fstat, stat, _wstat

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Header File

sys\stat.h

Category

Input/output Routines

Prototype

int fstat(int handle, struct stat *statbuf);

int stat(const char *path, struct stat *statbuf);

int _wstat(const wchar_t *path, struct _stat *statbuf);

Description

Gets open file information.

fstat stores information in the stat structure about the file or directory associated with handle.

stat stores information about a given file or directory in the stat/_stat structure. The name of the file is path.

statbuf points to the stat/_stat structure (defined in sys\stat.h). That structure contains the following fields:

st_mode	Bit mask giving information about the file's mode
st_dev	Drive number of disk containing the file or file handle if the file is on a device
st_rdev	Same as st_dev
st_nlink	Set to the integer constant 1
st_size	Size of the file in bytes
st_atime	Most recent access (Windows) or last time modified (DOS)
st_mtime	Same as st_atime
st_ctime	Same as st_atime

The stat structure contains three more fields not mentioned here. They contain values that are meaningful only in UNIX.

The st_mode bit mask that gives information about the mode of the open file includes the following bits:

One of the following bits will be set:

S_IFCHR	If handle refers to a device.
S_IFREG	If an ordinary file is referred to by handle.

One or both of the following bits will be set:

S_IWRITE	If user has permission to write to file.
S_IREAD	If user has permission to read to file.

The HPFS and NTFS file-management systems make the following distinctions:

st_atime	Most recent access
st_mtime	Most recent modify
st_ctime	Creation time

Return Value

fstat and stat return 0 if they successfully retrieved the information about the open file.

On error (failure to get the information) these functions return -1 and set the global variable errno to

EBADF

Bad file handle

Example

 #include <sys\stat.h>
 #include <stdio.h>
 #include <time.h>
 int main(void)
 {
    struct stat statbuf;
    FILE *stream;
    /* open a file for update */
    if ((stream = fopen("DUMMY.FIL", "w+"))
        == NULL)
    {
       fprintf(stderr, "Cannot open output file.\n");
       return(1);
    }
    fprintf(stream, "This is a test");
    fflush(stream);
    /* get information about the file */
    fstat(fileno(stream), &statbuf);
    fclose(stream);
    /* display the information returned */
    if (statbuf.st_mode & S_IFCHR)
       printf("Handle refers to a device.\n");
    if (statbuf.st_mode & S_IFREG)
       printf("Handle refers to an ordinary file.\n");
    if (statbuf.st_mode & S_IREAD)
       printf("User has read permission on file.\n");
    if (statbuf.st_mode & S_IWRITE)
       printf("User has write permission on file.\n");
    printf("Drive letter of file: %c\n", 'A'+statbuf.st_dev);
    printf("Size of file in bytes: %ld\n", statbuf.st_size);
    printf("Time file last opened: %s\n", ctime(&statbuf.st_ctime));
    return 0;
 }