I have made a Linux CUI app that communicates between processes via Message-quene.
我制作了一个Linux CUI应用，通过消息-quene在进程之间进行通信。
There is no problem with it as long as it is a single instance. However when there are multiple instances of the same app, the messages in the quene get sent to the wrong instance.
只要是一个实例，就没有问题。然而，当同一应用程序有多个实例时，quene中的消息会被发送到错误的实例。
I understand this can be avoided by giving the msgget function a unique key. Using ftok() to create a key, but since the variables are the same they result in identical keys.
我知道可以通过给msgget函数一个唯一的键来避免这种情况。使用ftok()创建一个密钥，但是由于变量是相同的，它们会产生相同的密钥。
Can someone guide me how to have a unique key for each instance?
是否有人可以指导我如何为每个实例设置唯一的键?
The only idea I have now is to randamize the variable given to ftok, and I know that cant be right.
我现在唯一的想法是将给ftok的变量随机化，我知道这是不对的。
4 个解决方案
#1
2
Be careful with ftok!
小心ftok !
This will only be unique for a given file system and only if then if the file system is not heavily used. fttok is driven by the file entry number in the file system.
这只对给定的文件系统是唯一的，并且只有在文件系统没有被大量使用的情况下。fttok由文件系统中的文件条目号驱动。
This used to be a pretty good way of getting unique values but time and Moores law caught up with it a few years ago. It works on the lower 8 bits of the file number but the actual file number is now 32 bits and numbering starts again for each file system.
这曾经是获得独特价值的一种很好的方式，但是时间和摩尔定律在几年前赶上了它。它在文件号的下8位上工作，但是实际的文件号现在是32位，每个文件系统的编号都重新开始。
Process id is a pretty good choice, they do get re-cycled but not as long as the process is still alive.
进程id是一个不错的选择，它们确实会被重新循环，但只要进程还活着，就不会被循环使用。
#3
0
Looking globally unique ids usually called Guid or Uuid. There must be a library you can use to generate them. They are unique strings made from your nic address, the current time, and a random number.
查找全局惟一的id，通常称为Guid或uid。必须有一个可以用来生成它们的库。它们是由nic地址、当前时间和随机数组成的唯一字符串。
#4
0
How about the clock? WikiPedia say's it's better than RDTSC (and SMP safe).
钟怎么样?*说它比RDTSC(和SMP保险箱)要好。
"Under Linux, similar functionality is provided by reading the value of CLOCK_MONOTONIC clock using POSIX clock_gettime function."
“在Linux下，通过使用POSIX clock_gettime函数读取clock_单调时钟的值，可以提供类似的功能。”
#1
2
Be careful with ftok!
小心ftok !
This will only be unique for a given file system and only if then if the file system is not heavily used. fttok is driven by the file entry number in the file system.
这只对给定的文件系统是唯一的，并且只有在文件系统没有被大量使用的情况下。fttok由文件系统中的文件条目号驱动。
This used to be a pretty good way of getting unique values but time and Moores law caught up with it a few years ago. It works on the lower 8 bits of the file number but the actual file number is now 32 bits and numbering starts again for each file system.
这曾经是获得独特价值的一种很好的方式，但是时间和摩尔定律在几年前赶上了它。它在文件号的下8位上工作，但是实际的文件号现在是32位，每个文件系统的编号都重新开始。
Process id is a pretty good choice, they do get re-cycled but not as long as the process is still alive.
进程id是一个不错的选择，它们确实会被重新循环，但只要进程还活着，就不会被循环使用。
#2
#3
0
Looking globally unique ids usually called Guid or Uuid. There must be a library you can use to generate them. They are unique strings made from your nic address, the current time, and a random number.
查找全局惟一的id，通常称为Guid或uid。必须有一个可以用来生成它们的库。它们是由nic地址、当前时间和随机数组成的唯一字符串。
#4
0
How about the clock? WikiPedia say's it's better than RDTSC (and SMP safe).
钟怎么样?*说它比RDTSC(和SMP保险箱)要好。
"Under Linux, similar functionality is provided by reading the value of CLOCK_MONOTONIC clock using POSIX clock_gettime function."
“在Linux下，通过使用POSIX clock_gettime函数读取clock_单调时钟的值，可以提供类似的功能。”