man fmt_ip6c (3): write a formatted ASCII representation of an IPv6 number

SYNTAX

#include <ip6.h>

unsigned int fmt_ip6c(char *dest,const char ip[16]);

fmt_ip6c formats an IPv6 number in ASCII representation from ip and writes the result into dest. It returns the number of bytes written.

fmt_ip6c will apply "::" compression to the output.

If ip is an IPv4-mapped IPv6 address, fmt_ip6c will output it as IPv4 address.

If dest equals FMT_LEN (i.e. is zero), fmt_ip6c returns the number of bytes it would have written.

fmt_ip6c does not append \0.

For convenience, ip6.h defines the integer IP6_FMT to be big enough to contain every possible fmt_ip6c output plus \0.

#include <ip6.h>

  char buf[IP6_FMT];
  char ip[16];
  buf[fmt_ip6c(buf,ip)]=0;