trusty (3) sd_id128_from_string.3.gz

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, 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 string with 32
       hexadecimal digits (either lowercase or uppercase, terminated by NUL) and parses them back into an 128
       bit ID returned in ret. Alternatively, this call can also parse a 37 character string with a 128bit ID
       formatted as RFC UUID.

       For more information about the sd_id128_t type see sd-id128(3). Note that these calls operate the same
       way on all architectures, i.e. the results do not depend on endianess.

       When formatting a 128 bit ID into a string it is often easier to use a format string for printf(3). This
       is easily 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-id128pkg-config(1) file.

SEE ALSO

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