?? system()

1
???????????(2)

• ??????
• ???
• ??????????
• ???????
• ?? system()

???????
?????????????????
2
????????

• ????????????????? ?
• "?????"????????????????
• "?????"? ?CON? (?????) ??
• ?????????????????????
• ????? ? 0lt ???????? lt ??????
• ????? ? 1gt ???????? gt ??????
• ???????? ? 2gt ??????
• ????? ?gtgt????????2gtgt??????

3
?????????(1)
foo.txt ???

• Z\nyumon2gtdir gt foo.txt
• Z\nyumon2gtdir /f 2gt err.txt
• Z\nyumon2gtmore lt foo.txt
• Z\nyumon2gtmore lt err.txt

err.txt ? ?????
foo.txt ? ?????
foo.txt ? ????
Z\nyumon2gtdir /w gtgt foo.txt Z\nyumon2gtdir /v
2gtgt err.txt Z\nyumon2gtmore lt foo.txt Z\nyumon2gtm
ore lt err.txt
err.txt ??? ?????
foo.txt ? ??????
4
?????????(2)

• Z\nyumon2gtdir gt con
• Z\nyumon2gtdir /f 2gt con
• Z\nyumon2gtmore lt con gt goo.txt
• abcdefghijklmnopqrstuvwxyzltEntergt
• Ctrl-zltEntergt
• Z\nyumon2gtmore lt goo.txt

????????
????? ??? goo.txt ???
???????? ????? (???p.139 ??14.3)
??????Z\nyumon2\hello ???
Z\nyumon2\hellogthello gt hello.txt Z\nyumon2\hell
ogtmore lt hello.txt
5
?????

• ???????????????????????????????
• ????????????
• ????????????????????????

?????????
Z\nyumon1gtdir /s /b sort more
????/????
????/????
????
6
?????????????

• more ????????
• sort ????
• find ?????
• Z\nyumon1gtdir /s find "hello"
• findstr ????????
• Z\nyumon1gtfindstr /s "fopen" .c

help ???????????
7
???????

• notepad (???)
• Z\nyumon2\hellogtnotepad hello.c
• write (??????)
• Z\nyumon2\hellogtwrite
• Z\nyumon2\hellogtwrite hello.c
• devenv (????)
• Z\nyumon2\hellogtdevenv hello.c

?????
8
????????????????

• hello.c ????? hello2.c ?????????
• ? CL ?????????????(cl hello2.c)

/ hello world program 2 / include
ltstdio.hgt int main(void) printf("hello
world!\n") fprintf(stderr,"error
message!\n") return 0
??????
fprintf ????????(???p.130) stderr ???????
9
???????????????????

• ????????????????
• Z\nyumon2\hellogthello2
• ???
• Z\nyumon2\hellogtmore lt hello2.txt
• Z\nyumon2\hellogtmore lt err2.txt

Z\nyumon2\hellogthello2 gt hello2.txt Z\nyumon2\he
llogthello2 2gt err2.txt
Z\nyumon2\hellogthello2 gthello2.txt 2gterr2.txt
10
??????????????????

• ????????? typ.c ????????????????
• (???????????1?)

CL ??????????
/ typ.c stdin type / include ltstdio.hgt int
main(void) int c while
((cfgetc(stdin)) ! EOF) fputc(c,stdout)
return 0
stdin ????c ?1?????
?????????????
stdout ?1????
fgetc() ??????1???? fputc() ?????1????
stdin ???? EOF ??????
11
??????????????

• Z\nyumon2gttyp lt typ.c
• ...
• Z\nyumon2gttyp
• abc...
• abc...
• 123...
• 123...
• Z
• Z\nyumon2gtdir typ

type ????? more ????? ????????
???p.139 ??14.3??
????????? ?????????? Ctrl-c ?????
Ctrl-z ???
12
???????

• ????????????????????????
• (????????????2?)
• main(void) ? main(int argc, char argv )
• int argc ??????????
• char argv ???????????
• ?

Z\nyumon2gtmainarg 1.2345 abcde
!"'() argc4 argv0"mainarg" argv1"1.2345
" argv2"abcde" argv3"!'()"
13
????????????

• mainarg.c ??????????????

/ mainarg.c main argument test / include
ltstdio.hgt int main(int argc, char argv)
int i printf("argc d\n", argc) for (i
0 i lt argc i) printf("argvd
\"s\"\n", i, argvi) return 0
??????? (???p.180)
14
?? system( )

• ?? system( ) ??????????????????????????????????
• stdlib.h ??????

hello3.c
/ hello world program 3 / include
ltstdio.hgt include ltstdlib.hgt int main(void)
system("cls") printf("hello world!\n")
return 0
hello.c ? ??????
??????
cls ???? ??????
15
????? 2
??? p.180 ?A.2

• \" 2???? \' ?????
• \t ???? \\ ????(?????????)

hello4.c
/ hello world program 4 / include
ltstdio.hgt include ltsyslib.hgt int main(void)
system("cls") printf("\\\'hello world!\'\n")
return 0
???????
16
Office???????????

• Excel ???????(Excel.exe)???????????????????????

/ Excel exec program / include
ltstdio.hgt include ltstdlib.hgt int main(void)
system("\"C\\Program Files\\"
"Microsoft Office\\" "Office11\\Excel.exe
\"") return 0
excel2.c
???????????????????????????
??????????????? ??????????(\")????
Word(Winword.exe) ? PowerPoint(Powerpnt.exe)
??????????????
17
?????????????????????????????

• ????????????????????? chc.c ???????

/ chc.c char counter / include ltstdio.hgt int
main(int argc, char argv) int c, cnt0
while ((cfgetc(stdin)) ! EOF) if (
) printf(" ",
) return 0
18
??????? chc ????
argc 2 argv0 "chc" argv1 "i lt chc.c"
chc ????????? ????

• Z\nyumon2gtchc i lt chc.c
• i 10
• Z\nyumon2gtchc abc lt chc.c
• a 6

argc 2 argv0 "chc" argv1 "abc lt chc.c"
????????? ?????????? Ctrl-c ?????
19
????????? (??????)

• excel2.c ???????????????????
• ??(excel3.c)
• ??????????????
• excel ??????? argv1 ???
• strcat ?????
• excel ??????????????
• argc 1 ?????????
• ?????????system?????