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#include <netinet/ether.h>
#include <stdio.h>
#include <sys/mman.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <stdlib.h>
/* glibc 2.4 has no ETHER_FILE_NAME, host compile fails without this */
#ifndef ETHER_FILE_NAME
#define ETHER_FILE_NAME "/etc/ethers"
#endif
#define ETHER_LINE_LEN 256
/* This test requires /etc/ethers to exist
* and to have nonzero length. You should create it manually,
* if it doesn't exist.
*/
int main(void)
{
struct ether_addr addr;
char hostname[ETHER_LINE_LEN];
int fd, i;
const char *ethers;
struct stat statb;
if ((fd = open(ETHER_FILE_NAME, O_RDONLY)) == -1) {
perror ("Cannot open file /etc/ethers");
exit(1);
}
if (fstat(fd, &statb)) {
perror("Stat failed");
exit(1);
}
ethers = mmap(NULL, statb.st_size, PROT_READ, MAP_SHARED, fd, 0);
if (ethers == MAP_FAILED) {
perror("File mapping failed");
exit(1);
}
ether_line(ethers, &addr, hostname);
for (i = 0; i < 6; i++) {
printf("%02x", addr.ether_addr_octet[i]);
if (i < 5)
printf(":");
}
printf(" %s\n", hostname);
return 0;
}
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