Using the CLI

arrakis includes a command-line interface. It provides subcommands for all major operations.

Overview

arrakis [--url URL] [--ssh-proxy HOST] COMMAND [OPTIONS]

Global options:

Option	Description
--url, -u	Server URL (overrides ARRAKIS_SERVER)
--ssh-proxy HOST	Create an SSH tunnel to HOST for the connection
--version, -v	Print version and exit
--help, -h	Print help and exit

For detailed help on any command, run arrakis <command> --help.

Finding Channels

# find all channels matching a pattern
arrakis find "H1:LSC-.*"

# filter by data type and sample rate
arrakis find "H1:.*" --data-type float64 --min_rate 256 --max_rate 4096

# filter by publisher
arrakis find --publisher my_producer

Aliases: search, list

Counting Channels

arrakis count "H1:LSC-.*"

Accepts the same filter options as find.

Describing Channels

arrakis describe H1:CAL-DELTAL_EXTERNAL_DQ H1:LSC-POP_A_LF_OUT_DQ

Alias: show

You can read channel names from stdin:

echo "H1:CAL-DELTAL_EXTERNAL_DQ" | arrakis describe -

Streaming Data

# live stream
arrakis stream H1:CAL-DELTAL_EXTERNAL_DQ

# historical stream
arrakis stream H1:CAL-DELTAL_EXTERNAL_DQ --start 1187000000 --end 1187001000

# show latency information
arrakis stream H1:CAL-DELTAL_EXTERNAL_DQ --latency

The --start and --end options accept GPS times or arbitrary date/time strings.

Fetching Data

# fetch with explicit end time
arrakis fetch H1:CAL-DELTAL_EXTERNAL_DQ --start 1187000000 --end 1187001000

# fetch with duration
arrakis fetch H1:CAL-DELTAL_EXTERNAL_DQ --start 1187000000 --duration 1000

Either --end or --duration is required.

Publishing Data

# publish a sine wave to a channel
arrakis publish -p my_producer H1:FKE-TEST_CHANNEL1 "sin(t)"

# publish a constant value
arrakis publish -p my_producer H1:FKE-TEST_CHANNEL1 "42"

# list channels for a publisher
arrakis publish -p my_producer --list

Arguments are channel name + generator function pairs. Generator functions are sympy expressions where t represents time. Multiple pairs can be provided:

arrakis publish -p my_producer \
    H1:FKE-TEST_CHANNEL1 "sin(t)" \
    H1:FKE-TEST_CHANNEL2 "cos(t)"

Note

The publish subcommand requires the cli extra (pip install arrakis[cli]) which installs SymPy for expression parsing.

Output Formatting

Most subcommands default to table output. Alternative formats are available:

# default table output
arrakis find "H1:LSC-.*"

# JSON output
arrakis find "H1:LSC-.*" --json

# other formats (varies by formatter availability)
arrakis find "H1:LSC-.*" --repr

Use --table to explicitly request table formatting.