I want to use md5sum in my program. I found we can use md5sum in the command line in Linux, so do we can use the md5sum function call in the program. I want to find the md5sum source code in the Linux, but the one I found seems not the correct one. Does anybody know which file we need to include into the program in order to use the md5sum function, and which function we need to call, or where the source code about md5sum located? I found the coreutils md5sum.c in the linux and wanted to use it, but I don't know which file I need to include in the header of my program. Please help me, thanks.