This is a small demo command line C program for Z39.50 queries using Index Data's yaz Z39.50 C toolkit:
https://github.com/indexdata/yaz
This z39-demo program was written by Cyrus Gomes, UA Libraries Data and Informatics Student Assistant. Please note that this software is an experiment program written for demo and teaching purposes. It's not been thoroughly tested for bugs. For more information about how to compile and run the z30-demo program, see The University of Alabama Libraries Scholarly API Cookbook Z39.50 page:
https://ualibweb.github.io/UALIB_ScholarlyAPI_Cookbook/content/scripts/shell/shell_z3950.html