@spec cat(Path.t()) :: :"do not show this result in output"

Reads and prints out the contents of a file

@spec cmd(String.t() | charlist()) :: integer()

Run a command and return the exit code. This function is intended to be run interactively.

@spec date() :: String.t()

Return the date and time in UTC

@spec dmesg() :: :"do not show this result in output"

Print out kernel log messages

@spec exit() :: true

Exit the current IEx session

@spec fw_validate() :: :ok | {:error, String.t()}

Validate a firmware image

All official Nerves Systems automatically validate newly installed firmware. For some systems, it's possible to disable this so that new firmware gets one chance to boot. If it's not "validated" before a reboot, then the device reverts to the old firmware.

@spec geo(keyword()) :: :"do not show this result in output"

Geo-locate this Elixir instance

Options:

• :ifname - Network interface to use (e.g., "eth0")
• :whenwhere_url - URL for the whenwhere server to query. Defaults to http://whenwhere.nerves-project.org

@spec grep(Regex.t(), Path.t()) :: :"do not show this result in output"

Run a regular expression on a file and print the matching lines.

iex> grep ~r/video/, "/etc/mime.types"

If colored is enabled for the shell, the matches will be highlighted red.

@spec hex(integer()) :: String.t()

Inspect a value with all integers printed out in hex. This is useful for one-off hex conversions. If you're doing a lot of work that requires hexadecimal output, you should consider running:

IEx.configure(inspect: [base: :hex])

The drawback of doing the above is that strings print out as hex binaries.

@spec history(pid()) :: :"do not show this result in output"

Print out the IEx shell history

The default is to print the history from the current group leader, but any group leader can be passed in if desired.

@spec hostname() :: String.t()

Return the hostname

Examples

iex> hostname
"nerves-1234"

@spec httpget(String.t(), dest: Path.t(), verbose: boolean()) ::
  :"do not show this result in output"

Perform a HTTP GET request for the specified URL

By default, the results are printed or you can optionally choose to download it to a specific location on the file system.

Options:

• :dest - File path to write the response to. Defaults to printing to the terminal.
• :ifname - Network interface to use (e.g., "eth0")
• :timeout - Download timeout. Defaults to 30_000 ms
• :verbose - Display request and response headers. Disabled by default.

@spec ifconfig() :: :"do not show this result in output"

Print out the network interfaces and their addresses.

@spec inspect_bits(number() | binary()) :: :"do not show this result in output"

Pretty prints a number in hex, octal and binary

Example:

iex> Toolshed.inspect_bits(123)
Decimal     : 123
Hexadecimal : 0000_007B
Octal       : 173
Binary      : 01111011

@spec load_term!(Path.t()) :: term()

Load an Erlang term from the filesystem.

Examples

iex> save_term!({:some_interesting_atom, ["some", "list"]}, "/root/some_atom.term")
{:some_interesting_atom, ["some", "list"]}
iex> load_term!("/root/some_atom.term")
{:some_interesting_atom, ["some", "list"]}

@spec log_attach(keyword()) :: :ok

Attach the current session to the Elixir logger

This forwards incoming log messages to the terminal. Call log_detach/0 to stop the messages.

Behind the scenes, this uses Erlang's logger_std_h and Elixir's log formatter. Options include all of the ones from Logger.Formatter and the ability to set the level.

For ease of use, here are the common options:

• :level - the minimum log level to report. E.g., specify level: :warning to only see warnings and errors.
• :metadata - a list of metadata keys to show or :all

@spec log_detach() :: :ok | {:error, :not_attached}

Detach the current session from the Elixir logger

@spec lsmod() :: :"do not show this result in output"

Print out the loaded kernel modules

Aside from printing out whether the kernel has been tainted, the Linux utility of the same name just dump the contents of "/proc/modules" like this one.

Some kernel modules may be built-in to the kernel image. To see those, run cat "/lib/modules/x.y.z/modules.builtin" where x.y.z is the kernel's version number.

@spec lsof() :: :ok

List out open files by process

This is an simple version of lsof that works on Linux and Nerves. While running the normal version of lsof provides more information, this can be convenient when lsof isn't easily available or can't be run due to :emfile errors from starting port processes due to too many files being open..

@spec lsusb() :: :"do not show this result in output"

Print out information on all of the connected USB devices.

@spec multicast_addresses() :: :ok

List all active multicast addresses

This lists out multicast addresses by network interface similar to ip maddr show. It currently only works on Linux.

@spec nslookup(String.t()) :: :"do not show this result in output"

Lookup the specified hostname in the DNS and print out the addresses.

Examples

iex> nslookup "google.com"
Name:     google.com
Address:  172.217.7.238
Address:  2607:f8b0:4004:804::200e

@spec ping(
  String.t(),
  keyword()
) :: :"do not show this result in output"

Ping an IP address using ICMP.

NOTE: Specifying an :ifname only sets the source IP address for the connection. This is only a hint to use the specified interface and not a guarantee. For example, if you have two interfaces on the same LAN, the OS routing tables may send traffic out one interface in preference to the one that you want. On Linux, you can enable policy-based routing and add source routes to guarantee that packets go out the desired interface.

Options:

• :count - number of pings to send (defaults to 3)
• :identifier - the identifier to use in the ICMP packets (default is to generate one)
• :ifname - network interface to use (e.g., "eth0")
• :timeout - time in seconds to wait for a host to respond (defaults to 10 seconds)

Examples

iex> ping "nerves-project.org"
Response from nerves-project.org (185.199.108.153): icmp_seq=0 time=14.908ms
Response from nerves-project.org (185.199.108.153): icmp_seq=1 time=9.057ms
Response from nerves-project.org (185.199.108.153): icmp_seq=2 time=21.099ms

iex> ping "google.com", ifname: "wlp5s0"
Response from google.com (172.217.7.206): icmp_seq=0 time=88.602ms

@spec poweroff() :: no_return()

Helper for gracefully powering off

Not all Nerves devices support powering themselves off. These devices reboot instead.

@spec qr_encode(String.t()) :: :"do not show this result in output"

Generate an ASCII art QR code

See https://github.com/chubin/qrenco.de for more information.

@spec reboot() :: no_return()

Shortcut to reboot a board. This is a graceful reboot, so it takes some time before the real reboot.

@spec reboot!() :: no_return()

Reboot immediately without a graceful shutdown. This is for the impatient.

@spec save_term!(term(), Path.t()) :: term()

Save an Erlang term to the filesystem for easy loading later

This function returns the value passed in to allow easy piping.

Examples

iex> :sys.get_state(MyServer) |> save_term!("/root/my_server.term")
# Reboot board
iex> :sys.replace_state(&load_term!("/root/my_server.term"))

@spec save_value(any(), Path.t(), keyword()) :: :ok | {:error, File.posix()}

Save a value to a file as Elixir terms

Examples

# Save the contents of SystemRegistry to a file
iex> SystemRegistry.match(:_) |> save_value("/root/sr.txt")
:ok

@spec speed_test(speed_test_options()) :: :ok

Perform a download speed test

Calling this with no options measures the download speed of a small test file. The test file may not be large enough or close enough to you to produce a good measurement. To fix this, pass a :url to a better file. To change the default, add the following to your application environment:

config :toolshed, speed_test_url: "http://my_company.com/speed_test_file.bin"

Commercial users are encouraged to specify their own files to minimize our bandwidth costs.

Please be aware that this function is somewhat simplistic in how it measures download performance.

Options:

• :duration - Maximum duration in milliseconds (defaults to 5 seconds)
• :ifname - Interface to use (e.g., "wwan0" or "eth0")
• :url - File to download for the test

@spec tcping(
  String.t(),
  keyword()
) :: :"do not show this result in output"

Ping an IP address using TCP

This tries to connect to the remote host using TCP instead of sending an ICMP echo request like normal ping. This sometimes works better than ping if the remote server or any machine in between drops ICMP messages.

Options:

• :count - number of pings to send (defaults to 3)
• :ifname - Specify a network interface to use. (e.g., "eth0")
• :port - Which TCP port to try (defaults to 80)

Examples

iex> tcping "nerves-project.org"
Response from nerves-project.org (185.199.108.153:80): time=4.155ms
Response from nerves-project.org (185.199.108.153:80): time=10.385ms
Response from nerves-project.org (185.199.108.153:80): time=12.458ms

iex> tcping "google.com", ifname: "wlp5s0"
Response from google.com (172.217.7.206:80): time=88.602ms

@spec top(keyword()) :: :"do not show this result in output"

Interactively show the top Elixir processes

This is intended to be called from the IEx prompt and will periodically update the console with the top processes. Press enter to exit.

Options:

• :order - the sort order for the results (:reductions, :delta_reductions, :mailbox, :delta_mailbox, :total_heap_size, :delta_total_heap_size, :heap_size, :delta_heap_size, :stack_size, :delta_stack_size)

@spec tree(Path.t()) :: :"do not show this result in output"

Print out directories and files in tree form.

@spec uname() :: :"do not show this result in output"

Print out information about the running software

This is similar to the Linux uname to help people remember what to type.

@spec uptime() :: :"do not show this result in output"

Print out the current uptime.

@spec weather() :: :"do not show this result in output"

Display the local weather

See http://wttr.in/:help for more information.