Statbuf

Statbuf is a term used in some Unix-like systems to refer to a data structure that stores the results of a file status query. It is not a standardized term defined by POSIX, but rather an implementation-specific or historical name found in certain codebases and kernel interfaces.

In practice, statbuf often represents a buffer or structure that holds metadata about a file as returned by stat, fstat, or lstat. The exact definition is platform-dependent. On many systems, statbuf corresponds to the standard POSIX struct stat or to a kernel-internal variant that is mapped to user-space through the stat family of system calls. The fields typically included are device ID (st_dev), inode number (st_ino), file mode (st_mode), number of hard links (st_nlink), user ID (st_uid) and group ID (st_gid), size in bytes (st_size), block size for I/O (st_blksize), and number of allocated blocks (st_blocks). Time fields for last access, modification, and status change are usually present as well (st_atime, st_mtime, st_ctime), with newer layouts sometimes offering nanosecond-resolution counterparts (st_atim, st_mtim, st_ctim).

Usage-wise, a statbuf-like structure is filled by a stat-family system call and then inspected to determine properties such as file type, permissions, size, and timestamps. In kernel code or low-level libraries, it may represent an internal temporary storage used during the implementation of stat-related functionality.

Compatibility varies by platform; statbuf is not a universal type. When encountered, refer to the system’s headers to determine the exact structure and field names. See also: stat, struct stat, fstat, lstat, stat64, kstat.