libsigrok is a shared library written in C, which provides the basic
hardware access drivers for logic analyzers and other supported
devices, as well as input/output file format support.

NOTE:
Slackware's libusb is too old. Thus, to enable more hardware support,
build with LIBUSB=yes ./libsigrok.SlackBuild

Optional, but highly recommended dependencies are (available from SlackBuilds.org):
libftdi, librevisa and libserialport.