struct stat {mode_t st_mode;    /* file type & mode (permissions) */ino_t st_ino;            /* i-node number (serial number) */dev_t st_dev;          /* device number (file system) */dev_t st_rdev;         /* device number for specail files */nlink_t st_nlink;       /* number of links */uid_t st_uid;            /* user ID of owner */gid_t st_gid;            /* group ID of owner */off_t st_size;           /* size in bytes, for regular files */time_t st_atime;      /* time of last access */time_t st_mtime;      /* time of last modification */time_t st_ctime;       /* time of last file status change */blksize_t st_blksize; /* best I/O block size */blkcnt_t  st_blocks;  /* number of disk blocks allocate */
}

#include <stdlib.h>
#include <stdio.h>
#include <sys/stat.h>
#include <errno.h>
#include <string.h>
int
main(int argc, char *argv[])
{int i;struct stat buf;char *ptr;for (i=0; i < argc; i++) {printf("%s: ", argv[i]);if (lstat(argv[i], &buf) < 0) {printf("lstat error: %s\n", strerror(errno));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 = "fifo";} else if (S_ISLNK(buf.st_mode)) {ptr = "symbolic link";} else if (S_ISSOCK(buf.st_mode)) {ptr = "socket";} else {ptr = "** nuknown mode **";}printf("%s\n", ptr);}    exit(0);
}

lienhua34:demo$ gcc -o filetype filetype.c
lienhua34:demo$ ./filetype /etc/passwd /etc /dev/initctl /dev/log /dev/tty
./filetype: regular
/etc/passwd: regular
/etc: directory
/dev/initctl: lstat error: No such file or directory
/dev/log: socket
/dev/tty: character special