Advanced UNIX Programming

Scanning a Directory

While the family of routines (see directory(3)) starting with opendir(3) performs the functions that a programmer might need, they are somewhat tedious to code if you need them frequently enough. The scandir(3) and alphasort(3) routines assist in reducing the programmer effort required:

#include <sys/types.h>
#include <dirent.h>

int scandir(
    const char *dirname,
    struct dirent ***namelist,
    int (*select)(struct dirent *),
    int (*compar)(const void *, const void *));

int alphasort(const void *d1, const void *d2);

Function scandir(3) might look somewhat intimidating. However, once you spend a moment examining it, you will see that it is easy to use. The argument dirname is given the pathname of the directory that you want to ...