---
name: "pthread_kill"
section: "2"
platform: "macos"
package: "libpthread"
version: "539.100.4"
release: "macOS 26.5"
platforms: ["macos"]
url: "https://new.carta.tech/pthread_kill"
---

# pthread\_kill(2)

send a signal to a specified thread

## NAME

**pthread\_kill** – send a signal to a specified thread

## SYNOPSIS

**#include \<signal.h\>**

*int*\

**pthread\_kill**(*pthread\_t thread*, *int sig*);

## DESCRIPTION

The **pthread\_kill**() function sends a signal, specified by *sig*, to a thread, specified by *thread*. If *sig* is 0, error checking is performed, but no signal is actually sent.

## RETURN VALUES

If successful, **pthread\_kill**() returns 0. Otherwise, an error number is returned.

## ERRORS

The **pthread\_kill**() function will fail if:

- \[ESRCH\]

  *thread* is an invalid thread ID.

- \[EINVAL\]

  *sig* is an invalid or unsupported signal number.

- \[ENOTSUP\]

  *thread* was not created by **pthread\_create**() and does not support being killed with **pthread\_kill**()

## LEGACY SYNOPSIS

**#include \<pthread.h\>** **#include \<signal.h\>**

The include file ⟨pthread.h⟩ is necessary.

## SEE ALSO

[kill(2)](/kill/2.md), [pthread\_self(3)](/pthread_self/3.md), [raise(3)](/raise/3.md), [compat(5)](/compat/5.md)

## STANDARDS

**pthread\_kill**() conforms to ISO/IEC 9945-1:1996 (\`\`POSIX.1'')