C-language stat function

C-language stat functionStat

#include <sys/stat.h> #include <unistd.h>
function prototype: int stat (const char * file_name, struct stat * buf)
* * Function Description: **stat function get file_name points to the file status of the file and saves the file information to the struct buf , execution successfully returns 0, failure returns-1, The error code is stored in errno
struct struct STAT parameter description:

struct stat{dev_t st_dev;//device file's device number ino_t St_ino;//inode file's index node mode_t st_mode; type of//protection file and access rights limited to nlink_t St_nlink;    Number of hard links connects to the file with a file value of 1 that has just been created. uid_t St_uid; User ID of the owner of the owners file gid_t st_gid; Group ID of the owner of the file owners of the groups identification code dev_t St_rdev; Device type If this file is an appliance device file, its equipment number off_t st_size; Total size, in bytes file size, calculated in bytes unsigned long st_blksize;    BlockSize the I/O buffer size for the filesystem I/O file system. unsigned long st_blocks;    Number of blocks allocated occupies a chunk of files, each chunk size is 512 bytes. time_t St_atime;    Time of lastaccess file was last accessed or executed, and generally only changed with Mknod, Utime, read, write, and Tructate. time_t St_mtime; Time of last modification file was modified at the end of the day, generally only in Mknod, Utime and write will change time_t st_ctime; Time of last changes i-node the most recent change, this parameter is updated when the file owner, group, and permissions are changed};

St_mode Description:

1, s_ifmt0170000Bit masks for file types2, S_ifsock0140000Scoket3, S_iflnk0120000Symbolic connection4, S_ifreg0100000General documents5, s_ifblk0060000Block device6, S_ifdir0040000Directory7, S_IFCHR0020000Character device8, S_ififo0010000Advanced First Out9, S_isuid04000File (set User-id on execution) bitTen, S_isgid02000File (set Group-id on execution) bit One, S_ISVTX01000Sticky bits of the file A, S_irusr (S_iread)00400File owners have Read permissions -, S_iwusr (S_iwrite)00200File owner with writable permission -, S_ixusr (s_iexec)00100File owner has executable permissions the, S_IRGRP00040User groups with readable permissions -, S_IWGRP00020User groups have writable permissions -, S_IXGRP00010User groups with executable permissions -, S_iroth00004Other users have Read permissions +, S_iwoth00002Other users have writable permissions -, S_ixoth00001Other users with executable permissions The above file types are defined in POSIX to check these types of macro definitions +, S_islnk (St_mode) to determine if it is a symbolic connection A, S_isreg (St_mode) is a generic file at, S_isdir (St_mode) is a directory -, S_ISCHR (St_mode) is a character device file -, S_isblk (s3e) is FIFO -, S_issock (St_mode) is a socket if a directory has a sticky bit (s_isvtx), then the file in this directory can only be deleted or renamed by the file owner, this directory owner, or root.

C-language stat function