HP-UX Reference (11i v2 03/08) - 5 Miscellaneous Topics, 7 Device (Special) Files, 9 General Information, Index (vol 9)

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glossary(9) glossary(9)
shm_segsz specifies the size of the shared memory segment.
shm_cpid is the process
id of the process that created the shared memory identifier.
shm_lpid is the process id
of the last process that performed a shmop(2) operation.
shm_nattch is the number of
processes that currently have this segment attached.
shm_atime
is the time of the last
shmat operation, shm_dtime is the time of the last
shmdt operation, and
shm_ctime is the time of the last shmctl (2) operation that changed one of the members
of the above structure.
shared memory operation permissions
In the shmop(2) and shmctl(2) system call descriptions, the permission required for an
operation is indicated for each operation. Whether a particular process has the permis-
sion to perform a shmop(2) or shmctl(2) operation on an object is determined by the
object’s permission mode bits as follows:
00400 Read by user
00200 Write by user
00060 Read, Write by group
00006 Read, Write by others
Read and Write permissions for a shmop(2) or shmctl (2) operation on a shared memory
identifier (shmid) are granted to a process if one or more of the following are true:
• The process’s effective user ID is superuser.
• The process’s effective user ID matches
shm_perm.[c]uid in the data structure
associated with the shmid and the appropriate bit of the ‘‘user’’ portion (0600) of
shm_perm.mode is set.
• The process’s effective user ID does not match
shm_perm.[c]uid and either
the process’s effective group ID matches
shm_perm.
[c]gid or one of
shm_perm.[c]gid is in the process’s group access list and the appropriate bit
of the ‘‘group’’ portion (060) of shm_perm.mode
is set.
• The process’s effective user ID does not match
shm_perm.[c]uid and the
process’s effective group ID does not match
shm_perm.[c]gid and neither of
shm_perm.[c]gid is in the process’s group access list and the appropriate bit
of the ‘‘other’’ portion (06) of shm_perm.mode
is set.
Otherwise, the corresponding permissions are denied.
shell A user interface to the HP-UX operating system. A shell often functions as both a com-
mand interpreter and an interpretive programming language. A shell is automatically
invoked for every user who logs in. See sh(1) and its related manual entries plus the
tutorials supplied with your system for details.
shell program
See shell script.
shell script A sequence of shell commands and shell programming language constructs stored in a file
and invoked as a user command (program). No compilation is needed prior to execution
because the shell recognizes the commands and constructs that make up the shell pro-
gramming language. A shell script is often called a shell program or a command file.
See the Shells User Guide.
shmid See shared memory identifier.
signal A software interrupt sent to a process, informing it of special situations or events. Also,
the event itself. See signal(2).
single-user state
A condition of the HP-UX operating system in which the system console provides the only
communication mechanism between the system and its user. By convention, single-user
state is usually specified by init(1M) as run-level
S or s. Do not confuse single-user
state, in which the software is limiting a multiuser system to a single-user communica-
tion, with a single-user system, which can never communicate with more than one fixed
terminal. See also multiuser state.
slash The literal character
/.Apath name consisting of a single slash resolves to the root
directory of the process. See also path name resolution.
HP-UX 11i Version 2: August 2003 − 20 − Hewlett-Packard Company Section 9−−21