Commend Line Interpreter

I need a short c++ code which do the following things in linux commend line. DO NOT use system() or execl(), execvp() except run comment **whereami** Display current working directory. **listall** Display a complete list of files and directories in current directory. **filelist** Display regular files in current directory. **dirlist** Display directories in current directory. **xlist** Display executable files in current directory. **run** Execute an external program such as ls, echo, firefox, etc. **chdir** Change the working directory of your program. **info** Display information such as name, type, size, permissions of a given file. **show** Display contents of a given file. **mode** Change permissions of a given file.