Unix????????

1
Unix????????
???
2
Unix??

• 1965??ARPA????MIT???????????????????????????,???
  ???????????????????????MULTICS (MULTiplexed
  Information and Computing Service )

• MULTICS?????
• ?????????????????????????
• ???????????????????????????????????

3
Unix??

• MULTICS????????????,??????????????,1969?4????????,
  ????????????,MIT????,MULTICS????,???????(????????
  ????????)??MULTICS?????????????????(???????2000?10
  ?30?1708)

• MULTICS????????????????????,???????????UNIX???????
  ???

4
Unix??

• ?????????Unix???
• 1969?,?????MULTICS?????,Ken Thompson?Dennis M.
  Ritchie ???????DEC PDP-7?,???????MULTICS?????????
  ???
• ????????PDP-7?????,?????????????????????,?????????
  ????shell ?????
• 1970?,??????,????????MULTICS??????UNIX
• 1973?,UNIX?C??????,??,UNIX???
• 1977?,Unix????????????PDP-7??

5
Unix??

• UNIX???????????Unix?????????????????????????????.

• ??UNIX???????
• ??,??UNIX??C????,????????,UNIX???????????????PC???
  ???????????????
• ??,?????????,???????????
• ??,????????,??????????????????????????

6
Unix???

• 1983????
• 1999?????????

Ken Thompson Dennis
Ritchie
7
Unix???
8
????
9
?????????
10
??
./copy pan.c haiwei.c vi copy.c
(Shell)
fork()
exec(vi)
????????????,???????,?????????????????????????
11
??
./copy pan.c haiwei.c vi copy.c
(Shell)
fork()
exec(vi)
???????????????,???????,???????????????,??????
12
??
./copy pan.c haiwei.c vi copy.c
(Shell)
fork()
exec(vi)
????????????????,namei(/usr/bin/vi)?????????
13
??
./copy pan.c haiwei.c vi copy.c
(Shell)
fork()
exec(vi)
??????????????
14
??
(Shell???)
???
???
??
copy.c
???
???
??
vi
15
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(Shell???)
???
???
??
???
???
??
copy.c
vi????
16
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vi-1????
U?-1
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???I
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vi-1

vi
???
???
??
U?
vi????
17
??
./copy pan.c haiwei.c vi copy.c
(Shell)
fork()
exec(vi)
18
??
./copy pan.c haiwei.c vi copy.c
?????
namei(copy.c)
pan.c

copy.c
???????
?
?
open()
19
??
./copy pan.c haiwei.c vi copy.c
?????
namei(copy.c)
pan.c

copy.c
???????
?
?
open()
20
??
./copy pan.c haiwei.c vi copy.c
?????
???
???? ????
pan.c


pan.c
Wei.c
Copy.c
hai.c
Pan.c

copy.c
?
?
vi
pan.c
copy.c
namei()
vi-1
pan.c
vi-2
21
??
./copy pan.c haiwei.c vi copy.c

• include ltfcntl.hgt
• char buffer 1024
• int main(int argc, char argv)
• int fdold, fdnew, count
• fdoldopen(argv1, O_RDONLY)
• fdnewcreat(argv2, 0666)
• while((count read(fdold, buffer,
  sizeof(buffer)))gt0)
• write(fdnew, buffer, count)

22
??
gcc o copy copy.c ./copy pan.c haiwei.c

• include ltfcntl.hgt
• char buffer 1024
• int main(int argc, char argv)
• int fdold, fdnew, count
• fdoldopen(argv1, O_RDONLY)
• fdnewcreat(argv2, 0666)
• while((count read(fdold, buffer,
  sizeof(buffer)))gt0)
• write(fdnew, buffer, count)

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