UNIX System Call

File Locking API

POSIX advisory file locking interfaces for coordinating file access between processes.

GitHub

Documentation

📖
Documentation
https://man7.org/linux/man-pages/man2/fcntl.2.html
📖
Documentation
https://pubs.opengroup.org/onlinepubs/9699919799/functions/fcntl.html

Work with this as data

Every API here is available over the APIs.io API and to AI agents over MCP.

MCP server

One button, every client — Claude, Cursor, VS Code and the rest.

https://apis.io/mcp

Tools for apis

7 MCP tools reach this
  • find_apisBrowse and filter every API in the catalog.
  • get_api_artifactsOne API's artifacts, grouped by type.
  • get_openapiThe primary OpenAPI for this API.
  • find_similar_apisAPIs that look like this one.
  • apis_io_searchSTART HERE — APIs, providers and tags for one query, each with its total.
  • resolveTurn a domain, URL or GitHub org into the provider it belongs to.
  • find_cohortsEvery scored population of providers in the catalog.
All 92 tools

Call it yourself

curl for this page
This API 
curl "https://apis.io/api/v1/apis/file-locking-api"
All apis 
curl "https://apis.io/api/v1/apis?limit=25"

Discovery needs no key. Ratings and market analysis are Pro.

Get an API key

Free tier, no email required.

GitHub Google LinkedIn

A second provider on the same verified email joins the account you already have.

API entry from apis.yml

apis.yml Raw ↑ 
name: File Locking API
description: POSIX advisory file locking interfaces for coordinating file access between processes.
image: https://kinlane-images.s3.amazonaws.com/shared/apis-json/apis-json-logo.jpg
humanURL: https://man7.org/linux/man-pages/man2/fcntl.2.html
baseURL: system://unix/file-locking
tags:
- Advisory-Locking
- Concurrency
- Fcntl
- File-Locking
properties:
- type: Documentation
  url: https://man7.org/linux/man-pages/man2/fcntl.2.html
- type: Documentation
  url: https://pubs.opengroup.org/onlinepubs/9699919799/functions/fcntl.html
operations:
- name: fcntl (F_SETLK)
  description: Set or release an advisory file lock without blocking
  parameters:
  - fd
  - F_SETLK
  - flock
  returns: 0 on success, -1 on error
- name: fcntl (F_SETLKW)
  description: Set an advisory file lock, blocking if necessary
  parameters:
  - fd
  - F_SETLKW
  - flock
  returns: 0 on success, -1 on error
- name: fcntl (F_GETLK)
  description: Test for the existence of a lock on a file region
  parameters:
  - fd
  - F_GETLK
  - flock
  returns: 0 on success, -1 on error
- name: flock
  description: Apply or remove an advisory lock on an open file
  parameters:
  - fd
  - operation
  returns: 0 on success, -1 on error
- name: lockf
  description: Apply, test, or remove a POSIX lock on an open file section
  parameters:
  - fd
  - cmd
  - len
  returns: 0 on success, -1 on error