lstat函数检查文件有关的信息

#include <unistd.h>
#include <stdio.h>
#include <stdlib.h>
#include <fcntl.h>
#include <pthread.h>

#include <sys/stat.h>
#include <time.h>

void PTS(time_t t)
{
    struct tm* _tm=localtime(&t);
    printf("%04d-%02d-%02d ",_tm->tm_year+1900,_tm->tm_mon+1,_tm->tm_mday);
    printf("%02d:%02d:%02d\n",_tm->tm_hour,_tm->tm_min,_tm->tm_sec);
}

int main(int argc,char* argv[])
{
    struct stat buf;

    if(argc!=2)
    {
        printf("usage %s filename\n",argv[0]);
        return 1;
    }

    if(access(argv[1],F_OK)!=0)
    {
        printf("'%s' doesn't exist,quit.\n",argv[1]);
        return 2;
    }
    if(lstat(argv[1],&buf)<0)
    {
        printf("function 'lstat' error.\n");
        return 3;
    }

    if(S_ISREG(buf.st_mode))
        printf("Regular.\n");

    if(S_ISDIR(buf.st_mode))
        printf("Directory.\n");

    if(S_ISCHR(buf.st_mode))
        printf("Character special.\n");

    if(S_ISBLK(buf.st_mode))
        printf("Block special.\n");

    if(S_ISFIFO(buf.st_mode))
        printf("FIFO.\n");

    if(S_ISLNK(buf.st_mode))
        printf("Symbolic link.\n");

    if(S_ISSOCK(buf.st_mode))
        printf("Socket.\n");
    ////////
    printf("i-node number: %ul\n",buf.st_ino);

    printf("device number: %ul\n",buf.st_dev);

    printf("number of links: %d\n",buf.st_nlink);

    printf("UID=%d, GID=%d\n",buf.st_uid,buf.st_gid);

    if(S_ISREG(buf.st_mode)||S_ISDIR(buf.st_mode)||S_ISLNK(buf.st_mode))
        printf("file size: %ld bytes\n",buf.st_size);
    printf("last access time: ");
    PTS(buf.st_atime);
    printf("last modify time: ");
    PTS(buf.st_mtime);
    printf("last file status change time: ");
    PTS(buf.st_ctime);

    return 0;
}