1<sys/shm.h>(0P)            POSIX Programmer's Manual           <sys/shm.h>(0P)
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NAME

6       sys/shm.h - XSI shared memory facility
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SYNOPSIS

9       #include <sys/shm.h>
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DESCRIPTION

12       The <sys/shm.h> header shall define the following symbolic constants:
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14       SHM_RDONLY
15              Attach read-only (else read-write).
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17       SHM_RND
18              Round attach address to SHMLBA.
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21       The <sys/shm.h> header shall define the following symbolic value:
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23       SHMLBA Segment low boundary address multiple.
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26       The following data types shall be defined through typedef:
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28       shmatt_t
29              Unsigned  integer  used  for the number of current attaches that
30              must be able to store  values  at  least  as  large  as  a  type
31              unsigned short.
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34       The shmid_ds structure shall contain the following members:
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37              struct ipc_perm shm_perm   Operation permission structure.
38              size_t          shm_segsz  Size of segment in bytes.
39              pid_t           shm_lpid   Process ID of last shared memory operation.
40              pid_t           shm_cpid   Process ID of creator.
41              shmatt_t        shm_nattch Number of current attaches.
42              time_t          shm_atime  Time of last shmat
43               ().
44              time_t          shm_dtime  Time of last shmdt
45               ().
46              time_t          shm_ctime  Time of last change by shmctl
47               ().
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49       The  pid_t,  time_t,  key_t,  and  size_t  types  shall  be  defined as
50       described in <sys/types.h> .
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52       The following shall be declared as functions and may also be defined as
53       macros. Function prototypes shall be provided.
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56              void *shmat(int, const void *, int);
57              int   shmctl(int, int, struct shmid_ds *);
58              int   shmdt(const void *);
59              int   shmget(key_t, size_t, int);
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61       In  addition, all of the symbols from <sys/ipc.h> shall be defined when
62       this header is included.
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64       The following sections are informative.
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APPLICATION USAGE

67       None.
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RATIONALE

70       None.
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FUTURE DIRECTIONS

73       None.
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SEE ALSO

76       <sys/ipc.h>,   <sys/types.h>,   the   System   Interfaces   volume   of
77       IEEE Std 1003.1-2001, shmat(), shmctl(), shmdt(), shmget()
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80       Portions  of  this text are reprinted and reproduced in electronic form
81       from IEEE Std 1003.1, 2003 Edition, Standard for Information Technology
82       --  Portable  Operating  System  Interface (POSIX), The Open Group Base
83       Specifications Issue 6, Copyright (C) 2001-2003  by  the  Institute  of
84       Electrical  and  Electronics  Engineers, Inc and The Open Group. In the
85       event of any discrepancy between this version and the original IEEE and
86       The  Open Group Standard, the original IEEE and The Open Group Standard
87       is the referee document. The original Standard can be  obtained  online
88       at http://www.opengroup.org/unix/online.html .
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92IEEE/The Open Group                  2003                      <sys/shm.h>(0P)
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