sd_id128_to_string(3) — Linux manual page


SD_ID128_TO_STRING(3)      sd_id128_to_string      SD_ID128_TO_STRING(3)

NAME         top

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

SYNOPSIS         top

       #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         top

       sd_id128_to_string() formats a 128-bit ID as a 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 a 128-bit ID returned in ret. Alternatively, this call can
       also parse a 37-character string with a 128-bit ID formatted as
       RFC UUID. If ret is passed as NULL the function will validate the
       passed ID string, but not actually return it in parsed form.

       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 endianness.

       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         top

       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         top

       These APIs are implemented as a shared library, which can be
       compiled and linked to with the libsystemd pkg-config(1) file.

SEE ALSO         top

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

COLOPHON         top

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systemd 248                                        SD_ID128_TO_STRING(3)

Pages that refer to this page: sd_bus_set_address(3)sd-id128(3)systemd.directives(7)systemd.index(7)