gettid - get thread identification


   #include <sys/types.h>

   pid_t gettid(void);

   Note: There is no glibc wrapper for this system call; see NOTES.


   gettid()  returns  the  caller's thread ID (TID).  In a single-threaded
   process, the thread ID is equal to the process ID (PID, as returned  by
   getpid(2)).  In a multithreaded process, all threads have the same PID,
   but each one has a unique TID.  For further details, see the discussion
   of CLONE_THREAD in clone(2).


   On success, returns the thread ID of the calling process.


   This call is always successful.


   The gettid() system call first appeared on Linux in kernel 2.4.11.


   gettid()  is Linux-specific and should not be used in programs that are
   intended to be portable.


   Glibc does not provide a wrapper for this system call;  call  it  using

   The  thread  ID  returned by this call is not the same thing as a POSIX
   thread ID (i.e., the opaque value returned by pthread_self(3)).

   In a new thread group created by a clone(2) call that does not  specify
   the  CLONE_THREAD  flag  (or,  equivalently,  a  new process created by
   fork(2)), the new process is a thread  group  leader,  and  its  thread
   group ID (the value returned by getpid(2)) is the same as its thread ID
   (the value returned by gettid()).


   capget(2),    clone(2),    fcntl(2),    fork(2),    get_robust_list(2),
   ioprio_set(2),         perf_event_open(2),        sched_setaffinity(2),
   sched_setparam(2), sched_setscheduler(2), tgkill(2), timer_create(2)


   This page is part of release 4.09 of the Linux  man-pages  project.   A
   description  of  the project, information about reporting bugs, and the
   latest    version    of    this    page,    can     be     found     at


Personal Opportunity - Free software gives you access to billions of dollars of software at no cost. Use this software for your business, personal use or to develop a profitable skill. Access to source code provides access to a level of capabilities/information that companies protect though copyrights. Open source is a core component of the Internet and it is available to you. Leverage the billions of dollars in resources and capabilities to build a career, establish a business or change the world. The potential is endless for those who understand the opportunity.

Business Opportunity - Goldman Sachs, IBM and countless large corporations are leveraging open source to reduce costs, develop products and increase their bottom lines. Learn what these companies know about open source and how open source can give you the advantage.

Free Software

Free Software provides computer programs and capabilities at no cost but more importantly, it provides the freedom to run, edit, contribute to, and share the software. The importance of free software is a matter of access, not price. Software at no cost is a benefit but ownership rights to the software and source code is far more significant.

Free Office Software - The Libre Office suite provides top desktop productivity tools for free. This includes, a word processor, spreadsheet, presentation engine, drawing and flowcharting, database and math applications. Libre Office is available for Linux or Windows.

Free Books

The Free Books Library is a collection of thousands of the most popular public domain books in an online readable format. The collection includes great classical literature and more recent works where the U.S. copyright has expired. These books are yours to read and use without restrictions.

Source Code - Want to change a program or know how it works? Open Source provides the source code for its programs so that anyone can use, modify or learn how to write those programs themselves. Visit the GNU source code repositories to download the source.


Study at Harvard, Stanford or MIT - Open edX provides free online courses from Harvard, MIT, Columbia, UC Berkeley and other top Universities. Hundreds of courses for almost all major subjects and course levels. Open edx also offers some paid courses and selected certifications.

Linux Manual Pages - A man or manual page is a form of software documentation found on Linux/Unix operating systems. Topics covered include computer programs (including library and system calls), formal standards and conventions, and even abstract concepts.