install: allow specifiers in WantedBy/RequiredBy/Alias

This allows one templated unit to refer to another templated unit
at installation time.

Examples:

> grep WantedBy ~/.config/systemd/user/mpop@.timer
WantedBy=services@%i.target

> srv disable mpop@iit.timer
rm '/home/alxchk/.config/systemd/user/services@iit.target.wants/mpop@iit.timer'
> srv enable mpop@iit.timer
ln -s '/home/alxchk/.config/systemd/user/mpop@.timer' '/home/alxchk/.config/systemd/user/services@iit.target.wants/mpop@iit.timer'

Based-on-patch-by: Oleksii Shevchuk <alxchk@gmail.com>

1 files changed, 95 insertions, 0 deletions

diff --git a/src/shared/install-printf.c b/src/shared/install-printf.c
new file mode 100644
index 0000000000..85aebc42cc
--- /dev/null
+++ b/src/shared/install-printf.c
@@ -0,0 +1,95 @@
+/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
+
+/***
+  This file is part of systemd.
+
+  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
+  the Free Software Foundation; either version 2.1 of the License, or
+  (at your option) any later version.
+
+  systemd is distributed in the hope that it will be useful, but
+  WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+  Lesser General Public License for more details.
+
+  You should have received a copy of the GNU Lesser General Public License
+  along with systemd; If not, see <http://www.gnu.org/licenses/>.
+***/
+
+#include <assert.h>
+#include <stdlib.h>
+
+#include "specifier.h"
+#include "unit-name.h"
+#include "install-printf.h"
+
+static char *specifier_prefix_and_instance(char specifier, void *data, void *userdata) {
+        InstallInfo *i = userdata;
+        assert(i);
+
+        return unit_name_to_prefix_and_instance(i->name);
+}
+
+static char *specifier_prefix(char specifier, void *data, void *userdata) {
+        InstallInfo *i = userdata;
+        assert(i);
+
+        return unit_name_to_prefix(i->name);
+}
+
+static char *specifier_instance(char specifier, void *data, void *userdata) {
+        InstallInfo *i = userdata;
+        char *instance;
+        int r;
+
+        assert(i);
+
+        r = unit_name_to_instance(i->name, &instance);
+        if (r < 0)
+                return NULL;
+        if (instance != NULL)
+                return instance;
+        else
+                return strdup("");
+}
+
+char *install_full_printf(InstallInfo *i, const char *format) {
+
+        /* This is similar to unit_full_printf() but does not support
+         * anything path-related.
+         *
+         * %n: the full id of the unit                 (foo@bar.waldo)
+         * %N: the id of the unit without the suffix   (foo@bar)
+         * %p: the prefix                              (foo)
+         * %i: the instance                            (bar)
+
+         * %U the UID of the configured user or running user
+         * %u the username of the configured user or running user
+         * %m the machine ID of the running system
+         * %H the host name of the running system
+         * %b the boot ID of the running system
+         */
+
+        const Specifier table[] = {
+                { 'n', specifier_string,              i->name },
+                { 'N', specifier_prefix_and_instance, NULL },
+                { 'p', specifier_prefix,              NULL },
+                { 'i', specifier_instance,            NULL },
+
+//                { 'U', specifier_user_name,           NULL },
+//                { 'u', specifier_user_name,           NULL },
+
+                { 'm', specifier_machine_id,          NULL },
+                { 'H', specifier_host_name,           NULL },
+                { 'b', specifier_boot_id,             NULL },
+                { 0, NULL, NULL }
+        };
+
+        assert(i);
+        assert(format);
+
+        return specifier_printf(format, table, i);
+}