diff options
Diffstat (limited to 'man')
| -rw-r--r-- | man/sd-id128.xml | 153 |
1 files changed, 108 insertions, 45 deletions
diff --git a/man/sd-id128.xml b/man/sd-id128.xml index b6e50a559e..566cc2b595 100644 --- a/man/sd-id128.xml +++ b/man/sd-id128.xml @@ -40,6 +40,69 @@ <refsynopsisdiv> <funcsynopsis> <funcsynopsisinfo>#include <systemd/sd-id128.h></funcsynopsisinfo> + + <para> + <constant>SD_ID128_ALLF</constant> + </para> + <para> + <constant>SD_ID128_NULL</constant> + </para> + <para> + <constant>SD_ID128_CONST_STR(<replaceable>id</replaceable>)</constant> + </para> + <para> + <constant>SD_ID128_FORMAT_STR</constant> + </para> + <para> + <constant>SD_ID128_FORMAT_VAL(<replaceable>id</replaceable>)</constant> + </para> + <para> + <constant>SD_ID128_MAKE(<replaceable>v0</replaceable>, <replaceable>v1</replaceable>, <replaceable>v2</replaceable>, <replaceable>v3</replaceable>, <replaceable>v4</replaceable>, <replaceable>v5</replaceable>, <replaceable>v6</replaceable>, <replaceable>v7</replaceable>, <replaceable>v8</replaceable>, <replaceable>v9</replaceable>, <replaceable>vA</replaceable>, <replaceable>vB</replaceable>, <replaceable>vC</replaceable>, <replaceable>vD</replaceable>, <replaceable>vE</replaceable>, <replaceable>vF</replaceable>)</constant> + </para> + <para> + <constant>SD_ID128_MAKE_STR(<replaceable>v0</replaceable>, <replaceable>v1</replaceable>, <replaceable>v2</replaceable>, <replaceable>v3</replaceable>, <replaceable>v4</replaceable>, <replaceable>v5</replaceable>, <replaceable>v6</replaceable>, <replaceable>v7</replaceable>, <replaceable>v8</replaceable>, <replaceable>v9</replaceable>, <replaceable>vA</replaceable>, <replaceable>vB</replaceable>, <replaceable>vC</replaceable>, <replaceable>vD</replaceable>, <replaceable>vE</replaceable>, <replaceable>vF</replaceable>)</constant> + </para> + <para> + <constant>SD_ID128_MAKE_UUID_STR(<replaceable>v0</replaceable>, <replaceable>v1</replaceable>, <replaceable>v2</replaceable>, <replaceable>v3</replaceable>, <replaceable>v4</replaceable>, <replaceable>v5</replaceable>, <replaceable>v6</replaceable>, <replaceable>v7</replaceable>, <replaceable>v8</replaceable>, <replaceable>v9</replaceable>, <replaceable>vA</replaceable>, <replaceable>vB</replaceable>, <replaceable>vC</replaceable>, <replaceable>vD</replaceable>, <replaceable>vE</replaceable>, <replaceable>vF</replaceable>)</constant> + </para> + <para> + <constant>SD_ID128_UUID_FORMAT_STR</constant> + </para> + + <funcprototype> + <funcdef>int <function>sd_id128_equal</function></funcdef> + <paramdef>sd_id128_t <parameter>a</parameter></paramdef> + <paramdef>sd_id128_t <parameter>b</parameter></paramdef> + </funcprototype> + + <funcprototype> + <funcdef>int <function>sd_id128_is_null</function></funcdef> + <paramdef>sd_id128_t <parameter>id</parameter></paramdef> + </funcprototype> + + <funcprototype> + <funcdef>int <function>sd_id128_is_allf</function></funcdef> + <paramdef>sd_id128_t <parameter>id</parameter></paramdef> + </funcprototype> + + <funcprototype> + <funcdef>int <function>sd_id128_in_setv</function></funcdef> + <paramdef>sd_id128_t <parameter>id</parameter></paramdef> + <paramdef>va_list <parameter>ap</parameter></paramdef> + </funcprototype> + + <funcprototype> + <funcdef>int <function>sd_id128_in_set_sentinel</function></funcdef> + <paramdef>sd_id128_t <parameter>id</parameter></paramdef> + <paramdef>…</paramdef> + <paramdef><constant>SD_ID128_NULL</constant></paramdef> + </funcprototype> + + <funcprototype> + <funcdef>int <function>sd_id128_in_set</function></funcdef> + <paramdef>sd_id128_t <parameter>id</parameter></paramdef> + <paramdef>…</paramdef> + </funcprototype> </funcsynopsis> <cmdsynopsis> @@ -51,20 +114,13 @@ <refsect1> <title>Description</title> - <para><filename>sd-id128.h</filename> provides APIs to process and generate 128-bit ID values. The - 128-bit ID values processed and generated by these APIs are a generalization of OSF UUIDs as defined by - <ulink url="https://tools.ietf.org/html/rfc4122">RFC 4122</ulink> but use a simpler string format. These - functions impose no structure on the used IDs, much unlike OSF UUIDs or Microsoft GUIDs, but are mostly - compatible with those types of IDs. + <para><filename>sd-id128.h</filename> provides APIs to generate, convert, and compare 128-bit ID values. + The 128-bit ID values processed and generated by these APIs are a generalization of OSF UUIDs as defined + by <ulink url="https://tools.ietf.org/html/rfc4122">RFC 4122</ulink> but use a simpler string format. + These functions impose no structure on the used IDs, much unlike OSF UUIDs or Microsoft GUIDs, but are + mostly compatible with those types of IDs. </para> - <para>See - <citerefentry><refentrytitle>sd_id128_to_string</refentrytitle><manvolnum>3</manvolnum></citerefentry>, - <citerefentry><refentrytitle>sd_id128_randomize</refentrytitle><manvolnum>3</manvolnum></citerefentry> - and - <citerefentry><refentrytitle>sd_id128_get_machine</refentrytitle><manvolnum>3</manvolnum></citerefentry> - for more information about the implemented functions.</para> - <para>A 128-bit ID is implemented as the following union type:</para> @@ -73,30 +129,28 @@ uint64_t qwords[2]; } sd_id128_t;</programlisting> - <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 + <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 by value (as opposed to pass-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> + <para><function>SD_ID128_MAKE()</function> is used to write a constant ID in source code. A commonly used + idiom is to assign a name to an 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><constant>SD_ID128_NULL</constant> may be used to refer to the 128-bit ID consisting of only - <constant>NUL</constant> bytes (i.e. all bits off).</para> + <para><constant>SD_ID128_NULL</constant> defines an ID consisting of only <constant>NUL</constant> bytes + (i.e. all bits off).</para> - <para><constant>SD_ID128_ALLF</constant> may be used to refer to the 128-bit ID consisting of only - <constant>0xFF</constant> bytes (i.e. all bits on).</para> + <para><constant>SD_ID128_ALLF</constant> defines an ID consisting of only <constant>0xFF</constant> bytes + (i.e. all bits on).</para> - <para><function>SD_ID128_MAKE_STR()</function> is similar to <function>SD_ID128_MAKE()</function>, but creates a - <type>const char*</type> expression that can be conveniently used in message formats and such:</para> + <para><function>SD_ID128_MAKE_STR()</function> is similar to <function>SD_ID128_MAKE()</function>, but + creates a <type>const char*</type> expression that can be conveniently used in message formats and + such:</para> <programlisting>#include <stdio.h> #define SD_MESSAGE_COREDUMP_STR SD_ID128_MAKE_STR(fc,2e,22,bc,6e,e6,47,b6,b9,07,29,ab,34,a2,50,b1) @@ -105,18 +159,16 @@ int main(int argc, char **argv) { puts("Match for coredumps: MESSAGE_ID=" SD_MESSAGE_COREDUMP_STR); }</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> + <para><function>SD_ID128_CONST_STR()</function> converts constant IDs into constant strings for + output. The following example code will output the string "fc2e22bc6ee647b6b90729ab34a250b1":</para> <programlisting>int main(int argc, char *argv[]) { puts("Match for coredumps: %s", SD_ID128_CONST_STR(SD_MESSAGE_COREDUMP)); }</programlisting> - <para><constant>SD_ID128_FORMAT_STR</constant> 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> + <para><constant>SD_ID128_FORMAT_STR</constant> and <function>SD_ID128_FORMAT_VAL()</function> is used to + format an 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; @@ -136,7 +188,7 @@ int main(int argc, char **argv) { best to avoid UUIDs of other variants, in order to avoid unnecessary ambiguities. All 128-bit IDs generated by the sd-id128 APIs strictly conform to Variant 1 Version 4 UUIDs, as per RFC 4122.</para> - <para>Use <function>sd_id128_equal()</function> to compare two 128-bit IDs:</para> + <para><function>sd_id128_equal()</function> compares two 128-bit IDs:</para> <programlisting>int main(int argc, char *argv[]) { sd_id128_t a, b, c; @@ -148,18 +200,22 @@ int main(int argc, char **argv) { return 0; }</programlisting> - <para>Use <function>sd_id128_is_null()</function> to check if an 128-bit ID consists of only - <constant>NUL</constant> bytes:</para> + <para><function>sd_id128_is_null()</function> checks if an ID consists of only <constant>NUL</constant> + bytes:</para> <programlisting>assert(sd_id128_is_null(SD_ID128_NULL));</programlisting> - <para>Similarly, use <function>sd_id128_is_allf()</function> to check if an 128-bit ID consists of only + <para>Similarly, <function>sd_id128_is_allf()</function> checks if an ID consists of only <constant>0xFF</constant> bytes (all bits on):</para> <programlisting>assert(sd_id128_is_allf(SD_ID128_ALLF));</programlisting> - <para>For convenience, <function>sd_id128_in_set()</function> takes a list of IDs and - returns true if any are equal to the first argument:</para> + <para><function>sd_id128_in_set_sentinel()</function> takes a list of IDs and returns true if the first + argument is equal to any of the subsequent arguments. The argument list is terminated by an + <constant>SD_ID128_NULL</constant> sentinel, which must be present.</para> + + <para><function>sd_id128_in_set()</function> is a convenience function that takes a list of IDs and + returns true if the first argument is equal to any of the subsequent arguments:</para> <programlisting>int main(int argc, char *argv[]) { sd_id12_t a = SD_ID128_MAKE(ee,89,be,71,bd,6e,43,d6,91,e6,c5,5d,eb,03,02,07); @@ -175,18 +231,25 @@ int main(int argc, char **argv) { </programlisting> <para><function>sd_id128_in_set()</function> is defined as a macro over - <function>sd_id128_in_set_sentinel()</function>, adding the <constant>SD_ID128_NULL</constant> - sentinel. Since <function>sd_id128_in_set_sentinel()</function> uses <constant>SD_ID128_NULL</constant> - as the sentinel, <constant>SD_ID128_NULL</constant> cannot be otherwise placed in the argument list. - </para> + <function>sd_id128_in_set_sentinel()</function>, adding the <constant>SD_ID128_NULL</constant> sentinel + automatically. Since <function>sd_id128_in_set_sentinel()</function> uses + <constant>SD_ID128_NULL</constant> as the sentinel, <constant>SD_ID128_NULL</constant> cannot be + otherwise placed in the argument list.</para> <para><function>sd_id128_in_setv()</function> is similar to <function>sd_id128_in_set_sentinel()</function>, but takes a <structname>struct varargs</structname> argument.</para> - <para>Note that new, randomized IDs may be generated with + <para>New randomized IDs may be generated with <citerefentry><refentrytitle>systemd-id128</refentrytitle><manvolnum>1</manvolnum></citerefentry>'s <command>new</command> command.</para> + + <para>See + <citerefentry><refentrytitle>sd_id128_to_string</refentrytitle><manvolnum>3</manvolnum></citerefentry>, + <citerefentry><refentrytitle>sd_id128_randomize</refentrytitle><manvolnum>3</manvolnum></citerefentry> + and + <citerefentry><refentrytitle>sd_id128_get_machine</refentrytitle><manvolnum>3</manvolnum></citerefentry> + for information about other implemented functions.</para> </refsect1> <xi:include href="libsystemd-pkgconfig.xml" /> |