- <para>This union type allows accessing the 128 bit ID
- as 16 separate bytes or 2 64 bit words. It is generally
- safer to access the ID components by their 8 bit array
- to avoid endianess issues. This union is intended to
- be passed call-by-value (as opposed to
- call-by-reference) and may be directly manipulated by
- clients.</para>
-
- <para>A couple of macros are defined to denote and
- decode 128 bit IDs:</para>
-
- <para><function>SD_ID128_MAKE()</function> may be used
- to write a 128 bit ID in source code. A commonly used
- idiom is to give 128 bit IDs names using this macro:</para>
-
- <programlisting>#define SD_MESSAGE_COREDUMP SD_ID128_MAKE(fc,2e,22,bc,6e,e6,47,b6,b9,07,29,ab,34,a2,50,b1)</programlisting>
-
- <para><function>SD_ID128_FORMAT_STR</function> and
- <function>SD_ID128_FORMAT_VAL()</function> may be used
- to format a 128 bit ID in a
- <citerefentry><refentrytitle>printf</refentrytitle><manvolnum>3</manvolnum></citerefentry>
- format string, as shown in the following
- example:</para>
-
- <programlisting>int main(int argc, char *argv[]) {
- sd_id128_t id;
- id = SD_ID128_MAKE(ee,89,be,71,bd,6e,43,d6,91,e6,c5,5d,eb,03,02,07);
- printf("The ID encoded in this C file is " SD_ID128_FORMAT_STR ".\n", SD_ID128_FORMAT_VAL(id));
- return 0;
+ <para>This union type allows accessing the 128-bit ID as 16
+ separate bytes or two 64-bit words. It is generally safer to
+ access the ID components by their 8-bit array to avoid endianness
+ issues. This union is intended to be passed call-by-value (as
+ opposed to call-by-reference) and may be directly manipulated by
+ clients.</para>
+
+ <para>A couple of macros are defined to denote and decode 128-bit
+ IDs:</para>
+
+ <para><function>SD_ID128_MAKE()</function> may be used to denote a
+ constant 128-bit ID in source code. A commonly used idiom is to
+ assign a name to a 128-bit ID using this macro:</para>
+
+ <programlisting>#define SD_MESSAGE_COREDUMP SD_ID128_MAKE(fc,2e,22,bc,6e,e6,47,b6,b9,07,29,ab,34,a2,50,b1)</programlisting>
+
+ <para><function>SD_ID128_CONST_STR()</function> may be used to
+ convert constant 128-bit IDs into constant strings for output. The
+ following example code will output the string
+ "fc2e22bc6ee647b6b90729ab34a250b1":</para>
+ <programlisting>int main(int argc, char *argv[]) {
+ puts(SD_ID128_CONST_STR(SD_MESSAGE_COREDUMP));
+}</programlisting>
+
+ <para><function>SD_ID128_FORMAT_STR</function> and
+ <function>SD_ID128_FORMAT_VAL()</function> may be used to format a
+ 128-bit ID in a
+ <citerefentry project='man-pages'><refentrytitle>printf</refentrytitle><manvolnum>3</manvolnum></citerefentry>
+ format string, as shown in the following example:</para>
+
+ <programlisting>int main(int argc, char *argv[]) {
+ sd_id128_t id;
+ id = SD_ID128_MAKE(ee,89,be,71,bd,6e,43,d6,91,e6,c5,5d,eb,03,02,07);
+ printf("The ID encoded in this C file is " SD_ID128_FORMAT_STR ".\n", SD_ID128_FORMAT_VAL(id));
+ return 0;