##### Shell Utilities

Requires v7.0.7.3+ -- ONLY Posix + ESP32

    cp ( "src" "dst" -- ) Copy "src" file to "dst".
    mv ( "src" "dst" -- ) Rename "src" file to "dst".
    rm ( "path" -- ) Remove "path" file.
    touch ( "path" -- ) Create "path" file if it doesn't exist.
    cat ( "path" -- ) Print contents of "path" file.
    ls ( "path" -- ) List files or directories in "path".

Requires v7.0.7.3+ -- ONLY Posix

    cd ( "path" -- ) Change director to "path".
    mkdir ( "path" -- ) Create directory "path".
    rmdir ( "path" -- ) Remove directory "path".
    pwd ( -- ) Print current directory.

##### Visual Editor

Requires v7.0.7.2+

    VISUAL EDIT ( "path" --) Enters a visual editor opening file "path".

    NOTE: On ESP32 requires connection over an ANSI serial terminal like Putty.

    LIMITATIONS: Terminal doesn't know screen dimensions
                 and is very redraw inefficient.

    Keys:
      Ctrl-S          -- Save now.
      Ctrl-X / Ctrl-Q -- Quit, asking Y/N to save.
      Ctrl-L          -- Redraw the screen.
      Backspace       -- Delete a character backwards.
      Arrow Keys      -- Movement.
      PgUp/PgDn       -- Scroll up/down a page.

##### Blocks

    USE ( "name" -- ) Use "name" as the blockfile, e.g. USE /spiffs/foo
    OPEN-BLOCKS ( a n -- ) Open a file as the block file
    LOAD ( n -- ) Evaluate a block
    THRU ( a b -- ) Load blocks a thru b
    LIST ( n -- ) List a block
    BLOCK ( n -- a ) Get a 1024 byte block
    BUFFER ( n -- a ) Get a 1024 byte block without regard to old contents
    UPDATE ( -- ) Mark the last block modified
    FLUSH ( -- ) Save and empty all buffers
    EMPTY-BUFFERS ( -- ) Empty all buffers
    SAVE-BUFFERS ( -- ) Save all buffers
    SCR ( -- a ) Pointer to last listed block

##### Block Editor

These words are available inside the `EDITOR` vocabulary. Note the block editor places newlines in the 63rd column of each line to make the block file readable in a text editor.

    WIPE ( -- ) Blank out the current block
    L ( -- ) List the current block
    D ( n -- ) Delete a line in the current block
    E ( n -- ) Clear a line in the current block
    R ( n "text" -- ) Replace a line in the current block
    A ( n "text" -- ) Add (insert) a line in the current block
    P ( -- ) Move to the previous block
    N ( -- ) Move to the next block

##### Sockets

Requires v7.0.7.2+ for UDP

These words are available inside the `sockets` vocabulary.

    socket ( domain type protocol -- sock/err )
    setsockopt ( sock level optname optval optlen -- 0/err )
    bind ( sock addr addrlen -- 0/err )
    listen ( sock connections -- 0/err )
    sockaccept ( sock addr addrlen -- sock/err ) -- varies from bsd socks
    connect ( sock addr addrlen -- 0/err )
    select ( numfds readfds writefds errfds timeout -- fd/err )
    poll ( pollfds n timeout -- fd/err )
    send ( sock a n flags -- n/err )
    sendto ( sock a n flags addr addrlen -- n/err )
    sendmsg ( sock msg flags -- n/err )
    recv ( sock a n flags -- n/err )
    recvfrom ( sock a n flags addr addrlen -- n/err )
    recvmsg ( sock msg flags -- n/err )
    gethostbyname ( hostnamez -- hostent/0 )
    errno ( -- err ) -- ESP32 only as of v7.0.7.2

    sockaddr ( "name" -- ) creates a sockaddr structure
    ->port@ ( a -- n ) get port from sockaddr
    ->port! ( n a -- ) set port in sockaddr
    ->addr@ ( a -- n ) get big-endian address from sockaddr
    ->addr! ( n a -- ) set big-endian address in sockaddr
    ip. ( n -- ) Print address as x.y.z.w IP address.

    ( Constants )
    SOCK_STREAM SOCK_DGRAM SOCK_RAW
    AF_INET
    sizeof(sockaddr_in)
    SOL_SOCKET
    SO_REUSEADDR

##### Dictionary Images and Startup

WARNING: Danger ahead.
Snapshotting the dictionary may not be stable across reinstallations of the C build of Forth.

A collection of non-standard words is provided that allow snapshotting the dictionary and restoring it at startup, with a start word.

    SAVE ( "name" -- ) Saves a snapshot of the current dictionary to a file.
    RESTORE ( "name" -- ) Restore a snapshot from a file.
    REMEMBER ( -- ) Save a snapshot to the default file
                    (./myforth or /spiffs/myforth on ESP32).
    STARTUP: ( "name" -- ) Save a snapshot to the default file arranging for
                           "name" to be run on startup.
    REVIVE ( -- ) Restore the default filename.
    RESET ( -- ) Delete the default filename.

Here's an example usage:

    : welcome ." Hello!" cr 100 0 do i . loop cr ;
    startup: welcome
    bye

    ( Next boot will run a custom startup message )

    reset

    ( Reset removes the custom message )

The `INTERNALS` vocabulary has some additional words for more control.

    SAVE-NAME ( a n -- ) Save a snapshot if the current vocabulary to a file.
    RESTORE-NAME ( a n -- ) Restore a snapshot from a file.
    'COLD ( -- a ) Address of the word that will be run on startup.
    REMEMBER-FILENAME ( -- a n ) Deferred word specifying the platform specific
                                 default snapshot filename.