LinuxGuruz
  • Last 5 Forum Topics
    Replies
    Views
    Last post


The Web Only This Site
  • BOOKMARK

  • ADD TO FAVORITES

  • REFERENCES


  • MARC

    Mailing list ARChives
    - Search by -
     Subjects
     Authors
     Bodies





    FOLDOC

    Computing Dictionary




  • Text Link Ads






  • LINUX man pages
  • Linux Man Page Viewer


    The following form allows you to view linux man pages.

    Command:

    sem_open

    
    
    

    SYNOPSIS

           #include <fcntl.h>           /* For O_* constants */
           #include <sys/stat.h>        /* For mode constants */
           #include <semaphore.h>
    
           sem_t *sem_open(const char *name, int oflag);
           sem_t *sem_open(const char *name, int oflag,
                           mode_t mode, unsigned int value);
    
           Link with -pthread.
    
    
    

    DESCRIPTION

           sem_open()   creates  a  new  POSIX  semaphore  or  opens  an  existing
           semaphore.  The semaphore is identified by name.  For  details  of  the
           construction of name, see sem_overview(7).
    
           The  oflag  argument  specifies flags that control the operation of the
           call.  (Definitions of the flags values can be  obtained  by  including
           <fcntl.h>.)   If  O_CREAT  is specified in oflag, then the semaphore is
           created if it does not already exist.   The  owner  (user  ID)  of  the
           semaphore  is set to the effective user ID of the calling process.  The
           group ownership (group ID) is set to the  effective  group  ID  of  the
           calling  process.   If  both O_CREAT and O_EXCL are specified in oflag,
           then an error is returned if a semaphore with the  given  name  already
           exists.
    
           If O_CREAT is specified in oflag, then two additional arguments must be
           supplied.  The mode argument specifies the permissions to be placed  on
           the  new semaphore, as for open(2).  (Symbolic definitions for the per-
           missions bits can be obtained by including <sys/stat.h>.)  The  permis-
           sions  settings  are  masked  against the process umask.  Both read and
           write permission should be granted to each  class  of  user  that  will
           access  the  semaphore.  The value argument specifies the initial value
           for the new semaphore.  If O_CREAT is specified, and a  semaphore  with
           the given name already exists, then mode and value are ignored.
    
    
    

    RETURN VALUE

           On  success,  sem_open() returns the address of the new semaphore; this
           address is used when calling  other  semaphore-related  functions.   On
           error,  sem_open()  returns  SEM_FAILED, with errno set to indicate the
           error.
    
    
    

    ERRORS

           EACCES The semaphore exists, but the caller does not have permission to
                  open it.
    
           EEXIST Both O_CREAT and O_EXCL were specified in oflag, but a semaphore
                  with this name already exists.
    
           EINVAL value was greater than SEM_VALUE_MAX.
    
           EINVAL name consists of just "/", followed by no other characters.
    
    
    

    CONFORMING TO

           POSIX.1-2001.
    
    
    

    SEE ALSO

           sem_close(3), sem_getvalue(3), sem_post(3), sem_unlink(3), sem_wait(3),
           sem_overview(7)
    
    
    

    Linux 2012-05-13 SEM_OPEN(3)

    
    
  • MORE RESOURCE


  • Linux

    The Distributions





    Linux

    The Software





    Linux

    The News



  • MARKETING






  • Toll Free

webmaster@linuxguruz.com
Copyright © 1999 - 2016 by LinuxGuruz