NOMBRE

       getpid, getppid - obtiene el identificador de proceso

BIBLIOTECA

       Biblioteca Estándar C (libc, -lc)

SINOPSIS

       #include <unistd.h>

       pid_t getpid(void);
       pid_t getppid(void);

DESCRIPCIÓN

       getpid  devuelve  el  identificador de proceso (PID) del proceso actual. Esto suele ser usado por rutinas
       que generan nombres únicos de archivos temporales.

       getppid()  returns the process ID of the parent of the calling process.  This will be either  the  ID  of
       the process that created this process using fork(), or, if that process has already terminated, the ID of
       the  process  to which this process has been reparented (either init(1)  or a "subreaper" process defined
       via the prctl(2)  PR_SET_CHILD_SUBREAPER operation).

ERRORES

       Estas funciones siempre terminan sin error.

ESTÁNDARES

       POSIX.1-2001, POSIX.1-2008, 4.3BSD, SVr4.

NOTAS

       Si  el  antecesor  del  invocante  está  en  un  espacio  de   nombres   diferente   al   PID   (consulte
       pid_namespaces(7)), getppid() tendrá un estado de salida de 0.

       From a kernel perspective, the PID (which is shared by all of the threads in a multithreaded process)  is
       sometimes  also  known  as  the  thread group ID (TGID).  This contrasts with the kernel thread ID (TID),
       which is unique for each thread.   For  further  details,  see  gettid(2)   and  the  discussion  of  the
       CLONE_THREAD flag in clone(2).

   Diferencias núcleo / biblioteca C
       From  glibc  2.3.4  up to and including glibc 2.24, the glibc wrapper function for getpid()  cached PIDs,
       with the goal of avoiding additional system calls when a process calls  getpid()   repeatedly.   Normally
       this  caching  was  invisible,  but  its correct operation relied on support in the wrapper functions for
       fork(2), vfork(2), and clone(2): if an application bypassed the glibc wrappers for these system calls  by
       using  syscall(2),  then a call to getpid()  in the child would return the wrong value (to be precise: it
       would return the PID of the parent process).  In addition, there were cases where getpid()  could  return
       the  wrong  value  even when invoking clone(2)  via the glibc wrapper function.  (For a discussion of one
       such case, see BUGS in clone(2).)  Furthermore, the complexity of the caching code had been the source of
       a few bugs within glibc over the years.

       Because of the aforementioned problems, since glibc 2.25, the PID cache is  removed:  calls  to  getpid()
       always invoke the actual system call, rather than returning a cached value.

       On  Alpha, instead of a pair of getpid()  and getppid()  system calls, a single getxpid()  system call is
       provided, which returns a pair of PID and  parent  PID.   The  glibc  getpid()   and  getppid()   wrapper
       functions transparently deal with this.  See syscall(2)  for details regarding register mapping.

VÉASE TAMBIÉN

       clone(2),   fork(2),   gettid(2),   kill(2),  exec(3),  mkstemp(3),  tempnam(3),  tmpfile(3),  tmpnam(3),
       credentials(7), pid_namespaces(7)

TRADUCCIÓN

       La traducción al español de esta página del manual fue creada por Nicolás  Lichtmaier  <nick@debian.org>,
       Juan Piernas <piernas@ditec.um.es> y Marcos Fouces <marcos@debian.org>

       Esta  traducción  es  documentación  libre;  lea  la GNU General Public License Version 3 o posterior con
       respecto a las condiciones de copyright.  No existe NINGUNA RESPONSABILIDAD.

       Si encuentra algún error en la traducción de esta página  del  manual,  envíe  un  correo  electrónico  a
       debian-l10n-spanish@lists.debian.org.

Páginas de manual de Linux 6.03                   22 Enero 2023                                        getpid(2)