PTHREAD_MAIN_NP(3) | Library Functions Manual | PTHREAD_MAIN_NP(3)

# NAME

`pthread_main_np` — identify the main thread

# SYNOPSIS

POSIX Threads Library (libpthread, -lpthread)
`#include <pthread.h>`
`#include <pthread_np.h>`

int
`pthread_main_np`(void);

# DESCRIPTION

The `pthread_main_np`() function identifies the main thread.

# RETURN VALUES

The `pthread_main_np`() function returns:

1
  if the calling thread is the main thread
0
  if the calling thread is not the main thread
-1
  if the thread initialization has not completed

# SEE ALSO

pthread_self(3), pthreads(3)

# STANDARDS

The `pthread_main_np`() function is non-portable and may not be supported with the above semantics on other POSIX systems.

June 7, 2025 | Debian