unit: printf specifiers %u and %h: $USER and $HOME.

These printf specifiers allow us to refer to $HOME and $USER
in unit files. These are particularly helpful in instanced
units that have "User=" set, and in systemd --user domains.

The specifiers will return the pw_name and pw_dir fields
if the unit file has a User= field.

If the unit file does not have a User= field, the value
substituted is either $USER or $HOME from the environment,
or, if unset, the values from pw_name or pw_dir.

This patch is somewhat after Ran Benita's original patch,
which didn't get merged. I've split up the 2 specifiers
and extended them to do what is logically expected from
these specifiers.

Note that expansion is done at `start` time, not after
the units are parsed. Using `systemctl show` will just
show the specifiers.
This commit is contained in:
Auke Kok 2012-07-13 22:28:43 -07:00 committed by Lennart Poettering
parent 7c5f152aca
commit b2896c905b
2 changed files with 56 additions and 0 deletions

View File

@ -258,6 +258,16 @@
<entry>Runtime socket dir</entry>
<entry>This is either /run (for the system manager) or $XDG_RUNTIME_DIR (for user managers).</entry>
</row>
<row>
<entry><literal>%u</literal></entry>
<entry>User name</entry>
<entry>This is the name of the configured user of the unit, or (if none is set) the user running the systemd instance.</entry>
</row>
<row>
<entry><literal>%h</literal></entry>
<entry>User home directory</entry>
<entry>This is the home directory of the configured user of the unit, or (if none is set) the user running the systemd instance.</entry>
</row>
</tbody>
</tgroup>
</table>

View File

@ -2221,6 +2221,48 @@ static char *specifier_runtime(char specifier, void *data, void *userdata) {
return strdup("/run");
}
static char *specifier_user_name(char specifier, void *data, void *userdata) {
Service *s = userdata;
int r;
const char *username;
/* get USER env from our own env if set */
if (!s->exec_context.user)
return getusername_malloc();
/* fish username from passwd */
username = s->exec_context.user;
r = get_user_creds(&username, NULL, NULL, NULL);
if (r < 0)
return NULL;
return strdup(username);
}
static char *specifier_user_home(char specifier, void *data, void *userdata) {
Service *s = userdata;
int r;
const char *username, *home;
/* return HOME if set, otherwise from passwd */
if (!s->exec_context.user) {
char *h;
r = get_home_dir(&h);
if (r < 0)
return NULL;
return h;
}
username = s->exec_context.user;
r = get_user_creds(&username, NULL, NULL, &home);
if (r < 0)
return NULL;
return strdup(home);
}
char *unit_name_printf(Unit *u, const char* format) {
/*
@ -2256,6 +2298,8 @@ char *unit_full_printf(Unit *u, const char *format) {
* %r root cgroup path of this systemd instance (e.g. "/user/lennart/shared/systemd-4711")
* %R parent of root cgroup path (e.g. "/usr/lennart/shared")
* %t the runtime directory to place sockets in (e.g. "/run" or $XDG_RUNTIME_DIR)
* %u the username of the configured User or running user
* %h the homedir of the configured User or running user
*/
const Specifier table[] = {
@ -2270,6 +2314,8 @@ char *unit_full_printf(Unit *u, const char *format) {
{ 'r', specifier_cgroup_root, NULL },
{ 'R', specifier_cgroup_root, NULL },
{ 't', specifier_runtime, NULL },
{ 'u', specifier_user_name, NULL },
{ 'h', specifier_user_home, NULL },
{ 0, NULL, NULL }
};