Store MAC Address in char []

[martin910]

Hi,

I would like to know a way by which I can store the host address in char array.

For example,
//packet contains eth_header, ip_header, udp_header and data.

struct ethhdr *ethernet_header;
ethernet_header=(struct ethhdr*)(packet);

Hence, the source MAC can be retrieved from 'ethernet_header->h_source' but i would like to store to in hex format in a char []. Suggest a possible solution.

Thanks

[gerard4143]

If you know where its store and its length = size then its just a matter of copying it over to your character array ch[size]...byte by byte...Gerard4143

[martin910]

Consider the following case,

unsigned char *host_address;
'host_address' does point to an address.

on execution of the following snippet:

for(int i=0;i<6;i++){
printf("%.2x ",*host_address);
host_address++;
}

the output displayed is: 00 11 25 b7 20 23

Now I want this output to be stored in char *s, such that when i perform
printf("%s", variable_name);
Required Output should be:001125b72023

Probable solution may implement sprintf() method.
Please help!!

[gerard4143]

you have a space in your printf formatted string......"%.2x ".....it should be "%.2x"

#include <stdio.h>
#include <stdlib.h>

char *mystr = "gerard\n";

int main(int argc, char**argv)
{
	int i;
	for(i = 0;i < 5; i++)
	{
		printf("%.2x",*mystr);
		++mystr;
	}
	exit(EXIT_SUCCESS);
}

[martin910]

ok Gerard but my question is still not answered.

How do you store it HEX equivalents in char *s, such that they can be displayed on,

printf("%s",variable_name);

Please let me know in case I am not able put forward my query clearly.

[gerard4143]

quickly.....this will send the values to a file.....the rest you can figure out...Gerard4143

#include <stdio.h>
#include <stdlib.h>

char *mystr = "gerard\n";

int main(int argc, char**argv)
{
	FILE *fd;
	if (!(fd = fopen("gerard", "w")))
	{
		fputs("could not open gerard!\n", stderr);
		exit(EXIT_FAILURE);
	}

	int i;
	for(i = 0;i < 5; i++)
	{
		printf("%.2x",*mystr);
		fprintf(fd, "%.2x",*mystr);
		++mystr;
	}

	fclose(fd);
	exit(EXIT_SUCCESS);
}

[martin910]

Thanks....
What about the usage of sprintf? Can that be done?