man: document when the various sd-login.h calls return ENXIO

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Lennart Poettering 2015-04-29 21:45:45 +02:00
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commit 882f407f31
1 changed files with 46 additions and 11 deletions

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@ -148,9 +148,10 @@
not all processes are part of a login session (e.g. system service
processes, user processes that are shared between multiple
sessions of the same user, or kernel threads). For processes not
being part of a login session this function will fail. The
returned string needs to be freed with the libc
<citerefentry project='man-pages'><refentrytitle>free</refentrytitle><manvolnum>3</manvolnum></citerefentry>
being part of a login session this function will fail with
-ENXIO. The returned string needs to be freed with the libc
<citerefentry
project='man-pages'><refentrytitle>free</refentrytitle><manvolnum>3</manvolnum></citerefentry>
call after use.</para>
<para><function>sd_pid_get_unit()</function> may be used to
@ -159,11 +160,12 @@
short string, suitable for usage in file system paths. Note that
not all processes are part of a system unit/service (e.g. user
processes, or kernel threads). For processes not being part of a
systemd system unit this function will fail. (More specifically:
this call will not work for processes that are part of user units,
use <function>sd_pid_get_user_unit()</function> for that.) The
returned string needs to be freed with the libc
<citerefentry project='man-pages'><refentrytitle>free</refentrytitle><manvolnum>3</manvolnum></citerefentry>
systemd system unit this function will fail with -ENXIO (More
specifically: this call will not work for processes that are part
of user units, use <function>sd_pid_get_user_unit()</function> for
that.) The returned string needs to be freed with the libc
<citerefentry
project='man-pages'><refentrytitle>free</refentrytitle><manvolnum>3</manvolnum></citerefentry>
call after use.</para>
<para><function>sd_pid_get_user_unit()</function> may be used to
@ -179,14 +181,16 @@
login sessions of the same user, where
<function>sd_pid_get_session()</function> will fail. For processes
not being part of a login session and not being a shared process
of a user this function will fail.</para>
of a user this function will fail with -ENXIO.</para>
<para><function>sd_pid_get_machine_name()</function> may be used
to determine the name of the VM or container is a member of. The
machine name is a short string, suitable for usage in file system
paths. The returned string needs to be freed with the libc
<citerefentry project='man-pages'><refentrytitle>free</refentrytitle><manvolnum>3</manvolnum></citerefentry>
call after use.</para>
<citerefentry
project='man-pages'><refentrytitle>free</refentrytitle><manvolnum>3</manvolnum></citerefentry>
call after use. For processes not part of a VM or containers this
function fails with -ENXIO.</para>
<para><function>sd_pid_get_slice()</function> may be used to
determine the slice unit the process is a member of. See
@ -218,6 +222,37 @@
code.</para>
</refsect1>
<refsect1>
<title>Errors</title>
<para>Returned errors may indicate the following problems:</para>
<variablelist>
<varlistentry>
<term><constant>-ENXIO</constant></term>
<listitem><para>Given field is not specified for the described
process or peer.</para>
</listitem>
</varlistentry>
<varlistentry>
<term><constant>-ESRCH</constant></term>
<listitem><para>The specified PID does not refer to a running
process.</para>
</listitem>
</varlistentry>
<varlistentry>
<term><constant>-ENOMEM</constant></term>
<listitem><para>Memory allocation failed.</para></listitem>
</varlistentry>
</variablelist>
</refsect1>
<refsect1>
<title>Notes</title>