HP-UX Reference (11i v1 00/12) - 2 System Calls (vol 5)

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STANDARD Printed by: Nora Chuang [nchuang] STANDARD

/build/1111/BRICK/man2/!!!intro.2

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shmctl(2) shmctl(2)

[EINVAL] cmd is not a valid command, or the command contains invalid parameters.

[ENOMEM] cmd is equal to SHM_LOCK and there is not sufﬁcient lockable memory to ﬁll the

request.

[EPERM] cmd is equal to IPC_RMID, IPC_SET, SHM_LOCK,orSHM_UNLOCK and the

effective user ID of the calling process is not equal to that of a user having appropriate

privileges and it is not equal to the value of either shm_perm.uid or

shm_perm.cuid in the data structure associated with shmid.

[EPERM] cmd is equal to SHM_LOCK or SHM_UNLOCK and the effective user ID of the calling

process is not equal to that of a user having appropriate privileges and the calling pro-

cess does not have the PRIV_MLOCK privilege (see getprivgrp(2)).

EXAMPLES

The following call to shmctl() locks in memory the shared memory segment represented by myshmid.

This example assumes the process has a valid shmid, which can be obtained by calling shmget(2).

shmctl (myshmid, SHM_LOCK, 0);

The following call to shmctl() removes the shared memory segment represented by

myshmid. This

example assumes the process has a valid shmid, which can be obtained by calling

shmget() (see

shmget(2).

shmctl (myshmid, IPC_RMID, 0);

AUTHOR

shmctl() was developed by AT&T and HP.