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:
void main (int argc, char * argv [], char * envp []);
$ a.out a1 a2 a3
main a.out
argc = 4 / * * /
argv [0] = "a.out"
argv [1] = "a1"
argv [2] = "a2"
argv [3] = "a3"
argv [4] = NULL
, argc argv . argc argv.
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# Include <stdio.h>
int main (int argc, char * argv [])
{printf("The name of this program is '% s'. \ N", argv [0]);
printf ("This program was invoked with% d arguments. \ n ", argc-1);
/ * ? * /
If (argc> 1)
{int i;
printf ("The arguments are: \ n");.
for (i = 1; i <argc; + + i)
printf ("% s \ n", argv [i]);}
return 0;}
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int main (int argc, char * argv [], char * envp []);
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# Include <stdio.h>
extern char ** environ;
int main (int argc, char * argv [])
{char ** var;
for (var = environ; * var! = NULL; + + var)
printf (" % s \ n ", * var);
return 0;}
getenv() putenv().
# Include <stdlib.h>
char * getenv (const char * name)
int putenv (const char * string)
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