I have little knowledge about ipv6 address. All I know is that it is longer than ipv4 address thus can be assigned to more hosts in the world. ipv6 addresses […]

The idea behind dkim is simple. You add a “DKIM-Signature:” in your email message. The stmp server receiving the email checks the header, pulls the dns record of the domain, […]

sha256 is an algorithm to map a string of any length to a 256bit string(so called hash). The input of the algorithm is a string of any length but the […]

When compiling, gcc may output many error messages which are dazzling. Although you can locate the error in the source code in the end, you may never notice the details […]

I have a big misunderstanding about make. I thought if I run “make” or “make -f Makefile”, make will check the first target in the makefile and possibly update targets […]

How to build a shared library using gcc/g++? Building a shared library with gcc is easy but it takes 2 steps: gcc -c -fpic mytools.c gcc -shared -o libmytools.so mytools.o […]