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
       ⟨https://www.gnu.org/licenses/gpl-3.0.html⟩ 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⟩.