Why when I run `$ ipcs` are all shared memory segment keys â0x00000000â?
Clash Royale CLAN TAG#URR8PPP
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So when I run $ ipcs
, the shared memory segment
section returns a variety of results:
------ Shared Memory Segments --------
key shmid owner perms bytes nattch status
0x00000000 524288 jvn 600 524288 2 dest
0x00000000 1048577 jvn 600 524288 2 dest
0x00000000 1769474 jvn 600 393216 2 dest
0x00000000 753667 jvn 600 524288 2 dest
0x00000000 1146884 jvn 600 16777216 2
The 0x00000000
value is present in every IPC object, why does it not differ? What does it mean?
To provide more context, the TLDP states:
To obtain a unique ID, a key must be used. The key must be mutually agreed upon by both client and server processes. This represents the first step in constructing a client/server framework for an application.
When you use a telephone to call someone, you must know their number. In addition, the phone company must know how to relay your outgoing call to its final destination. Once the other party responds by answering the telephone call, the connection is made.
In the case of System V IPC facilities, the
telephone'' correllates directly with the type of object being used. The
phone company'', or routing method, can be directly associated with an IPC key.
The key can be the same value every time, by hardcoding a key value into an application. This has the disadvantage of the key possibly being in use already. Often, the ftok() function is used to generate key values for both the client and the server.
linux ipc sysv
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up vote
-1
down vote
favorite
So when I run $ ipcs
, the shared memory segment
section returns a variety of results:
------ Shared Memory Segments --------
key shmid owner perms bytes nattch status
0x00000000 524288 jvn 600 524288 2 dest
0x00000000 1048577 jvn 600 524288 2 dest
0x00000000 1769474 jvn 600 393216 2 dest
0x00000000 753667 jvn 600 524288 2 dest
0x00000000 1146884 jvn 600 16777216 2
The 0x00000000
value is present in every IPC object, why does it not differ? What does it mean?
To provide more context, the TLDP states:
To obtain a unique ID, a key must be used. The key must be mutually agreed upon by both client and server processes. This represents the first step in constructing a client/server framework for an application.
When you use a telephone to call someone, you must know their number. In addition, the phone company must know how to relay your outgoing call to its final destination. Once the other party responds by answering the telephone call, the connection is made.
In the case of System V IPC facilities, the
telephone'' correllates directly with the type of object being used. The
phone company'', or routing method, can be directly associated with an IPC key.
The key can be the same value every time, by hardcoding a key value into an application. This has the disadvantage of the key possibly being in use already. Often, the ftok() function is used to generate key values for both the client and the server.
linux ipc sysv
add a comment |Â
up vote
-1
down vote
favorite
up vote
-1
down vote
favorite
So when I run $ ipcs
, the shared memory segment
section returns a variety of results:
------ Shared Memory Segments --------
key shmid owner perms bytes nattch status
0x00000000 524288 jvn 600 524288 2 dest
0x00000000 1048577 jvn 600 524288 2 dest
0x00000000 1769474 jvn 600 393216 2 dest
0x00000000 753667 jvn 600 524288 2 dest
0x00000000 1146884 jvn 600 16777216 2
The 0x00000000
value is present in every IPC object, why does it not differ? What does it mean?
To provide more context, the TLDP states:
To obtain a unique ID, a key must be used. The key must be mutually agreed upon by both client and server processes. This represents the first step in constructing a client/server framework for an application.
When you use a telephone to call someone, you must know their number. In addition, the phone company must know how to relay your outgoing call to its final destination. Once the other party responds by answering the telephone call, the connection is made.
In the case of System V IPC facilities, the
telephone'' correllates directly with the type of object being used. The
phone company'', or routing method, can be directly associated with an IPC key.
The key can be the same value every time, by hardcoding a key value into an application. This has the disadvantage of the key possibly being in use already. Often, the ftok() function is used to generate key values for both the client and the server.
linux ipc sysv
So when I run $ ipcs
, the shared memory segment
section returns a variety of results:
------ Shared Memory Segments --------
key shmid owner perms bytes nattch status
0x00000000 524288 jvn 600 524288 2 dest
0x00000000 1048577 jvn 600 524288 2 dest
0x00000000 1769474 jvn 600 393216 2 dest
0x00000000 753667 jvn 600 524288 2 dest
0x00000000 1146884 jvn 600 16777216 2
The 0x00000000
value is present in every IPC object, why does it not differ? What does it mean?
To provide more context, the TLDP states:
To obtain a unique ID, a key must be used. The key must be mutually agreed upon by both client and server processes. This represents the first step in constructing a client/server framework for an application.
When you use a telephone to call someone, you must know their number. In addition, the phone company must know how to relay your outgoing call to its final destination. Once the other party responds by answering the telephone call, the connection is made.
In the case of System V IPC facilities, the
telephone'' correllates directly with the type of object being used. The
phone company'', or routing method, can be directly associated with an IPC key.
The key can be the same value every time, by hardcoding a key value into an application. This has the disadvantage of the key possibly being in use already. Often, the ftok() function is used to generate key values for both the client and the server.
linux ipc sysv
linux ipc sysv
asked Sep 8 at 17:28
John Von Neumann
1387
1387
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1 Answer
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up vote
0
down vote
Found the answer through a course online, from the Linux Foundation Certified Sysadmin content:
Note almost all of the currently running shared memory segments have a
key of0
or0x00000000
(also known as IPC_PRIVATE) which means
they are only shared between processes in a parent/child relationship.
add a comment |Â
1 Answer
1
active
oldest
votes
1 Answer
1
active
oldest
votes
active
oldest
votes
active
oldest
votes
up vote
0
down vote
Found the answer through a course online, from the Linux Foundation Certified Sysadmin content:
Note almost all of the currently running shared memory segments have a
key of0
or0x00000000
(also known as IPC_PRIVATE) which means
they are only shared between processes in a parent/child relationship.
add a comment |Â
up vote
0
down vote
Found the answer through a course online, from the Linux Foundation Certified Sysadmin content:
Note almost all of the currently running shared memory segments have a
key of0
or0x00000000
(also known as IPC_PRIVATE) which means
they are only shared between processes in a parent/child relationship.
add a comment |Â
up vote
0
down vote
up vote
0
down vote
Found the answer through a course online, from the Linux Foundation Certified Sysadmin content:
Note almost all of the currently running shared memory segments have a
key of0
or0x00000000
(also known as IPC_PRIVATE) which means
they are only shared between processes in a parent/child relationship.
Found the answer through a course online, from the Linux Foundation Certified Sysadmin content:
Note almost all of the currently running shared memory segments have a
key of0
or0x00000000
(also known as IPC_PRIVATE) which means
they are only shared between processes in a parent/child relationship.
answered Sep 9 at 11:48
John Von Neumann
1387
1387
add a comment |Â
add a comment |Â
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