NAME | SYNOPSIS | DESCRIPTION | RETURN VALUE | NOTES | SEE ALSO | COLOPHON

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

       The sd_id128_to_string() and sd_id128_from_string() interfaces are
       available 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

       This page is part of the systemd (systemd system and service manager)
       project.  Information about the project can be found at 
       ⟨http://www.freedesktop.org/wiki/Software/systemd⟩.  If you have a bug
       report for this manual page, see 
       ⟨http://www.freedesktop.org/wiki/Software/systemd/#bugreports⟩.  This
       page was obtained from the project's upstream Git repository 
       ⟨https://github.com/systemd/systemd.git⟩ on 2016-09-01.  If you dis‐
       cover any rendering problems in this HTML version of the page, or you
       believe there is a better or more up-to-date source for the page, or
       you have corrections or improvements to the information in this
       COLOPHON (which is not part of the original manual page), send a mail
       to man-pages@man7.org

systemd 231                                            SD_ID128_TO_STRING(3)