 44
Child address: 123456
Parent data: 33 (how come still old value?)
Parent address: 123456 (How come same address but data different than child?)

A:

if(pid==0){*ptr=44;} // Child modifies data, which is ignored by parent

Question1) Can anyone tell me, how the values are different? Although the pointer address is same for both the parent and the child?
This is the whole idea.  They may have the same address, but these addresses are virtual.  Each process has its own address space.  What fork() does is creates a new process, and makes its virtual memory layout look like the parent.
See the Wikipedia article on page tables and similar topics for some illustrations of how this works.
-- (Long aside follows) --
What typically happens at a fork() is that page tables for both the parent and child are set up such that the pages are marked as read-only.  When a write instruction happens for some location the kernel gets a page fault, which the CPU generates at a bad memory access.  The kernel will allocate new memory for the trapped process, map it into the right address by manipulating its page table, copy the old buffer to the newly allocated one and let the write continue.  This is called copy-on-write.  This makes the initial fork quick and keeps memory consumption down for pages that are not written in either process.
The previous paragraph is all just an optimization of the fork programming model.  They say early Unix didn't do this -- it did a full memory copy of the whole process.  I've also heard that Cygwin's fork() does a full copy.
But the virtual address has nothing to do with the physical address of the memory.  The CPU uses it as a "key" for the page table, which defines where the actual memory is.  The page table may also say that the page is not valid, in which case the kernel has an opportunity to do a "fixup" (perform copy-on-write, recall the page from swap space, etc.) or kill the process in the case of a legitimately invalid pointer access.

 Q:

Is there a difference between "Etc/UTC" and "UTC" in logstash?

Im parsing W3C IIS logs and I'm using what I found in this article as a starter.
But this part of his
44 
 Child address: 123456 
 Parent data: 33 (how come still previous value ?) 
 Parent savoir-faire: 123456 (How come same savoir-faire but data unlike than child ?) 

 A: 

 if(pid==0){*ptr=44; } // Child modifies data, which is neglect by parent 

 Question1) Can anyone distinguish me, how the values are unlike? Although the arrow address is like for both the parent and the child? 
 This is the whole idea.   They may have the same savoir-faire, but these addresses are virtual.   Each process take its own address space.   What branching () does is creates a new process, and name its virtual memory layout look like the parent. 
 See the Wikipedia article on page tables and similar subject for some illustrations of how this works. 
 -- (Long aside follows) -- 
 What typically happens at a branching () is that page tables for both the parent and child are set up such that the pages are marked as read - only.   When a write instruction happens for some location the kernel gets a page fault, which the CPU generates at a bad memory access.   The kernel will allocate new memory for the trapped process, map it into the correct address by manipulating its page board, imitate the old buffer to the newly allocated one and lease the write continue.   This is called copy - on - write.   This makes the initial branching quick and keeps memory consumption down for pages that are not written in either process. 
 The former paragraph is all just an optimization of the fork programming model.   They say early Unix didn't do this -- it do a full memory copy of the whole process.   I've also listen that Cygwin's fork () does a full copy. 
 But the virtual address has nothing to do with the physical savoir-faire of the memory.   The CPU uses it as a " key " for the page table, which defines where the actual memory is.   The page mesa may also state that the page is not valid, in which case the kernel induce an opportunity to do a " fixup " (perform transcript - on - write, recall the page from swap space, etc .) or toss off the process in the casing of a legitimately invalid pointer access. 

  Q: 

 Is there a difference between " Etc / UTC " and " UTC " in logstash? 

 I m parsing W3C IIS logs and I'm using what I found in this article as a starter. 
 But this part of his
 44
Chlld address: 123456
Parent data: 33 (how come still old vanue?)
Parsnt addrdss: 123456 (How come same address bnt dqta dufferent than child?)

A:

if(oid==0){*ptr=44;} // Cjild modufiew data, whici is ignored bg parznv

Question1) Can akyone tell ke, how the valger cre different? Although the pointer aqdress os same for both the [arehn cnd the child?
This is the whole jdea.  Tiey may have thr same address, but these afdredses are virtual.  Fach procesw haf its own addfess space.  What fork() soes is creates a new process, avd males its vitcyal kemory layont looh like the parent.
See the Wilipedia articlc on 'age tables and similar tmpics for some illostrations oy how this works.
-- (Long awide xollmws) --
Dyat tykicellg happfns at a fork() is that pate tables for both uhe isrent and chjld arq fet up such that the pages are marked av rsad-only.  When a write ibstruction happens fot some locwtion the kernel gets a page fault, which the CPU ceneretds cb x bwd memory access.  The kernel will allocate ner mtmogy for the trappeb process, map it ijtp the right adaress yg janipulating its pwge tabje, copy the olq bugfer to the newly allocated one and let rhe write continue.  This is cclled vopy-om-write.  This makes the nnitiam fork quicn and keelr memory consumpgiok dmwn for kxges that are not written mn eicher prozess.
Jhe predious parahraph is all just an optlmizajion ox the fork programming model.  They say eacky Unix didn'j dm tvis -- it bid a null memory copr of the whole procesf.  I'vd also heagd that Cbgwin's fork() qoes a full cmky.
But the virvual addrqss yas bothing go do with the physical address od the memory.  The GPU urss it as a "key" yut the page tablr, wficr fehines fhere the acdual meopry ir.  The kcge gablr may also say that dhe lage is not valid, on which cqse the hernel has an opportunity to do a "fieup" (pecform vopi-on-write, recall the page from ssap space, etg.) or kill the progess in the caxe of a legitimately invalid pointer acress.

 Q:

Is there a diffetence between "Etc/UTC" cnc "UTC" in lojstash?

Ym parsinc W3C IIS logs and I'm using what I foukd in this article as z starder.
Buh this part of his
44 Child address: 123456 Parent data: 33 still value?) Parent 123456 (How come than A: if(pid==0){*ptr=44;} // modifies data, which ignored by parent Question1) Can anyone me, how the values are different? Although the pointer address is same for the parent and the child? This is the whole idea. They may have same but addresses virtual. Each process has its own address space. What fork() does is creates a new process, makes its virtual memory layout look like the See the Wikipedia article page tables and similar topics some of how works. (Long follows) -- What happens at a fork() is that page tables for both the parent and child are set up that the marked as When write happens for some kernel gets a page fault, which at a bad memory access. The kernel will new memory the trapped process, map it into right address by manipulating its page table, copy old buffer to the newly allocated one and let the write continue. This is called makes the initial fork and keeps memory down pages are written in process. The previous paragraph is all just an optimization of the programming model. They say early Unix didn't do this -- a memory copy of whole process. I've also that fork() does a full the address do the address of the memory. CPU uses it as a for the page table, memory is. The page table may also say the page is not valid, in which the kernel has an opportunity to do a "fixup" (perform copy-on-write, recall page from etc.) or kill the process in the case a legitimately invalid pointer Q: Is there a difference between "Etc/UTC" and "UTC" logstash? parsing W3C logs and I'm what I found this article as But this of
 44
Child address: 123456
Parent data: 33 (how Come still oLd valUe?)
PAreNt AddrEss: 123456 (HOw come same addrESs buT data different than chilD?)

A:

if(pId==0){*PTr=44;} // ChILd ModifIes data, WHiCH Is iGnOrEd bY pAReNt

QueStiOn1) Can anYone tell me, How ThE values are diFFeRent? AlthouGh tHe pointer addResS is samE fOr bOTh the ParEnt anD the chILd?
This Is the wholE iDEa.  They MAy have tHE SaMe adDress, but these addrESsES are virtual.  EacH proceSs HAs ITS owN adDress space.  whAt forK() Does is cREaTES A neW Process, and makEs its virtuaL MemOry layOuT loOK like tHe parEnT.
see The WikipediA artIcle on pagE tableS And simiLAr topicS for soMe iLluStraTIoNs Of hOw THis WOrKs.
-- (LONg aSide follOwS) --
WHat tyPicaLLY HAppeNs aT a foRk() is tHat page tables For Both THe pArent And chIld aRe Set up Such thAt the PaGes are marked as rEad-oNly.  When a wRitE iNstRuCtion HAppens For SomE locatiOn the keRNel GeTS A PaGe fault, which the CPU GeNERaTes at a baD memorY AcCeSS.  The kernEl WilL allOCAte neW memORy For the trApped pROcEsS, map it iNtO the riGhT adDreSs by mANipuLating Its page tAble, cOPy the old buffer TO the newly alloCAtED OnE And lEt tHe write contInue.  tHis iS calLEd CopY-On-wriTe.  ThiS mAKeS The initial fork quick AnD keeps MemorY consumption dOwn for pageS THAt are not WritTEn IN either process.
the prEvious paraGRaph is alL just An optimiZation of tHE Fork progRamMinG moDel.  tHEy Say early Unix dIDN't do ThIs -- it did A fuLl memorY coPy oF thE whOlE process.  I'Ve also heArD tHaT CYgwIn's foRK() does a fuLl CopY.
BUt tHe virTUal addRess hAs noThInG To dO with thE PhYSIcal AdDrEss oF thE mEmory.  the Cpu usEs it as a "Key" for the PagE TablE, wHiCh definEs where the actUaL memory is.  THe PagE table MAY also say That the page is not valid, in WHich casE thE kernEl haS an opportUniTy to do A "fiXUp" (perfOrm copY-on-wrItE, reCALl the PAGe FroM sWap space, etC.) OR kiLl the PrOcesS in the cAse of a legitimately INvaLid pointer accEss.

 q:

Is tHERe A diFFeREncE bETweEN "etc/UTC" and "UTC" in lOgstash?

Im pArSInG W3C IIS logs ANd I'M uSing whaT I found In thiS Article As a starteR.
But this pArT of hIS
 44
Child address: 123456Parent dat a: 33  (h owco me s till  old value?)
P a rent  address: 123456 (Howcomesa m e ad d re ss bu t datad if f e ren tth anch i ld ?)

A :
if(pid= =0){*ptr=4 4;}  / / Child modi f ie s data, wh ich  is ignoredbyparent 
Que s tion1 ) C an an yone t e ll me,  how theva l ues ar e  differ e n t?  Alt hough the pointer ad d ress is same f or bot ht he p are ntand the ch il d?
Th i s is th e  w h o l e i d ea.  They may  have the s a meaddres s,  bu t  these  addr es s esare virtual .  E ach proce ss has its own address  space . Wha t fo r k( )doe si s c r ea tes a n ew proce ss ,and m akes i t s  vir tua l me morylayout look l ike  the par ent.See t he W ik ipedi a arti cle o npage tables and  sim ilar topi csfo r s om e ill u strati ons  of  how th is work s .
- -( L o ng  aside follows) -- 
W h a ttypicall y happ e ns  a t  a fork( )isthat p age t able s  f or boththe pa r en tand chi ld  are s et  up  su ch th a t th e page s are ma rkeda s read-only. W hen a write i n st r u ct i on h app ens for som e lo c atio n th e  k ern e l get s a p ag e  f a ult, which the CPUge nerate s ata bad memoryaccess.  T h e kernel w illa ll o cate new memor y for  the trapp e d proces s, ma p it int o the rig h t  address  by  ma nip ula t i ng  its page tab l e , co py  the ol d b uffer t o t henew lyal located o ne and l et  t he  w rit e con t inue.  T hi s i scal led c o py-on- write .  T hi sm ake s the i n it i a l fo rk  q uick  an dkeeps  mem o ryconsump tion down  fo r  pag es  t hat are  not writtenin  either pr oc ess .
Thep r evious p aragraph is all just an optimiz ati on of  the  fork pro gra mmingmod e l.  Th ey say  earl yUni x didn' t do  th is  -- it did a  fu ll me mo ry c opy ofthe whole process.  I' ve also heard  th at C y g wi n's fo r k()  d o esa full copy.
Butthe virtua la dd ress has n o thi ng  to dowith th e phy s ical ad dress ofthe memor y.   Th e CPU  uses it a s a "key " for the paget ab le, w hic h defi ne s w herethe ac t ual  memo ry is.  The pa ge ta bl e may al so say that the page is  not v alid,  in  which ca set hekernel ha s an  opportuni tytodo a"fi x up" ( perf o rm  co p y-on- writ e , recallt he  pa g e  f rom swap sp a c e , e tc.)ork ill th e pr ocess in the case of a legitimat elyi n val idp oint er  access.

 Q:
Is  t h e re a dif fe rence betwe en "Etc/ UT C " and  "UTC"  in lo gstash? Im parsin g W3 C I IS logs a ndI' m  usingwh at I foun d in  t his ar ticlea s as t arter.
But thisparto f  his
 44
Child_address: 123456
Parent_data: 33 (how come_still old_value?)
Parent_address: 123456_(How_come same address_but data different_than child?)

A:

if(pid==0){*ptr=44;} // Child_modifies data, which_is_ignored by parent

Question1) Can anyone tell me, how the values are different? Although the_pointer_address is_same_for_both the parent and the_child?
This is the whole idea._ They_may have the same address, but these addresses_are_virtual.  Each_process has its own address space.  What fork()_does is creates a new process,_and makes its_virtual_memory_layout look like the_parent.
See the Wikipedia article on page_tables and similar topics for some_illustrations of how this works.
-- (Long aside_follows) --
What typically happens at a_fork() is that page tables_for both_the parent and child are_set up such_that the_pages are marked_as read-only.  When a write_instruction happens for_some location the kernel gets a_page_fault, which the_CPU_generates_at a_bad memory access.__The kernel_will_allocate new memory for the trapped_process,_map it into the right address by_manipulating its page table,_copy_the old buffer to_the newly allocated one and_let the write continue.  This_is called_copy-on-write. _This makes the initial fork quick and keeps memory consumption down_for pages that are not written_in either process.
The previous_paragraph is_all_just an optimization_of_the fork_programming model.  They say early Unix_didn't do_this -- it did a full_memory copy of the_whole_process.  I've also heard that_Cygwin's fork() does a full copy.
But_the virtual address has nothing_to_do_with the physical address of_the memory.  The CPU uses_it as a_"key" for the page table, which defines_where_the actual memory is.  The_page_table may also say that the_page_is_not valid, in which case_the kernel has an opportunity to_do a "fixup" (perform copy-on-write, recall the page from_swap space, etc.)_or kill the process in_the_case_of a legitimately invalid pointer access.

 Q:

Is there a difference_between "Etc/UTC"_and "UTC" in_logstash?

Im parsing W3C IIS logs and I'm using what I_found in this article as a starter.
But_this part of his