on Windows, specifying paths to LLVM and Node.js.

```python
import os
LLVM_ROOT='C:/Program Files/Emscripten/clang/e1.21.0_64bit'
NODE_JS='C:/Program Files/Emscripten/node/0.10.17_64bit/node.exe'
```

--------------------------------

### List and Install Old Emscripten SDK Versions

Source: https://github.com/emscripten-core/emscripten/blob/main/site/source/docs/tools_reference/emsdk.md

Retrieve a list of archived tool and SDK versions using `list --old`. Install a specific archived version using `install <name_of_tool>` and then activate it.

```bash
# Get list of the old versions of the tool.
./emsdk list --old

# Install the required version.
./emsdk install <name_of_tool>

# Activate required version.
./emsdk activate <name_of_tool>
```

--------------------------------

### Example Executable Build

Source: https://github.com/emscripten-core/emscripten/blob/main/test/third_party/freealut/CMakeLists.txt

Builds the 'hello_world' example executable. It links against OpenAL, additional libraries, and either the static or shared 'alut' library depending on the EMSCRIPTEN build flag.

```cmake
ADD_EXECUTABLE(hello_world examples/hello_world.c)
    if (EMSCRIPTEN)
      TARGET_LINK_LIBRARIES(hello_world ${OPENAL_LIB} ${ADD_LIBS} alut_static)
    else()
      TARGET_LINK_LIBRARIES(hello_world ${OPENAL_LIB} ${ADD_LIBS} alut)
    endif()
```

--------------------------------

### Update Emscripten SDK and Install New Versions

Source: https://github.com/emscripten-core/emscripten/blob/main/site/source/docs/tools_reference/emsdk.md

First, fetch the latest registry of available tools and SDKs using `update`. Then, install a specific new version using `install <tool/sdk name>`.

```bash
# Fetch the latest registry of available tools.
./emsdk update

# Download and install the specified new version.
./emsdk install <tool/sdk name>
```

--------------------------------

### Install Library Files

Source: https://github.com/emscripten-core/emscripten/blob/main/test/third_party/bullet/src/BulletMultiThreaded/GpuSoftBodySolvers/OpenCL/MiniCL/CMakeLists.txt

Configures installation rules for the 'BulletSoftBodySolvers_OpenCL_Mini' library, including destination paths and handling for macOS frameworks.

```cmake
IF (INSTALL_LIBS)
	IF (NOT INTERNAL_CREATE_DISTRIBUTABLE_MSVC_PROJECTFILES)
		IF (${CMAKE_MAJOR_VERSION}.${CMAKE_MINOR_VERSION} GREATER 2.5)
			IF (APPLE AND BUILD_SHARED_LIBS AND FRAMEWORK)
				INSTALL(TARGETS BulletSoftBodySolvers_OpenCL_Mini DESTINATION .)
			ELSE (APPLE AND BUILD_SHARED_LIBS AND FRAMEWORK)
				INSTALL(TARGETS BulletSoftBodySolvers_OpenCL_Mini DESTINATION lib${LIB_SUFFIX})
#headers are already installed by BulletMultiThreaded library
			ENDIF (APPLE AND BUILD_SHARED_LIBS AND FRAMEWORK)
		ENDIF (${CMAKE_MAJOR_VERSION}.${CMAKE_MINOR_VERSION} GREATER 2.5)

		IF (APPLE AND BUILD_SHARED_LIBS AND FRAMEWORK)
			SET_TARGET_PROPERTIES(BulletSoftBodySolvers_OpenCL_Mini PROPERTIES FRAMEWORK true)
			SET_TARGET_PROPERTIES(BulletSoftBodySolvers_OpenCL_Mini PROPERTIES PUBLIC_HEADER "${BulletSoftBodyOpenCLSolvers_HDRS}")
		ENDIF (APPLE AND BUILD_SHARED_LIBS AND FRAMEWORK)
	ENDIF (NOT INTERNAL_CREATE_DISTRIBUTABLE_MSVC_PROJECTFILES)
ENDIF (INSTALL_LIBS)
```

--------------------------------

### Install and Activate MinGW Compiler Toolchain

Source: https://github.com/emscripten-core/emscripten/blob/main/site/source/docs/building_from_source/toolchain_what_is_needed.md

Use these commands to install and activate the MinGW compiler toolchain for SDK users on Windows.

```bash
emsdk install mingw-4.6.2-32bit
emsdk activate mingw-4.6.2-32bit
```

--------------------------------

### Playfile Example Executable Build

Source: https://github.com/emscripten-core/emscripten/blob/main/test/third_party/freealut/CMakeLists.txt

Builds the 'playfile' example executable. Similar to 'hello_world', it links against OpenAL, additional libraries, and the appropriate 'alut' library based on the EMSCRIPTEN flag.

```cmake
ADD_EXECUTABLE(playfile examples/playfile.c)
    if (EMSCRIPTEN)
      TARGET_LINK_LIBRARIES(playfile ${OPENAL_LIB} ${ADD_LIBS} alut_static)
    else()
      TARGET_LINK_LIBRARIES(playfile ${OPENAL_LIB} ${ADD_LIBS} alut)
    endif()
```

--------------------------------

### Install GCC and CMake on Linux

Source: https://github.com/emscripten-core/emscripten/blob/main/site/source/docs/building_from_source/toolchain_what_is_needed.md

Commands to install the GCC compiler and CMake build system on Linux distributions using apt-get.

```bash
#Install gcc
sudo apt-get install build-essential
# Install cmake
sudo apt-get install cmake
```

--------------------------------

### Emscripten Compiler Configuration File Example (Linux)

Source: https://github.com/emscripten-core/emscripten/blob/main/site/source/docs/tools_reference/emsdk.md

Example of a .emscripten configuration file on Linux, specifying Node.js and LLVM paths.

```python
import os
NODE_JS = 'node'
LLVM_ROOT='/home/ubuntu/emsdk/upstream/bin'
```

--------------------------------

### Install Sphinx Dependencies

Source: https://github.com/emscripten-core/emscripten/blob/main/site/source/docs/site/about.md

Ensures the correct version of Sphinx is installed for building the site. Run this command in the Emscripten site directory.

```default
pip install -r requirements-dev.txt
```

--------------------------------

### Configure Installation Directories and Pkgconfig

Source: https://github.com/emscripten-core/emscripten/blob/main/test/third_party/bullet/CMakeLists.txt

This snippet configures installation directories for libraries and headers if INSTALL_LIBS is enabled. It also sets up the pkgconfig file for Linux systems.

```cmake
IF(INSTALL_LIBS)
	SET (LIB_SUFFIX "" CACHE STRING "Define suffix of directory name (32/64)" )
	SET (LIB_DESTINATION "${CMAKE_INSTALL_PREFIX}/lib${LIB_SUFFIX}" CACHE STRING "Library directory name")
	## the following are directories where stuff will be installed to
	SET(INCLUDE_INSTALL_DIR "${CMAKE_INSTALL_PREFIX}/include/bullet/" CACHE PATH "The subdirectory to the header prefix")
	SET(PKGCONFIG_INSTALL_PREFIX "${CMAKE_INSTALL_PREFIX}/lib${LIB_SUFFIX}/pkgconfig/" CACHE STRING "Base directory for pkgconfig files")
	IF(NOT WIN32)
	  CONFIGURE_FILE(${CMAKE_CURRENT_SOURCE_DIR}/bullet.pc.cmake ${CMAKE_CURRENT_BINARY_DIR}/bullet.pc @ONLY)
  	INSTALL(
	    FILES
    	${CMAKE_CURRENT_BINARY_DIR}/bullet.pc
    	DESTINATION
    	${PKGCONFIG_INSTALL_PREFIX})
	ENDIF(NOT WIN32)
ENDIF(INSTALL_LIBS)
```

--------------------------------

### Shared Library Build and Installation

Source: https://github.com/emscripten-core/emscripten/blob/main/test/third_party/freealut/CMakeLists.txt

Defines the shared 'alut' library, sets its version properties, links necessary libraries, and installs the target library and header files.

```cmake
ADD_LIBRARY(alut SHARED ${ALUT_SOURCES})
SET_TARGET_PROPERTIES(alut PROPERTIES VERSION ${VERSION} SOVERSION ${MAJOR_VERSION})
TARGET_LINK_LIBRARIES(alut ${OPENAL_LIB} ${ADD_LIBS})

INSTALL_TARGETS(/lib alut)
INSTALL_FILES(/include/AL FILES include/AL/alut.h)
```

--------------------------------

### Install a tip-of-tree Emscripten build

Source: https://github.com/emscripten-core/emscripten/blob/main/site/source/docs/getting_started/downloads.md

Install a tip-of-tree (tot) build, which represents the very latest code that passes integration tests. This requires specifying the backend explicitly.

```bash
./emsdk install tot
```

--------------------------------

### Install Latest Emscripten Tip-of-Tree Binaries

Source: https://github.com/emscripten-core/emscripten/blob/main/site/source/docs/contributing/developers_guide.md

Installs and activates the latest 'tip-of-tree' binaries for Emscripten development. These are necessary for running Emscripten and its core components.

```bash
emsdk install tot
emsdk activate tot
```

--------------------------------

### Install MiniCL Library and Headers

Source: https://github.com/emscripten-core/emscripten/blob/main/test/third_party/bullet/src/MiniCL/CMakeLists.txt

Configures the installation of the MiniCL library and its header files. This section includes conditional logic for different platforms and build configurations.

```cmake
IF (INSTALL_LIBS)
	IF (NOT INTERNAL_CREATE_DISTRIBUTABLE_MSVC_PROJECTFILES)
		#INSTALL of other files requires CMake 2.6
		IF (${CMAKE_MAJOR_VERSION}.${CMAKE_MINOR_VERSION} GREATER 2.5)
#			IF(INSTALL_EXTRA_LIBS)
				IF (APPLE AND BUILD_SHARED_LIBS AND FRAMEWORK)
					INSTALL(TARGETS MiniCL DESTINATION .)
				ELSE (APPLE AND BUILD_SHARED_LIBS AND FRAMEWORK)
				INSTALL(TARGETS MiniCL DESTINATION lib${LIB_SUFFIX})
					INSTALL(DIRECTORY
${CMAKE_CURRENT_SOURCE_DIR} DESTINATION ${INCLUDE_INSTALL_DIR} FILES_MATCHING
PATTERN "*.h"  PATTERN ".svn" EXCLUDE PATTERN "CMakeFiles" EXCLUDE)
				ENDIF (APPLE AND BUILD_SHARED_LIBS AND FRAMEWORK)
#			ENDIF (INSTALL_EXTRA_LIBS)
		ENDIF (${CMAKE_MAJOR_VERSION}.${CMAKE_MINOR_VERSION} GREATER 2.5)
	ENDIF (NOT INTERNAL_CREATE_DISTRIBUTABLE_MSVC_PROJECTFILES)
ENDIF (INSTALL_LIBS)
```

--------------------------------

### Install and activate latest Emscripten SDK tools

Source: https://github.com/emscripten-core/emscripten/blob/main/site/source/docs/getting_started/downloads.md

Fetch the latest SDK tools from GitHub, install them, and activate the 'latest' SDK version. This sets the tools as active for the current user.

```bash
./emsdk install latest
./emsdk activate latest
source ./emsdk_env.sh
```

--------------------------------

### Verify Emscripten Installation

Source: https://github.com/emscripten-core/emscripten/blob/main/site/source/docs/getting_started/Tutorial.md

Run this command to check if Emscripten is installed correctly and accessible from your command line. If you see warnings about missing tools, refer to the verification guide.

```bash
./emcc -v
```

--------------------------------

### Quick Toolchain Profiling Example

Source: https://github.com/emscripten-core/emscripten/blob/main/site/source/docs/optimizing/Profiling-Toolchain.md

Run this sequence to enable profiling, compile a project, and generate a profiling report. The output is an HTML file showing toolchain performance.

```bash
cd path/to/emscripten
export EMPROFILE=1
emcc test/hello_world.c -O3 -o a.html
emprofile
```

--------------------------------

### Run Multiple Browser Tests with Wildcards

Source: https://github.com/emscripten-core/emscripten/blob/main/site/source/docs/getting_started/test-suite.md

Use wildcards to run a group of browser tests. This example runs all tests starting with 'browser.test_sdl2'.

```bash
# run all SDL2 browser tests
test/runner browser.test_sdl2*
```

--------------------------------

### Building Projects with Mixed Optimizations

Source: https://github.com/emscripten-core/emscripten/blob/main/site/source/docs/compiling/Building-Projects.md

This example shows how to apply different optimization levels to specific source files, optimizing one for size and others using a higher optimization level.

```bash
# Optimize the first file for size, and the rest using `-O2`.
emcc -Oz a.cpp -c -o a.o
emcc -O2 b.cpp -c -o b.o
emcc -O2 a.o b.o -o project.js
```

--------------------------------

### Emscripten Check Output Example

Source: https://github.com/emscripten-core/emscripten/blob/main/site/source/docs/building_from_source/verify_emscripten_environment.md

This output indicates an incorrect LLVM version for clang, suggesting a potential issue with the Emscripten toolchain setup.

```none
emcc (Emscripten GCC-like replacement + linker emulating GNU ld) 1.21.0
shared:INFO: (Emscripten: Running sanity checks)
emcc: warning: LLVM version for clang executable "/usr/bin/clang" appears incorrect (seeing "16.0", expected "18") [-Wversion-check]

```

--------------------------------

### Hello World Example in ALUT

Source: https://github.com/emscripten-core/emscripten/blob/main/test/third_party/freealut/doc/alut.html

A basic ALUT program that plays a 'Hello, world!' sound. Error checks are omitted for simplicity. Ensure ALUT is initialized with alutInit() and exited with alutExit().

```c
#include <stdlib.h>
#include <AL/alut.h>

int
main (int argc, char **argv)
{
  ALuint helloBuffer, helloSource;
  alutInit (&argc, argv);
  helloBuffer = alutCreateBufferHelloWorld ();
  alGenSources (1, &helloSource);
  alSourcei (helloSource, AL_BUFFER, helloBuffer);
  alSourcePlay (helloSource);
  alutSleep (1);
  alutExit ();
  return EXIT_SUCCESS;
}
```

--------------------------------

### Install Poppler Qt4 Target

Source: https://github.com/emscripten-core/emscripten/blob/main/test/third_party/poppler/qt4/src/CMakeLists.txt

Installs the poppler-qt4 library to the appropriate runtime, library, and archive destinations. This makes the library available after installation.

```cmake
install(TARGETS poppler-qt4 RUNTIME DESTINATION bin LIBRARY DESTINATION lib${LIB_SUFFIX} ARCHIVE DESTINATION lib${LIB_SUFFIX})
```

--------------------------------

### Create and Navigate to Build Directory

Source: https://github.com/emscripten-core/emscripten/blob/main/system/lib/llvm-libc/config/windows/README.md

Create an empty directory for building LLVM libc and change the current directory to it.

```bash
mkdir libc-build
cd libc-build
```

--------------------------------

### Check CMake Installation

Source: https://github.com/emscripten-core/emscripten/blob/main/site/source/docs/building_from_source/toolchain_what_is_needed.md

Verify if CMake is installed.

```bash
cmake
```

--------------------------------

### SDL Hello World Example

Source: https://github.com/emscripten-core/emscripten/blob/main/site/source/docs/getting_started/Tutorial.md

A C program demonstrating basic SDL initialization, surface manipulation for drawing a colored square, and displaying it on screen. This example is intended to be compiled with Emscripten.

```c
// Copyright 2011 The Emscripten Authors.  All rights reserved.
// Emscripten is available under two separate licenses, the MIT license and the
// University of Illinois/NCSA Open Source License.  Both these licenses can be
// found in the LICENSE file.

#include <stdio.h>
#include <SDL/SDL.h>

#ifdef __EMSCRIPTEN__
#include <emscripten.h>
#endif

int main(int argc, char** argv) {
  printf("Hello, world!\n");

  SDL_Init(SDL_INIT_VIDEO);
  SDL_Surface *screen = SDL_SetVideoMode(256, 256, 32, SDL_SWSURFACE);

#ifdef TEST_SDL_LOCK_OPTS
  EM_ASM("SDL.defaults.copyOnLock = false; SDL.defaults.discardOnLock = true; SDL.defaults.opaqueFrontBuffer = false;");
#endif

  if (SDL_MUSTLOCK(screen)) SDL_LockSurface(screen);
  for (int i = 0; i < 256; i++) {
    for (int j = 0; j < 256; j++) {
#ifdef TEST_SDL_LOCK_OPTS
      // Alpha behaves like in the browser, so write proper opaque pixels.
      int alpha = 255;
#else
      // To emulate native behavior with blitting to screen, alpha component is ignored. Test that it is so by outputting
      // data (and testing that it does get discarded)
      int alpha = (i+j) % 255;
#endif
      *((Uint32*)screen->pixels + i * 256 + j) = SDL_MapRGBA(screen->format, i, j, 255-i, alpha);
    }
  }
  if (SDL_MUSTLOCK(screen)) SDL_UnlockSurface(screen);
  SDL_Flip(screen);

  printf("you should see a smoothly-colored square - no sharp lines but the square borders!\n");
  printf("and here is some text that should be HTML-friendly: amp: |&| double-quote: |\"| quote: |'| less-than, greater-than, html-like tags: |<cheez></cheez>|\nanother line.\n");

  SDL_Quit();

  return 0;
}

```

--------------------------------

### FS.init(input, output, error)

Source: https://github.com/emscripten-core/emscripten/blob/main/site/source/docs/api_reference/Filesystem-API.md

Sets up standard I/O devices (stdin, stdout, stderr) using provided callback functions for input and output operations.

```APIDOC
### FS.init(input, output, error)

Sets up standard I/O devices for `stdin`, `stdout`, and `stderr`.

The devices are set up using the following (optional) callbacks. If any of the callbacks throw an exception, it will be caught and handled as if the device malfunctioned.

* **Arguments:**
  * **input** – Input callback. This will be called with no parameters whenever the program attempts to read from `stdin`. It should return an ASCII character code when data is available, or `null` when it isn’t.
  * **output** – Output callback. This will be called with an ASCII character code whenever the program writes to `stdout`. It may also be called with `null` to flush the output.
  * **error** – Error callback. This is similar to `output`, except it is called when data is written to `stderr`.
```

--------------------------------

### Change Starting Symbol in PLY

Source: https://github.com/emscripten-core/emscripten/blob/main/third_party/ply/doc/ply.html

Specifies a starting symbol for the grammar using a 'start' specifier or as an argument to yacc(). Useful for debugging or subsetting grammars.

```python
start = 'foo'

def p_bar(p):
    'bar : A B'

# This is the starting rule due to the start specifier above
def p_foo(p):
    'foo : bar X'
...
```

```python
yacc.yacc(start='foo')
```

--------------------------------

### Compiling and Running Async Fetch Example

Source: https://github.com/emscripten-core/emscripten/blob/main/site/source/docs/porting/asyncify.md

Instructions for compiling the C code using Asyncify or JSPI and the necessary steps to run it, which involves using a local webserver.

```default
emcc example.c -O3 -o a.html -s<ASYNCIFY or JSPI>
```

--------------------------------

### Start ETW Profiling with WPR

Source: https://github.com/emscripten-core/emscripten/blob/main/system/lib/mimalloc/src/prim/windows/readme.md

Use Windows Performance Recorder (WPR) to start profiling. This command starts recording with the specified profile and file mode.

```bash
> wpr -start src\prim\windows\etw-mimalloc.wprp -filemode
```

--------------------------------

### Initializing standard I/O devices

Source: https://github.com/emscripten-core/emscripten/blob/main/site/source/docs/api_reference/Filesystem-API.md

Set up standard I/O devices for stdin, stdout, and stderr using custom callbacks. This configuration should be done before the main `run()` method, typically within `Module.preRun`.

```javascript
FS.init(input, output, error);
```

--------------------------------

### Build C Library and Link with Main File

Source: https://context7.com/emscripten-core/emscripten/llms.txt

Configure, build, and install a C library using Emscripten tools, then link it with a main application file.

```bash
emconfigure ./configure --prefix=$(pwd)/install
```

```bash
emmake make install
```

```bash
emcc -O2 main.c -Linstall/lib -lmylib -o app.js
```

--------------------------------

### Check GCC/G++ Installation

Source: https://github.com/emscripten-core/emscripten/blob/main/site/source/docs/building_from_source/toolchain_what_is_needed.md

Verify if GCC and G++ compilers are installed.

```bash
gcc --version
g++
```

--------------------------------

### CoreMark Reporting Example

Source: https://github.com/emscripten-core/emscripten/blob/main/test/third_party/coremark/README.md

Example of a CoreMark performance result report.

```text
CoreMark 1.0 : 128 / GCC 4.1.2 -O2 -fprofile-use / Heap in TCRAM / FORK:2 
or
CoreMark 1.0 : 1400 / GCC 3.4 -O4 

```

--------------------------------

### Install BulletDynamics Library and Headers

Source: https://github.com/emscripten-core/emscripten/blob/main/test/third_party/bullet/src/BulletDynamics/CMakeLists.txt

Configures the installation rules for the BulletDynamics library and its headers. This includes handling different installation paths based on platform and build type (static/shared).

```cmake
IF (INSTALL_LIBS)
	IF (NOT INTERNAL_CREATE_DISTRIBUTABLE_MSVC_PROJECTFILES)
		IF (${CMAKE_MAJOR_VERSION}.${CMAKE_MINOR_VERSION} GREATER 2.5)
			IF (APPLE AND BUILD_SHARED_LIBS AND FRAMEWORK)
				INSTALL(TARGETS BulletDynamics DESTINATION .)
			ELSE (APPLE AND BUILD_SHARED_LIBS AND FRAMEWORK)
				INSTALL(TARGETS BulletDynamics DESTINATION lib${LIB_SUFFIX})
				INSTALL(DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR}
DESTINATION ${INCLUDE_INSTALL_DIR} FILES_MATCHING PATTERN "*.h"  PATTERN
".svn" EXCLUDE PATTERN "CMakeFiles" EXCLUDE)
				INSTALL(FILES ../btBulletDynamicsCommon.h
DESTINATION ${INCLUDE_INSTALL_DIR}/BulletDynamics)
			ENDIF (APPLE AND BUILD_SHARED_LIBS AND FRAMEWORK)
		ENDIF (${CMAKE_MAJOR_VERSION}.${CMAKE_MINOR_VERSION} GREATER 2.5)

		IF (APPLE AND BUILD_SHARED_LIBS AND FRAMEWORK)
			SET_TARGET_PROPERTIES(BulletDynamics PROPERTIES FRAMEWORK true)
			SET_TARGET_PROPERTIES(BulletDynamics PROPERTIES PUBLIC_HEADER "${Root_HDRS}")
			# Have to list out sub-directories manually:
			SET_PROPERTY(SOURCE ${ConstraintSolver_HDRS} PROPERTY MACOSX_PACKAGE_LOCATION Headers/ConstraintSolver)
			SET_PROPERTY(SOURCE ${Dynamics_HDRS} PROPERTY MACOSX_PACKAGE_LOCATION Headers/Dynamics)
			SET_PROPERTY(SOURCE ${Vehicle_HDRS} PROPERTY MACOSX_PACKAGE_LOCATION Headers/Vehicle)
			SET_PROPERTY(SOURCE ${Character_HDRS} PROPERTY MACOSX_PACKAGE_LOCATION Headers/Character)
				
		ENDIF (APPLE AND BUILD_SHARED_LIBS AND FRAMEWORK)
	ENDIF (NOT INTERNAL_CREATE_DISTRIBUTABLE_MSVC_PROJECTFILES)
ENDIF (INSTALL_LIBS)
```

--------------------------------

### Set Start Rule for PLY Grammar

Source: https://github.com/emscripten-core/emscripten/blob/main/third_party/ply/doc/internal.html

Specifies the starting rule for the grammar. If omitted, the first added production becomes the start rule. Must be called after all productions are added.

```python
g.set_start(start='expr')
```

--------------------------------

### Install leb128 library

Source: https://github.com/emscripten-core/emscripten/blob/main/third_party/leb128/README.md

Install the leb128 Python package using pip.

```shell
$ pip3 install leb128
```

--------------------------------

### PROXYFS Example

Source: https://github.com/emscripten-core/emscripten/blob/main/site/source/docs/api_reference/Filesystem-API.md

Demonstrates how to mount another module's file system using PROXYFS, allowing shared access without data copying.

```APIDOC
## PROXYFS

This allows a module to mount another module’s file system. This is useful when separate modules need to share a file system without manually syncing file contents. For example:

```js
// Module 2 can use the path "/fs1" to access and modify Module 1's filesystem
module2.FS.mkdir("/fs1");
module2.FS.mount(module2.PROXYFS, {
    root: "/",
    fs: module1.FS
}, "/fs1");
```
```

--------------------------------

### Install OpenCL Soft Body Solver Library on Apple

Source: https://github.com/emscripten-core/emscripten/blob/main/test/third_party/bullet/src/BulletMultiThreaded/GpuSoftBodySolvers/OpenCL/Apple/CMakeLists.txt

Configures installation rules for the OpenCL soft body solver library on Apple, handling framework builds and standard library installations.

```cmake
IF (INSTALL_LIBS)
	IF (NOT INTERNAL_CREATE_DISTRIBUTABLE_MSVC_PROJECTFILES)
		IF (${CMAKE_MAJOR_VERSION}.${CMAKE_MINOR_VERSION} GREATER 2.5)
			IF (APPLE AND BUILD_SHARED_LIBS AND FRAMEWORK)
				INSTALL(TARGETS BulletSoftBodySolvers_OpenCL_Apple  DESTINATION .)
			ELSE (APPLE AND BUILD_SHARED_LIBS AND FRAMEWORK)
				INSTALL(TARGETS BulletSoftBodySolvers_OpenCL_Apple  DESTINATION lib${LIB_SUFFIX})
#headers are already installed by BulletMultiThreaded library
			ENDIF (APPLE AND BUILD_SHARED_LIBS AND FRAMEWORK)
		ENDIF (${CMAKE_MAJOR_VERSION}.${CMAKE_MINOR_VERSION} GREATER 2.5)

		IF (APPLE AND BUILD_SHARED_LIBS AND FRAMEWORK)
			SET_TARGET_PROPERTIES(BulletSoftBodySolvers_OpenCL_Apple PROPERTIES FRAMEWORK true)
			SET_TARGET_PROPERTIES(BulletSoftBodySolvers_OpenCL_Apple PROPERTIES PUBLIC_HEADER "${BulletSoftBodyOpenCLSolvers_HDRS}")
		ENDIF (APPLE AND BUILD_SHARED_LIBS AND FRAMEWORK)
	ENDIF (NOT INTERNAL_CREATE_DISTRIBUTABLE_MSVC_PROJECTFILES)
ENDIF (INSTALL_LIBS)
```

--------------------------------

### Serve Emscripten Website Locally

Source: https://github.com/emscripten-core/emscripten/blob/main/docs/process.md

Starts a local web server to view the built emscripten.org website. Browse to http://localhost:8000/ to view.

```bash
python3 -m http.server 8000 -d site/build/html
```

--------------------------------

### Consistent Optimization Flags for Building Projects

Source: https://github.com/emscripten-core/emscripten/blob/main/site/source/docs/compiling/Building-Projects.md

This example shows the recommended approach for building projects by applying the same optimization flags during both the object file compilation and the final linking stage.

```bash
emcc -O2 a.cpp -c -o a.o
emcc -O2 b.cpp -c -o b.o
emcc -O2 a.o b.o -o project.js
```

--------------------------------

### Install Poppler GLib Target

Source: https://github.com/emscripten-core/emscripten/blob/main/test/third_party/poppler/glib/CMakeLists.txt

Installs the 'poppler-glib' target, specifying runtime, library, and archive destinations.

```cmake
install(TARGETS poppler-glib RUNTIME DESTINATION bin LIBRARY DESTINATION lib${LIB_SUFFIX} ARCHIVE DESTINATION lib${LIB_SUFFIX})
```

--------------------------------

### Configure Box2D Hello World Project

Source: https://github.com/emscripten-core/emscripten/blob/main/test/third_party/box2d/HelloWorld/CMakeLists.txt

Sets up the build environment for the Hello World example using CMake. It includes the Box2D source directory, defines the executable, and links the Box2D library.

```cmake
include_directories (${Box2D_SOURCE_DIR})
add_executable(HelloWorld HelloWorld.cpp)
target_link_libraries (HelloWorld Box2D)
```

--------------------------------

### Install Poppler GLib Headers

Source: https://github.com/emscripten-core/emscripten/blob/main/test/third_party/poppler/glib/CMakeLists.txt

Installs the public and generated header files for Poppler GLib to the include directory.

```cmake
install(FILES
  ${poppler_glib_public_headers}
  ${CMAKE_CURRENT_BINARY_DIR}/poppler-enums.h
  ${CMAKE_CURRENT_BINARY_DIR}/poppler-features.h
  DESTINATION include/poppler/glib)
```

--------------------------------

### alutLoadMemoryHelloWorld

Source: https://github.com/emscripten-core/emscripten/blob/main/test/third_party/freealut/doc/alut.html

Loads a pre-recorded 'Hello, world!' sound into OpenAL-compatible data. The sound data is guaranteed to be in a standard OpenAL format.

```APIDOC
## alutLoadMemoryHelloWorld

### Description
Loads the sound of someone saying 'Hello, world!' into a newly allocated buffer. The sound data is guaranteed to be in a standard OpenAL format, with a sample frequency chosen by the ALUT implementation.

### Synopsis
```c
ALvoid *alutLoadMemoryHelloWorld (ALenum *format,
                                  ALsizei *size,
                                  ALfloat *frequency);
```

### Parameters
- **format** (ALenum *) - Pointer to an ALenum to receive the sound format (e.g., AL_FORMAT_MONO8, AL_FORMAT_STEREO16).
- **size** (ALsizei *) - Pointer to an ALsizei to receive the size of the sound data in bytes.
- **frequency** (ALfloat *) - Pointer to an ALfloat to receive the sample frequency of the sound.

### Return Value
On success, returns a pointer to a newly allocated memory area containing the sound data. This memory should be freed by the caller when no longer needed. Returns NULL on failure.

### Errors
- ALUT_ERROR_OUT_OF_MEMORY: ALUT ran out of memory.
- ALUT_ERROR_INVALID_OPERATION: ALUT has not been initialized.
- ALUT_ERROR_NO_CURRENT_CONTEXT: There is no current AL context.
- ALUT_ERROR_AL_ERROR_ON_ENTRY: An AL error occurred before the function call.
- ALUT_ERROR_ALC_ERROR_ON_ENTRY: An ALC error occurred before the function call.
```

--------------------------------

### Create 64-bit Example and minigzip Executables

Source: https://github.com/emscripten-core/emscripten/blob/main/test/third_party/zlib/CMakeLists.txt

Conditionally creates 64-bit versions of 'example' and 'minigzip' executables if HAVE_OFF64_T is defined. These are compiled with '-D_FILE_OFFSET_BITS=64' to enable 64-bit file offset support.

```cmake
if(HAVE_OFF64_T)
    add_executable(example64 example.c)
    target_link_libraries(example64 zlib)
    set_target_properties(example64 PROPERTIES COMPILE_FLAGS "-D_FILE_OFFSET_BITS=64")
    add_test(example64 example64)

    add_executable(minigzip64 minigzip.c)
    target_link_libraries(minigzip64 zlib)
    set_target_properties(minigzip64 PROPERTIES COMPILE_FLAGS "-D_FILE_OFFSET_BITS=64")
endif()
```

--------------------------------

### Conditional Installation of BulletSoftBody

Source: https://github.com/emscripten-core/emscripten/blob/main/test/third_party/bullet/src/BulletSoftBody/CMakeLists.txt

Handles the installation of the BulletSoftBody library and its headers based on the INSTALL_LIBS flag and specific platform conditions.

```cmake
IF (INSTALL_LIBS)
	IF (NOT INTERNAL_CREATE_DISTRIBUTABLE_MSVC_PROJECTFILES)
		IF (${CMAKE_MAJOR_VERSION}.${CMAKE_MINOR_VERSION} GREATER 2.5)
			IF (APPLE AND BUILD_SHARED_LIBS AND FRAMEWORK)
				INSTALL(TARGETS BulletSoftBody DESTINATION .)
			ELSE (APPLE AND BUILD_SHARED_LIBS AND FRAMEWORK)
			INSTALL(TARGETS BulletSoftBody DESTINATION lib${LIB_SUFFIX})
				INSTALL(DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR}
DESTINATION ${INCLUDE_INSTALL_DIR} FILES_MATCHING PATTERN "*.h"  PATTERN
".svn" EXCLUDE PATTERN "CMakeFiles" EXCLUDE)
			ENDIF (APPLE AND BUILD_SHARED_LIBS AND FRAMEWORK)
		ENDIF (${CMAKE_MAJOR_VERSION}.${CMAKE_MINOR_VERSION} GREATER 2.5)

		IF (APPLE AND BUILD_SHARED_LIBS AND FRAMEWORK)
			SET_TARGET_PROPERTIES(BulletSoftBody PROPERTIES FRAMEWORK true)
			SET_TARGET_PROPERTIES(BulletSoftBody PROPERTIES PUBLIC_HEADER "${BulletSoftBody_HDRS}")
		ENDIF (APPLE AND BUILD_SHARED_LIBS AND FRAMEWORK)
	ENDIF (NOT INTERNAL_CREATE_DISTRIBUTABLE_MSVC_PROJECTFILES)
ENDIF (INSTALL_LIBS)
```

--------------------------------

### Lua Table Constructor Example

Source: https://github.com/emscripten-core/emscripten/blob/main/test/third_party/lua/doc/manual.html

Demonstrates the creation and initialization of a Lua table using various field syntaxes. Fields with explicit keys, named fields, and sequential fields are shown.

```lua
a = { [f(1)] = g; "x", "y"; x = 1, f(x), [30] = 23; 45 }
```

--------------------------------

### Install a specific Emscripten SDK version

Source: https://github.com/emscripten-core/emscripten/blob/main/site/source/docs/getting_started/downloads.md

Install a specific tagged version of the Emscripten SDK by providing the version number.

```bash
./emsdk install 1.38.45
```

--------------------------------

### Install OpenJPEG Library

Source: https://github.com/emscripten-core/emscripten/blob/main/test/third_party/openjpeg/libopenjpeg/CMakeLists.txt

Installs the built OpenJPEG library to the specified destination directory. This ensures the library is available for linking by other projects.

```cmake
INSTALL(TARGETS ${OPENJPEG_LIBRARY_NAME}
  EXPORT OpenJPEGTargets
  DESTINATION ${OPENJPEG_INSTALL_LIB_DIR} COMPONENT Libraries
)
```

--------------------------------

### Enable CPU Demos

Source: https://github.com/emscripten-core/emscripten/blob/main/test/third_party/bullet/CMakeLists.txt

Enables the building of original Bullet CPU demos.

```cmake
OPTION(BUILD_CPU_DEMOS "Build original Bullet CPU demos"        ON)
```

--------------------------------

### Show Test Suite Help

Source: https://github.com/emscripten-core/emscripten/blob/main/site/source/docs/getting_started/test-suite.md

Run the test suite runner with the --help flag to view available options and commands.

```bash
test/runner --help
```

--------------------------------

### Mounting NODEFS in Node.js

Source: https://github.com/emscripten-core/emscripten/blob/main/site/source/docs/api_reference/Filesystem-API.md

Example demonstrating how to mount a directory using NODEFS within a Node.js environment. This maps host filesystem directories to Emscripten's virtual filesystem.

```c
/*
 * See [this test](https://github.com/emscripten-core/emscripten/blob/main/test/fs/test_nodefs_rw.c)
 * for an example.
 */
```

--------------------------------

### Initialize ALUT with Command-Line Arguments

Source: https://github.com/emscripten-core/emscripten/blob/main/test/third_party/freealut/doc/alut.html

Pass argc and argv from main to alutInit to allow ALUT to process its own command-line options. Recognized options are consumed.

```c
int
main (int argc, char **argv)
{
  alutInit (&argc, argv);
  ...
}
```

--------------------------------

### Serve HTML Page with Local Server

Source: https://context7.com/emscripten-core/emscripten/llms.txt

Compile a C file with the `--emrun` flag and then use `emrun` to serve the generated HTML page locally.

```bash
emcc --emrun hello.c -o hello.html
```

```bash
emrun hello.html
```

--------------------------------

### Install Sphinx Dependencies

Source: https://github.com/emscripten-core/emscripten/blob/main/docs/process.md

Installs the necessary Sphinx version for developing the emscripten.org website. You may need to add ~/.local/bin to your PATH.

```bash
pip3 install -r requirements-dev.txt
```

--------------------------------

### sys/uio.h Entrypoints

Source: https://github.com/emscripten-core/emscripten/blob/main/system/lib/llvm-libc/config/linux/aarch64/entrypoints.txt

Entrypoints for functions related to scatter/gather I/O.

```APIDOC
## writev

### Description
Write data from multiple buffers to a file descriptor.

### Method
N/A (C function)

### Endpoint
N/A

## readv

### Description
Read data into multiple buffers from a file descriptor.

### Method
N/A (C function)

### Endpoint
N/A
```

--------------------------------

### alutCreateBufferHelloWorld

Source: https://github.com/emscripten-core/emscripten/blob/main/test/third_party/freealut/doc/alut.html

Creates an OpenAL buffer containing a 'Hello, world!' sound. This function is useful for quick testing or simple audio playback scenarios.

```APIDOC
## alutCreateBufferHelloWorld

### Description
Creates an OpenAL buffer containing the sound of someone saying 'Hello, world!'.

### Synopsis
ALuint alutCreateBufferHelloWorld (void);

### Return Value
On success, returns a handle to an OpenAL buffer. Returns AL_NONE on failure.

### Errors
- ALUT_ERROR_OUT_OF_MEMORY
- ALUT_ERROR_INVALID_OPERATION
- ALUT_ERROR_NO_CURRENT_CONTEXT
- ALUT_ERROR_AL_ERROR_ON_ENTRY
- ALUT_ERROR_ALC_ERROR_ON_ENTRY
- ALUT_ERROR_GEN_BUFFERS
- ALUT_ERROR_BUFFER_DATA
```