The sigrok project aims at creating a portable, cross-platform,
Free/Libre/Open-Source signal analysis software suite that supports
various device types, such as logic analyzers, MSOs, oscilloscopes,
multimeters, LCR meters, sound level meters, thermometers,
hygrometers, anemometers, light meters, DAQs, dataloggers,
function generators, spectrum analyzers, power supplies,
GPIB interfaces, and more.

sigrok-cli is a command-line tool written in C, which uses both libsigrok
and libsigrokdecode to provide the basic sigrok functionality from the
command-line. Among other things, it's useful for scripting purposes.