File System Operations API

name: File System Operations API
description: System calls for file and directory manipulation, including open, read, write, and file descriptor
  management.
image: https://kinlane-images.s3.amazonaws.com/shared/apis-json/apis-json-logo.jpg
humanURL: https://man7.org/linux/man-pages/dir_section_2.html
baseURL: system://unix/fs
tags:
- Directories
- File
- Filesystem
- IO
tags_raw:
- Directories
- Files
- Filesystem
- Io
properties:
- type: Documentation
  url: https://pubs.opengroup.org/onlinepubs/9699919799/functions/contents.html
- type: APIReference
  url: https://man7.org/linux/man-pages/man2/
- type: Documentation
  url: https://pubs.opengroup.org/onlinepubs/9799919799/functions/open.html
contact:
- FN: POSIX Standards Committee
  email: standards@opengroup.org
operations:
- name: open
  description: Open file and return file descriptor
  parameters:
  - pathname
  - flags
  - mode
  returns: file descriptor (int)
- name: read
  description: Read bytes from a file descriptor
  parameters:
  - fd
  - buf
  - count
  returns: number of bytes read
- name: write
  description: Write bytes to a file descriptor
  parameters:
  - fd
  - buf
  - count
  returns: number of bytes written
- name: close
  description: Close a file descriptor
  parameters:
  - fd
  returns: 0 on success, -1 on error
- name: lseek
  description: Reposition file offset
  parameters:
  - fd
  - offset
  - whence
  returns: resulting offset
- name: stat
  description: Get file status
  parameters:
  - pathname
  - statbuf
  returns: 0 on success, -1 on error
- name: fstat
  description: Get file status by file descriptor
  parameters:
  - fd
  - statbuf
  returns: 0 on success, -1 on error
- name: lstat
  description: Get file status without following symbolic links
  parameters:
  - pathname
  - statbuf
  returns: 0 on success, -1 on error
- name: chmod
  description: Change file permissions
  parameters:
  - pathname
  - mode
  returns: 0 on success, -1 on error
- name: fchmod
  description: Change file permissions by file descriptor
  parameters:
  - fd
  - mode
  returns: 0 on success, -1 on error
- name: chown
  description: Change file owner and group
  parameters:
  - pathname
  - owner
  - group
  returns: 0 on success, -1 on error
- name: mkdir
  description: Create a directory
  parameters:
  - pathname
  - mode
  returns: 0 on success, -1 on error
- name: rmdir
  description: Remove a directory
  parameters:
  - pathname
  returns: 0 on success, -1 on error
- name: link
  description: Create a hard link to a file
  parameters:
  - oldpath
  - newpath
  returns: 0 on success, -1 on error
- name: unlink
  description: Delete a name and possibly the file it refers to
  parameters:
  - pathname
  returns: 0 on success, -1 on error
- name: symlink
  description: Create a symbolic link
  parameters:
  - target
  - linkpath
  returns: 0 on success, -1 on error
- name: readlink
  description: Read value of a symbolic link
  parameters:
  - pathname
  - buf
  - bufsiz
  returns: number of bytes placed in buf
- name: rename
  description: Change the name or location of a file
  parameters:
  - oldpath
  - newpath
  returns: 0 on success, -1 on error
- name: dup
  description: Duplicate a file descriptor
  parameters:
  - oldfd
  returns: new file descriptor
- name: dup2
  description: Duplicate a file descriptor to a specified descriptor number
  parameters:
  - oldfd
  - newfd
  returns: new file descriptor
- name: fcntl
  description: Manipulate file descriptor properties and flags
  parameters:
  - fd
  - cmd
  - arg
  returns: depends on cmd, -1 on error
- name: access
  description: Check user permissions for a file
  parameters:
  - pathname
  - mode
  returns: 0 on success, -1 on error
- name: umask
  description: Set file mode creation mask
  parameters:
  - mask
  returns: previous value of the mask
- name: opendir
  description: Open a directory stream
  parameters:
  - name
  returns: pointer to directory stream
- name: readdir
  description: Read a directory entry
  parameters:
  - dirp
  returns: pointer to dirent structure
- name: closedir
  description: Close a directory stream
  parameters:
  - dirp
  returns: 0 on success, -1 on error
- name: chdir
  description: Change working directory
  parameters:
  - path
  returns: 0 on success, -1 on error
- name: getcwd
  description: Get current working directory
  parameters:
  - buf
  - size
  returns: pointer to buf
- name: truncate
  description: Truncate a file to a specified length
  parameters:
  - path
  - length
  returns: 0 on success, -1 on error
- name: ftruncate
  description: Truncate an open file to a specified length
  parameters:
  - fd
  - length
  returns: 0 on success, -1 on error
- name: fsync
  description: Synchronize file state with storage device
  parameters:
  - fd
  returns: 0 on success, -1 on error