delta: if prefix is specified, only show overrides there

systemd-delta /run/systemd/system will show all unit overrides
in /run, etc.

2 files changed, 109 insertions, 42 deletions

diff --git a/man/systemd-delta.xml b/man/systemd-delta.xml
index 413ebd8de8..4d3ab78040 100644
--- a/man/systemd-delta.xml
+++ b/man/systemd-delta.xml
@@ -49,7 +49,9 @@
 
         <refsynopsisdiv>
                 <cmdsynopsis>
-                        <command>systemd-delta <arg choice="opt" rep="repeat">OPTIONS</arg> <arg choice="opt" rep="repeat">SUFFIX</arg></command>
+                        <command>systemd-delta</command>
+			<arg choice="opt" rep="repeat">OPTIONS</arg>
+			<arg choice="opt" rep="repeat"><replaceable>PREFIX</replaceable><optional>/<replaceable>SUFFIX</replaceable></optional>|<replaceable>SUFFIX</replaceable></arg>
                 </cmdsynopsis>
         </refsynopsisdiv>
 
@@ -57,18 +59,46 @@
                 <title>Description</title>
 
                 <para><command>systemd-delta</command> may be used to
-                identify and compare configuration files in
-                <filename>/etc</filename> that override default
-                counterparts in <filename>/usr</filename>. The command
-                line argument can be one or more name of a subdirectories of
-                <filename>/etc</filename> or
-                <filename>/usr/lib</filename> to compare, such as
-                <filename>tmpfiles.d</filename>, <filename>sysctl.d</filename> or
-                <filename>systemd/system</filename>.</para>
-
-                <para>When no argument is specified a number of
-                well-known subdirectories are searched for overridden
-                files.</para>
+                identify and compare configuration files that override
+                other configuration files. Files in
+                <filename>/etc</filename> have highest priority, files
+                in <filename>/run</filename> have the second highest
+                priority, ..., files in <filename>/lib</filename> have
+                lowest priority. Files in a directory with higher
+                priority override files with the same name in
+                directories of lower priority. In addition, certain
+                configuration files can have <literal>.d</literal>
+                directories which contain "drop-in" files with
+                configuration snippets which augment the main
+                configuration file. "Drop-in" files can be overriden
+                in the same way by placing files with the same name in
+                a directory of higher priority (except that in case of
+                "drop-in" files, both the "drop-in" file name and the
+                name of the containing directory, which corresponds to
+                the name of the main configuration file, must match).
+                For a fuller explanation, see
+                <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>.
+		</para>
+
+		<para>The command line argument will be split into a
+		prefix and a suffix. Either is optional. The prefix
+		must be one of the directories containing
+		configuration files (<filename>/etc</filename>,
+		<filename>/run</filename>,
+		<filename>/usr/lib</filename>, ...). If it is given,
+		only overriding files contained in this directory will
+		be shown. Otherwise, all overriding files will be
+		shown. The suffix must be a name of a subdirectory
+		containing configuration files like
+		<filename>tmpfiles.d</filename>,
+		<filename>sysctl.d</filename> or
+		<filename>systemd/system</filename>. If it is given,
+		only configuration files in this subdirectory (across
+		all configuration paths) will be analyzed. Otherwise,
+		all configuration files will be analyzed. If the
+		commandline argument is not given at all, all
+		configuration files will be analyzed. See below for
+		some examples.</para>
         </refsect1>
 
         <refsect1>
@@ -168,9 +198,28 @@
                         </varlistentry>
 
                 </variablelist>
-
         </refsect1>
 
+	<refsect1>
+		<title>Examples</title>
+
+		<para>To see all local configuration:</para>
+		<programlisting>systemd-delta
+		</programlisting>
+
+		<para>To see all runtime configuration:</para>
+		<programlisting>systemd-delta /run
+		</programlisting>
+
+		<para>To see all system unit configuration changes:</para>
+		<programlisting>systemd-delta systemd/system
+		</programlisting>
+
+		<para>To see all runtime "drop-in" changes for system units:</para>
+		<programlisting>systemd-delta --type=extended /run/systemd/system
+		</programlisting>
+	</refsect1>
+
         <refsect1>
                 <title>Exit status</title>
 
@@ -181,7 +230,8 @@
         <refsect1>
                 <title>See Also</title>
                 <para>
-                        <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>
+                        <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
+                        <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>
                 </para>
         </refsect1>
 
diff --git a/src/delta/delta.c b/src/delta/delta.c
index f049eb229a..19eaed3631 100644
--- a/src/delta/delta.c
+++ b/src/delta/delta.c
@@ -4,6 +4,7 @@
   This file is part of systemd.
 
   Copyright 2012 Lennart Poettering
+  Copyright 2013 Zbigniew Jędrzejewski-Szmek
 
   systemd is free software; you can redistribute it and/or modify it
   under the terms of the GNU Lesser General Public License as published by
@@ -346,7 +347,7 @@ static int enumerate_dir(Hashmap *top, Hashmap *bottom, Hashmap *drops, const ch
         }
 }
 
-static int process_suffix(const char *suffix) {
+static int process_suffix(const char *suffix, const char *onlyprefix) {
         const char *p;
         char *f;
         Hashmap *top, *bottom, *drops;
@@ -391,20 +392,23 @@ static int process_suffix(const char *suffix) {
                 o = hashmap_get(bottom, key);
                 assert(o);
 
-                if (path_equal(o, f))
-                        notify_override_unchanged(f);
-                else {
-                        k = found_override(f, o);
-                        if (k < 0)
-                                r = k;
-                        else
-                                n_found += k;
+                if (!onlyprefix || startswith(o, onlyprefix)) {
+                        if (path_equal(o, f)) {
+                                notify_override_unchanged(f);
+                        } else {
+                                k = found_override(f, o);
+                                if (k < 0)
+                                        r = k;
+                                else
+                                        n_found += k;
+                        }
                 }
 
                 h = hashmap_get(drops, key);
                 if (h)
                         HASHMAP_FOREACH(o, h, j)
-                                n_found += notify_override_extended(f, o);
+                                if (!onlyprefix || startswith(o, onlyprefix))
+                                        n_found += notify_override_extended(f, o);
         }
 
 finish:
@@ -423,24 +427,41 @@ finish:
         return r < 0 ? r : n_found;
 }
 
-static int process_suffix_chop(const char *suffix) {
+static int process_suffixes(const char *onlyprefix) {
+        const char *n;
+        int n_found = 0, r;
+
+        NULSTR_FOREACH(n, suffixes) {
+                r = process_suffix(n, onlyprefix);
+                if (r < 0)
+                        return r;
+                else
+                        n_found += r;
+        }
+        return n_found;
+}
+
+static int process_suffix_chop(const char *arg) {
         const char *p;
 
-        assert(suffix);
+        assert(arg);
 
-        if (!path_is_absolute(suffix))
-                return process_suffix(suffix);
+        if (!path_is_absolute(arg))
+                return process_suffix(arg, NULL);
 
         /* Strip prefix from the suffix */
         NULSTR_FOREACH(p, prefixes) {
-                if (startswith(suffix, p)) {
-                        suffix += strlen(p);
+                const char *suffix = startswith(arg, p);
+                if (suffix) {
                         suffix += strspn(suffix, "/");
-                        return process_suffix(suffix);
+                        if (*suffix)
+                                return process_suffix(suffix, NULL);
+                        else
+                                return process_suffixes(arg);
                 }
         }
 
-        log_error("Invalid suffix specification %s.", suffix);
+        log_error("Invalid suffix specification %s.", arg);
         return -EINVAL;
 }
 
@@ -595,15 +616,11 @@ int main(int argc, char *argv[]) {
                 }
 
         } else {
-                const char *n;
-
-                NULSTR_FOREACH(n, suffixes) {
-                        k = process_suffix(n);
-                        if (k < 0)
-                                r = k;
-                        else
-                                n_found += k;
-                }
+                k = process_suffixes(NULL);
+                if (k < 0)
+                        r = k;
+                else
+                        n_found += k;
         }
 
         if (r >= 0)