---
name: "ip6"
section: "3"
platform: "macos"
package: "ksh"
version: "42"
release: "macOS 26.5"
platforms: ["macos"]
url: "https://new.carta.tech/ip6"
---

# ip6(3)

IP V6 address support

## NAME

ip6 - IP V6 address support

## SYNOPSIS

```
#include <ip6.h>
char*      fmtip6(unsigned char* addr, int bits);
int        strtoip6(const char* str, char** end, unsigned char* addr, unsigned char* bits);
```

## DESCRIPTION

$1$2fmtip6()fmtip6()fmtip6()fmtip6()fmtip6()fmtip6()fmtip6()fmtip6() formats the IPV6 address $1$2addraddraddraddraddraddraddraddr with optional prefix bits $1$2bitsbitsbitsbitsbitsbitsbitsbits (0 if not a prefix) into a thread-specific 0-terminated temporary buffer and returns a pointer to the formatted value.

$1$2strtoip6()strtoip6()strtoip6()strtoip6()strtoip6()strtoip6()strtoip6()strtoip6() converts a formatted IPV6 address from the 0-terminated string $1$2strstrstrstrstrstrstrstr into a host order IPV6 address in $1$2addraddraddraddraddraddraddraddr which must be a buffer of at least $1$2IP6ADDRIP6ADDRIP6ADDRIP6ADDRIP6ADDRIP6ADDRIP6ADDRIP6ADDR bytes. If $1$2bitsbitsbitsbitsbitsbitsbitsbits is not 0 then an optional **/***bits* (prefix size in bits) is parsed and $1$2\*bits\*bits\*bits\*bits\*bits\*bits\*bits\*bits is set to the number of prefix bits. If $1$2endendendendendendendend is not 0 then $1$2\*end\*end\*end\*end\*end\*end\*end\*end will point to the first unparsed character in $1$2strstrstrstrstrstrstrstr on return. 0 is returned on success, -1 on failure.

## SEE ALSO

dss(1)