Module wasi_snapshot_preview1

Functions

args_get^⚠

Read command-line argument data. The size of the array should match that returned by args_sizes_get. Each argument is expected to be \0 terminated.

args_sizes_get^⚠

Return command-line argument data sizes.

clock_res_get^⚠

Return the resolution of a clock. Implementations are required to provide a non-zero value for supported clocks. For unsupported clocks, return errno::inval. Note: This is similar to clock_getres in POSIX.

clock_time_get^⚠

Return the time value of a clock. Note: This is similar to clock_gettime in POSIX.

environ_get^⚠

Read environment variable data. The sizes of the buffers should match that returned by environ_sizes_get. Key/value pairs are expected to be joined with =s, and terminated with \0s.

environ_sizes_get^⚠

Return environment variable data sizes.

fd_advise^⚠

Provide file advisory information on a file descriptor. Note: This is similar to posix_fadvise in POSIX.

fd_allocate^⚠

Force the allocation of space in a file. Note: This is similar to posix_fallocate in POSIX.

fd_close^⚠

Close a file descriptor. Note: This is similar to close in POSIX.

fd_datasync^⚠

Synchronize the data of a file to disk. Note: This is similar to fdatasync in POSIX.

fd_fdstat_get^⚠

Get the attributes of a file descriptor. Note: This returns similar flags to fsync(fd, F_GETFL) in POSIX, as well as additional fields.

fd_fdstat_set_flags^⚠

Adjust the flags associated with a file descriptor. Note: This is similar to fcntl(fd, F_SETFL, flags) in POSIX.

fd_fdstat_set_rights^⚠

Adjust the rights associated with a file descriptor. This can only be used to remove rights, and returns errno::notcapable if called in a way that would attempt to add rights

fd_filestat_get^⚠

Return the attributes of an open file.

fd_filestat_set_size^⚠

Adjust the size of an open file. If this increases the file’s size, the extra bytes are filled with zeros. Note: This is similar to ftruncate in POSIX.

fd_filestat_set_times^⚠

Adjust the timestamps of an open file or directory. Note: This is similar to futimens in POSIX.

fd_pread^⚠

Read from a file descriptor, without using and updating the file descriptor’s offset. Note: This is similar to preadv in POSIX.

fd_prestat_dir_name^⚠

Return a description of the given preopened file descriptor.

fd_prestat_get^⚠

Return a description of the given preopened file descriptor.

fd_pwrite^⚠

Write to a file descriptor, without using and updating the file descriptor’s offset. Note: This is similar to pwritev in POSIX.

fd_read^⚠

Read from a file descriptor. Note: This is similar to readv in POSIX.

fd_readdir^⚠

Read directory entries from a directory. When successful, the contents of the output buffer consist of a sequence of directory entries. Each directory entry consists of a dirent object, followed by dirent::d_namlen bytes holding the name of the directory entry. This function fills the output buffer as much as possible, potentially truncating the last directory entry. This allows the caller to grow its read buffer size in case it’s too small to fit a single large directory entry, or skip the oversized directory entry.

fd_renumber^⚠

Atomically replace a file descriptor by renumbering another file descriptor. Due to the strong focus on thread safety, this environment does not provide a mechanism to duplicate or renumber a file descriptor to an arbitrary number, like dup2(). This would be prone to race conditions, as an actual file descriptor with the same number could be allocated by a different thread at the same time. This function provides a way to atomically renumber file descriptors, which would disappear if dup2() were to be removed entirely.

fd_seek^⚠

Move the offset of a file descriptor. Note: This is similar to lseek in POSIX.

fd_sync^⚠

Synchronize the data and metadata of a file to disk. Note: This is similar to fsync in POSIX.

fd_tell^⚠

Return the current offset of a file descriptor. Note: This is similar to lseek(fd, 0, SEEK_CUR) in POSIX.

fd_write^⚠

Write to a file descriptor. Note: This is similar to writev in POSIX.

path_create_directory^⚠

Create a directory. Note: This is similar to mkdirat in POSIX.

path_filestat_get^⚠

Return the attributes of a file or directory. Note: This is similar to stat in POSIX.

path_filestat_set_times^⚠

Adjust the timestamps of a file or directory. Note: This is similar to utimensat in POSIX.

path_link^⚠

Create a hard link. Note: This is similar to linkat in POSIX.

path_open^⚠

Open a file or directory. The returned file descriptor is not guaranteed to be the lowest-numbered file descriptor not currently open; it is randomized to prevent applications from depending on making assumptions about indexes, since this is error-prone in multi-threaded contexts. The returned file descriptor is guaranteed to be less than 2**31. Note: This is similar to openat in POSIX.

path_readlink^⚠

Read the contents of a symbolic link. Note: This is similar to readlinkat in POSIX.

path_remove_directory^⚠

Remove a directory. Return errno::notempty if the directory is not empty. Note: This is similar to unlinkat(fd, path, AT_REMOVEDIR) in POSIX.

path_rename^⚠

Rename a file or directory. Note: This is similar to renameat in POSIX.

path_symlink^⚠

Create a symbolic link. Note: This is similar to symlinkat in POSIX.

path_unlink_file^⚠

Unlink a file. Return errno::isdir if the path refers to a directory. Note: This is similar to unlinkat(fd, path, 0) in POSIX.

poll_oneoff^⚠

Concurrently poll for the occurrence of a set of events.

proc_exit^⚠

Terminate the process normally. An exit code of 0 indicates successful termination of the program. The meanings of other values is dependent on the environment.

proc_raise^⚠

Send a signal to the process of the calling thread. Note: This is similar to raise in POSIX.

random_get^⚠

Write high-quality random data into a buffer. This function blocks when the implementation is unable to immediately provide sufficient high-quality random data. This function may execute slowly, so when large mounts of random data are required, it’s advisable to use this function to seed a pseudo-random number generator, rather than to provide the random data directly.

sched_yield^⚠

Temporarily yield execution of the calling thread. Note: This is similar to sched_yield in POSIX.

sock_accept^⚠

Accept a new incoming connection. Note: This is similar to accept in POSIX.

sock_recv^⚠

Receive a message from a socket. Note: This is similar to recv in POSIX, though it also supports reading the data into multiple buffers in the manner of readv.

sock_send^⚠

Send a message on a socket. Note: This is similar to send in POSIX, though it also supports writing the data from multiple buffers in the manner of writev.

sock_shutdown^⚠

Shut down socket send and receive channels. Note: This is similar to shutdown in POSIX.