4.1.c

#include <stdio.h>
#include <stdlib.h>
#include <sys/stat.h>

int main(int argc, char **argv)
{
    int     i;
    struct stat buf;
    char    *ptr;

    for (i = 1; i < argc; i++) {
        printf("%s: ", *(argv + i));

        if (lstat(*(argv + i), &buf) < 0) {
            printf("lstat error\n");
            continue;
        }

        if (S_ISREG(buf.st_mode)) {
            ptr = "regular";
        } else if (S_ISDIR(buf.st_mode)) {
            ptr = "directory";
        } else if (S_ISCHR(buf.st_mode)) {
            ptr = "character special";
        } else if (S_ISBLK(buf.st_mode)) {
            ptr = "block special";
        } else if (S_ISFIFO(buf.st_mode)) {
            ptr = "pipo";
        } else if (S_ISLNK(buf.st_mode)) {
            ptr = "symbolic link";
        } else if (S_ISSOCK(buf.st_mode)) {
            ptr = "socket";
        } else {
            ptr = "** unknow mode **";
        }
        printf("%s\n", ptr);

    }

    return 0;
}