General :: System Call To Know Files And Directories In PWD

I am searching for any system call similar to "ls" command we use in shell. My requirement is knowing the files and directories in curent working directory and process them based on there type. Here as of now I spawn another procees with system command like system
("sh ls -l | grep ^d | awk '{print $9}'").

Instead of this I want to use any system command where I can capture this information directly into my local character buffer. My opinion is that system calls will not spawn another process as a result less time it takes, another reason is once I use the system command again I need to capture the information to a local file then again read it into local buffer. I want to avoid the file manipulation here.