Expert: Narendra - 4/3/2005

Question
how will you create own library functions
in c language?
can you explain with example?

Answer
Suppose, you have 2 files send.c and get.c, which are part of your project.
Now, you want to create a library out of these, which will be named as libMyLibrary.so.
Herre are the steps to do that:

gcc -fPIC -c send.c
gcc -fPIC -c get.c
ld -shared -o libMyLibrary.so -lc send.o get.o

After executing these three statements, you will get libMyLibrary.so, which is a dynamic library.

Now, you want to use the functions defined in this library in your test program test.c
To compile that you can use the command:
gcc -L./ -o my_test test.c -lMyLibrary

The -L./ flag is to tell the linker to search for the library file in the current path also (along with standard path). The reason is that, your library is in current path.
If it is in a different path, then use it with -L flag.

Hope this helps.....

-ssnkumar