Question

How to create a .so and .a file in UNIX. Do we have any standard utility for it?

Answer 1

*.a – archive library
to create it compile your sources:

gcc -c -o foo.o foo.c
gcc -c -o boo.o boo.c

ar -rsc yourlib.a foo.o boo.o

so – position independent code shared library

gcc -fPIC -shared  -soname,libfoo.so.1 -o libfoo.so.1.0 foo.c boo.c