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Diffstat (limited to 'man/sd-id128.xml')
| -rw-r--r-- | man/sd-id128.xml | 271 |
1 files changed, 132 insertions, 139 deletions
diff --git a/man/sd-id128.xml b/man/sd-id128.xml index d9ebb9c68..ea7972055 100644 --- a/man/sd-id128.xml +++ b/man/sd-id128.xml @@ -1,6 +1,6 @@ <?xml version='1.0'?> <!--*-nxml-*--> <!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN" - "http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd"> + "http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd"> <!-- This file is part of systemd. @@ -22,152 +22,145 @@ --> <refentry id="sd-id128" - xmlns:xi="http://www.w3.org/2001/XInclude"> - - <refentryinfo> - <title>sd-id128</title> - <productname>systemd</productname> - - <authorgroup> - <author> - <contrib>Developer</contrib> - <firstname>Lennart</firstname> - <surname>Poettering</surname> - <email>lennart@poettering.net</email> - </author> - </authorgroup> - </refentryinfo> - - <refmeta> - <refentrytitle>sd-id128</refentrytitle> - <manvolnum>3</manvolnum> - </refmeta> - - <refnamediv> - <refname>sd-id128</refname> - <refname>sd_id128_t</refname> - <refname>SD_ID128_MAKE</refname> - <refname>SD_ID128_CONST_STR</refname> - <refname>SD_ID128_FORMAT_STR</refname> - <refname>SD_ID128_FORMAT_VAL</refname> - <refname>sd_id128_equal</refname> - <refpurpose>APIs for processing 128-bit IDs</refpurpose> - </refnamediv> - - <refsynopsisdiv> - <funcsynopsis> - <funcsynopsisinfo>#include <systemd/sd-id128.h></funcsynopsisinfo> - </funcsynopsis> - - <cmdsynopsis> - <command>pkg-config --cflags --libs libsystemd</command> - </cmdsynopsis> - - </refsynopsisdiv> - - <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 fully 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> - - <programlisting>typedef union sd_id128 { - uint8_t bytes[16]; - uint64_t qwords[2]; + xmlns:xi="http://www.w3.org/2001/XInclude"> + + <refentryinfo> + <title>sd-id128</title> + <productname>systemd</productname> + + <authorgroup> + <author> + <contrib>Developer</contrib> + <firstname>Lennart</firstname> + <surname>Poettering</surname> + <email>lennart@poettering.net</email> + </author> + </authorgroup> + </refentryinfo> + + <refmeta> + <refentrytitle>sd-id128</refentrytitle> + <manvolnum>3</manvolnum> + </refmeta> + + <refnamediv> + <refname>sd-id128</refname> + <refname>sd_id128_t</refname> + <refname>SD_ID128_MAKE</refname> + <refname>SD_ID128_CONST_STR</refname> + <refname>SD_ID128_FORMAT_STR</refname> + <refname>SD_ID128_FORMAT_VAL</refname> + <refname>sd_id128_equal</refname> + <refpurpose>APIs for processing 128-bit IDs</refpurpose> + </refnamediv> + + <refsynopsisdiv> + <funcsynopsis> + <funcsynopsisinfo>#include <systemd/sd-id128.h></funcsynopsisinfo> + </funcsynopsis> + + <cmdsynopsis> + <command>pkg-config --cflags --libs libsystemd</command> + </cmdsynopsis> + + </refsynopsisdiv> + + <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 fully 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> + + <programlisting>typedef union sd_id128 { + uint8_t bytes[16]; + 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 - 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)); + <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; + <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; }</programlisting> - <para>Use <function>sd_id128_equal()</function> to compare two 128-bit IDs:</para> + <para>Use <function>sd_id128_equal()</function> to compare two 128-bit IDs:</para> - <programlisting>int main(int argc, char *argv[]) { - sd_id128_t a, b, c; - a = SD_ID128_MAKE(ee,89,be,71,bd,6e,43,d6,91,e6,c5,5d,eb,03,02,07); - b = SD_ID128_MAKE(f2,28,88,9c,5f,09,44,15,9d,d7,04,77,58,cb,e7,3e); - c = a; - assert(sd_id128_equal(a, c)); - assert(!sd_id128_equal(a, b)); - return 0; + <programlisting>int main(int argc, char *argv[]) { + sd_id128_t a, b, c; + a = SD_ID128_MAKE(ee,89,be,71,bd,6e,43,d6,91,e6,c5,5d,eb,03,02,07); + b = SD_ID128_MAKE(f2,28,88,9c,5f,09,44,15,9d,d7,04,77,58,cb,e7,3e); + c = a; + assert(sd_id128_equal(a, c)); + assert(!sd_id128_equal(a, b)); + return 0; }</programlisting> - <para>Note that new, randomized IDs may be generated - with - <citerefentry><refentrytitle>journalctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>'s - <option>--new-id</option> option.</para> - </refsect1> - - <xi:include href="libsystemd-pkgconfig.xml" /> - - <refsect1> - <title>See Also</title> - <para> - <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>, - <citerefentry><refentrytitle>sd_id128_to_string</refentrytitle><manvolnum>3</manvolnum></citerefentry>, - <citerefentry><refentrytitle>sd_id128_randomize</refentrytitle><manvolnum>3</manvolnum></citerefentry>, - <citerefentry><refentrytitle>sd_id128_get_machine</refentrytitle><manvolnum>3</manvolnum></citerefentry>, - <citerefentry project='man-pages'><refentrytitle>printf</refentrytitle><manvolnum>3</manvolnum></citerefentry>, - <citerefentry><refentrytitle>journalctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>, - <citerefentry><refentrytitle>sd-journal</refentrytitle><manvolnum>7</manvolnum></citerefentry>, - <citerefentry project='die-net'><refentrytitle>pkg-config</refentrytitle><manvolnum>1</manvolnum></citerefentry>, - <citerefentry><refentrytitle>machine-id</refentrytitle><manvolnum>5</manvolnum></citerefentry> - </para> - </refsect1> + <para>Note that new, randomized IDs may be generated with + <citerefentry><refentrytitle>journalctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>'s + <option>--new-id</option> option.</para> + </refsect1> + + <xi:include href="libsystemd-pkgconfig.xml" /> + + <refsect1> + <title>See Also</title> + <para> + <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>, + <citerefentry><refentrytitle>sd_id128_to_string</refentrytitle><manvolnum>3</manvolnum></citerefentry>, + <citerefentry><refentrytitle>sd_id128_randomize</refentrytitle><manvolnum>3</manvolnum></citerefentry>, + <citerefentry><refentrytitle>sd_id128_get_machine</refentrytitle><manvolnum>3</manvolnum></citerefentry>, + <citerefentry project='man-pages'><refentrytitle>printf</refentrytitle><manvolnum>3</manvolnum></citerefentry>, + <citerefentry><refentrytitle>journalctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>, + <citerefentry><refentrytitle>sd-journal</refentrytitle><manvolnum>7</manvolnum></citerefentry>, + <citerefentry project='die-net'><refentrytitle>pkg-config</refentrytitle><manvolnum>1</manvolnum></citerefentry>, + <citerefentry><refentrytitle>machine-id</refentrytitle><manvolnum>5</manvolnum></citerefentry> + </para> + </refsect1> </refentry> |