#define pi 3.142
void main()
{
float circum,r;
printf("entr radius");
scanf("%f",&f);
area=2*pi*r;
printf("circum of the circle is =%f",f);
}
We have to write another C program which takes a file as input and replaces the string "pi" with the defined value
Where ever define variable is there i should replace with the value defined by the user.
void is not a standard return type for main. Use one of the following:
int main(void)
int main(int argc, char *argv[])
You need to read the file, parse each line and see, if it's a macro definition and replace it. Something along the following lines:
int main(int argc, char *argv[]) {
/* assume: C file to be modified is 1st commandline parameter */
/* write the modified file to stdout */
FILE *fp = fopen(argv[ 1 ], "r");
if (fp) {
char line[ 256 ]; /* change it to something suitable */
while(fgets(line, sizeof line, fp) != NULL) {
if (strstr(line, "pi") != NULL) {
/* parse line, extract input value, change it */
}
else puts(line);
}
fclose(fp);
}
return 0;
}
Well I will try and guide you in the right direction without doing your homework for you...
In C, main should always return an int. To accept a file as input, you can specify it as a command line argument and read from argv[] or you can use keyboard input for your filename which it appears you already know how to do.
These 3 pages should contain all you will need to finish the task: