SD_ID128_TO_STRING(3)

NAME
sd_id128_to_string, sd_id128_from_string - Format or parse 128 bit IDs as strings

SYNOPSIS

#include <systemd/sd-id128.h>

char* sd_id128_to_string(sd_id128_t id, char s[33]);

int sd_id128_from_string(const char s[33], sd_id128_t* ret);

DESCRIPTION

sd_id128_to_string() formats a 128 bit ID as character string. It expects the ID and a string array capable of storing 33 characters. The ID will be formatted as 32 lowercase hexadecimal digits and be terminated by a NUL byte.

sd_id128_from_string() implements the reverse operation: it takes a 33 character array with 32 hexadecimial digits (terminated by NUL) and parses them back into an 128 bit ID returned in ret.

For more information about the sd_id128_t type see sd-id128(3).

When formatting a 128 bit ID into a string it is often easier to use a format string for printf(3). This is easly done using the SD_ID128_FORMAT_STR and SD_ID128_FORMAT_VAL() macros. For more information see sd-id128(3).

RETURN VALUE

sd_id128_to_string() always succeeds and returns a pointer to the string array passed in. sd_id128_from_string returns 0 on success (in which case ret is filled in), or a negative errno-style error code.

NOTES

The sd_id128_to_string() and sd_id128_from_string() interfaces are available as shared library, which can be compiled and linked to with the libsystemd-id128 pkg-config(1) file.

SEE ALSO

systemd(1), sd-id128(3), printf(3)