Question

i did these steps and make shared library.
but here i have some questions

1. i want know why we write 4 and 5 steps.

   i know only that these steps is used for link library

2. in 6th step why we use only lhuffman insted of libhuffman

steps:

1 gcc -c -fPIC filebits.c -o filebits.o
2 gcc -shared -Wl,-soname,libhuff.so.1 -o libhuffman.so.1.0.1 filebits.o
3 mv libhuffman.so.1.0.1 /home/mydesktop/slib/
4 ln -sf /home/mydesktop/slib/libhuffman.so.1.0.1  /home/mydesktop/slib/libhuffman.so
5 ln -sf /home/mydesktop/slib/libhuffman.so.1.0.1  /home/mydesktop/slib/libhuffman.so.1
6 gcc -o app app.c -lhuffman
7 ./app

please explain me these steps

Answer 1

 1. i want know why we write 4 and 5 steps.

In step 4 you are creating a soft link to the library name which is looked up by the linker to link.
In step 5 you are creating a soft link to the library indicating its major version. There is no need for you to follow these steps as such instead you can generate libhuffman.so as the output in the first step which is what the linker looks up for. But this convention is followed so that library’s major & minor versions are tracked easily. Generally, library has the name as library_name.MAJOR_VERSION.MINOR_VERSION. There is soft link to that in the form of library_name.MAJOR_VERSION & another soft link with just library_name. library_name is in the form of lib[library_name].so as that is format expected by the linker when using -l option. You can check libraries on your Linux PC you will see this convention being followed in a lot of cases. This link provides some details regarding this.

2.in 6th step why we use only lhuffman insted of libhuffman

GCC linker adds lib & .a (or .so) to the library name which is specified with -l option.
Hope this helps!