Talk:Fork (operating system)
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[edit] Fork is not critical to the Unix design philosophy
Forking is an important part of Unix, critical to the support of its design philosophy, which encourages the development of filters.
Concurrent processes are necessary for the development of filters. Whether they are implemented using fork, or some other primitive such as spawn, is surely an implementation detail? --DavidHopwood 18:26, 5 April 2007 (UTC)
[edit] Mythos
What about deleting that paragraph? I'm not sure whether the author was aware of the fact that he described the infamous "forkbomb" which has its own article and is already linked below. Further "mythos" is never actually explained. Also I doubt this is the right place for "honorable mentions" of fork() or whatever else. There would be no end if you did this for all articles. If at all, the article about the Matrix should link to fork but not vice-versa. Anyway, I remove it from the article. --82.141.49.144 03:55, 4 December 2005 (UTC)
- While I agree with much of this, rather than saying mythos, I think that "geek culture" is probably a bit better, as the term has seeped into "pop" culture. McKay 00:07, 9 December 2005 (UTC)
[edit] Make code compileable
I can't compile the code. Someone could add the propriate header files. It invite readers to experiment with fork(). The line with the /* Note */ should be changed and the note should be removed. I have no clue what the author meant with that. --Bernard François 14:58, 15 January 2006 (UTC)
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- From what I can see this code only needs the unistd.h (or stdlib.h if that doesn't work) header file, sometimes it also needs an extra include such as /sys/type.h or /sys/types.h, but this is sytem dependent. Also, the code should be in a main function. I'm not going to change the code on the page because it is only sample code. Regarding the /* Note... */, this line uses _exit(), which is different from exit(), (it has no underscore). These things may be effectively the same (actually they probably are - an exit() works fine here), but you'd need to see the source code for each of them. --Pyrofysh 06:36, 25 April 2006 (UTC)
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- But why did the author use _exit() instead of exit() at all in the child? --84.188.202.21 14:31, 12 October 2006 (UTC)
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- The standard library does some clean-ups with library call exit() (flushes buffers, closes file descriptors). Also, any files created with tmpfile() are closed, and some other things may occur also that one would prefer not to happen until the parent exits. The system call _exit() unconditionally exits. In addition, had vfork() been used instead of fork(), very unexpected things can happen because the memory is shared, if exit() is called before an exec; but sensible people don't use vfork. Agarvin 20:03, 12 November 2006 (UTC)
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[edit] SMP
Forks fully utilize SMP, right?321
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- If you mean Symmetric MultiProcessing, this depends more on the operating system's implementation of process handling than on the fork call. All fork does in most implementations is make a copy of a current process. --Pyrofysh 06:41, 25 April 2006 (UTC)
[edit] Clean code
Why is there a declaration of "int i" at the start of the code when it is only used in one of the for loops? Why not declare int i & j at the start, and forget about "i" at the beginning? Consistency? Maybe I am missing something?
- Nope, not missing anything - this is fixed. Steeltoe 05:13, 19 April 2006 (UTC)
- On that note, some compilers will not compile the code unless all variables are intialised at some point in the function. Currently i is only initialised under the "else if(pid <0)" condition, and j is only intialised under the "if(pid==0)" condition. As neither of these variables will be initialised under all cases, those compilers will cause an error. Ideally both int i and j should be declared at the start, because c intialises ints on declaration (even if it sometimes is to nonsense).
- I'm just putting this note here in case someone doesn't understand why their code doesn't compile - I think that the current code should remain unchanged regarding this because it is simpler having variables declared where they are used (in this case), additionally, most modern compilers don't suffer from this problem. --Pyrofysh 10:22, 7 June 2006 (UTC)
[edit] exit()
I've created an article for the inverse operation, exit. - Loadmaster 16:36, 18 August 2006 (UTC)
