#include "wasm.h"
#include <stdint.h>
#include <wasmtime/conf.h>

Typedefs
typedef struct wasi_config_t	wasi_config_t
	Convenience alias for wasi_config_t.

typedef size_t	wasi_dir_perms
	The permissions granted for directories when preopening them, which is a bitmask with flag values from wasi_dir_perms_flags.

typedef size_t	wasi_file_perms
	The max permissions granted a file within a preopened directory, which is a bitmask with flag values from wasi_file_perms_flags.

Enumerations
enum	wasi_dir_perms_flags { WASMTIME_WASI_DIR_PERMS_READ = 1 , WASMTIME_WASI_DIR_PERMS_WRITE = 2 }
	The permissions granted for a directory when preopening it. More...

enum	wasi_file_perms_flags { WASMTIME_WASI_FILE_PERMS_READ = 1 , WASMTIME_WASI_FILE_PERMS_WRITE = 2 }
	The permissions granted for files when preopening a directory. More...

Functions
void	wasi_config_delete (wasi_config_t *)
	Deletes a configuration object.

wasi_config_t *	wasi_config_new ()
	Creates a new empty configuration object. More...

bool	wasi_config_set_argv (wasi_config_t config, size_t argc, const char argv[])
	Sets the argv list for this configuration object. More...

void	wasi_config_inherit_argv (wasi_config_t *config)
	Indicates that the argv list should be inherited from this process's argv list.

bool	wasi_config_set_env (wasi_config_t config, size_t envc, const char names[], const char *values[])
	Sets the list of environment variables available to the WASI instance. More...

void	wasi_config_inherit_env (wasi_config_t *config)
	Indicates that the entire environment of the calling process should be inherited by this WASI configuration.

bool	wasi_config_set_stdin_file (wasi_config_t config, const char path)
	Configures standard input to be taken from the specified file. More...

void	wasi_config_set_stdin_bytes (wasi_config_t config, wasm_byte_vec_t binary)
	Configures standard input to be taken from the specified wasm_byte_vec_t. More...

void	wasi_config_inherit_stdin (wasi_config_t *config)
	Configures this process's own stdin stream to be used as stdin for this WASI configuration.

bool	wasi_config_set_stdout_file (wasi_config_t config, const char path)
	Configures standard output to be written to the specified file. More...

void	wasi_config_inherit_stdout (wasi_config_t *config)
	Configures this process's own stdout stream to be used as stdout for this WASI configuration.

bool	wasi_config_set_stderr_file (wasi_config_t config, const char path)
	Configures standard output to be written to the specified file. More...

void	wasi_config_inherit_stderr (wasi_config_t *config)
	Configures this process's own stderr stream to be used as stderr for this WASI configuration.

bool	wasi_config_preopen_dir (wasi_config_t config, const char host_path, const char *guest_path, wasi_dir_perms dir_perms, wasi_file_perms file_perms)
	Configures a "preopened directory" to be available to WASI APIs. More...

Detailed Description

C API for WASI

Enumeration Type Documentation

◆ wasi_dir_perms_flags

enum wasi_dir_perms_flags

The permissions granted for a directory when preopening it.

Enumerator
WASMTIME_WASI_DIR_PERMS_READ	This directory can be read, for example its entries can be iterated.
WASMTIME_WASI_DIR_PERMS_WRITE	This directory can be written to, for example new files can be created within it.

◆ wasi_file_perms_flags

enum wasi_file_perms_flags

The permissions granted for files when preopening a directory.

Enumerator
WASMTIME_WASI_FILE_PERMS_READ	Files can be read.
WASMTIME_WASI_FILE_PERMS_WRITE	Files can be written to.

Function Documentation

◆ wasi_config_new()

wasi_config_t * wasi_config_new ( )

Creates a new empty configuration object.

The caller is expected to deallocate the returned configuration

◆ wasi_config_preopen_dir()

bool wasi_config_preopen_dir	(	wasi_config_t *	config,
		const char *	host_path,
		const char *	guest_path,
		wasi_dir_perms	dir_perms,
		wasi_file_perms	file_perms
	)

Configures a "preopened directory" to be available to WASI APIs.

By default WASI programs do not have access to anything on the filesystem. This API can be used to grant WASI programs access to a directory on the filesystem, but only that directory (its whole contents but nothing above it).

The host_path argument here is a path name on the host filesystem, and guest_path is the name by which it will be known in wasm.

The dir_perms argument is the permissions that wasm will have to operate on guest_path. This can be used, for example, to provide readonly access to a directory. This argument is a bitmask with the following flag values:

WASMTIME_WASI_DIR_PERMS_READ
WASMTIME_WASI_DIR_PERMS_WRITE

The file_perms argument is similar to dir_perms but corresponds to the maximum set of permissions that can be used for any file in this directory. This argument is a bitmask with the following flag values:

WASMTIME_WASI_FILE_PERMS_READ
WASMTIME_WASI_FILE_PERMS_WRITE

◆ wasi_config_set_argv()

bool wasi_config_set_argv	(	wasi_config_t *	config,
		size_t	argc,
		const char *	argv[]
	)

Sets the argv list for this configuration object.

By default WASI programs have an empty argv list, but this can be used to explicitly specify what the argv list for the program is.

The arguments are copied into the config object as part of this function call, so the argv pointer only needs to stay alive for this function call.

This function returns true if all arguments were registered successfully, or false if an argument was not valid UTF-8.

◆ wasi_config_set_env()

bool wasi_config_set_env	(	wasi_config_t *	config,
		size_t	envc,
		const char *	names[],
		const char *	values[]
	)

Sets the list of environment variables available to the WASI instance.

By default WASI programs have a blank environment, but this can be used to define some environment variables for them.

It is required that the names and values lists both have envc entries.

The env vars are copied into the config object as part of this function call, so the names and values pointers only need to stay alive for this function call.

This function returns true if all environment variables were successfully registered. This returns false if environment variables are not valid UTF-8.

◆ wasi_config_set_stderr_file()

bool wasi_config_set_stderr_file	(	wasi_config_t *	config,
		const char *	path
	)

Configures standard output to be written to the specified file.

By default WASI programs have no stderr, but this configures the specified file to be used as stderr.

If the stderr location could not be opened for writing then false is returned. Otherwise true is returned.

◆ wasi_config_set_stdin_bytes()

void wasi_config_set_stdin_bytes	(	wasi_config_t *	config,
		wasm_byte_vec_t *	binary
	)

Configures standard input to be taken from the specified wasm_byte_vec_t.

By default WASI programs have no stdin, but this configures the specified bytes to be used as stdin for this configuration.

This function takes ownership of the binary argument.

◆ wasi_config_set_stdin_file()

bool wasi_config_set_stdin_file	(	wasi_config_t *	config,
		const char *	path
	)

Configures standard input to be taken from the specified file.

By default WASI programs have no stdin, but this configures the specified file to be used as stdin for this configuration.

If the stdin location does not exist or it cannot be opened for reading then false is returned. Otherwise true is returned.

◆ wasi_config_set_stdout_file()

bool wasi_config_set_stdout_file	(	wasi_config_t *	config,
		const char *	path
	)