1SD_PID_GET_SESSION(3) sd_pid_get_session SD_PID_GET_SESSION(3)
2
6 sd_pid_get_session, sd_pid_get_unit, sd_pid_get_user_unit,
7 sd_pid_get_owner_uid, sd_pid_get_machine_name, sd_pid_get_slice,
8 sd_peer_get_session, sd_peer_get_unit, sd_peer_get_user_unit,
9 sd_peer_get_owner_uid, sd_peer_get_machine_name, sd_peer_get_slice -
10 Determine session, service, owner of a session, container/VM or slice
11 of a specific PID or socket peer
12
14 #include <systemd/sd-login.h>
15 int sd_pid_get_session(pid_t pid, char **session);
17 int sd_pid_get_unit(pid_t pid, char **unit);
19 int sd_pid_get_user_unit(pid_t pid, char **unit);
21 int sd_pid_get_owner_uid(pid_t pid, uid_t *uid);
23 int sd_pid_get_machine_name(pid_t pid, char **name);
25 int sd_pid_get_slice(pid_t pid, char **slice);
27 int sd_peer_get_session(int fd, char **session);
29 int sd_peer_get_unit(int fd, char **unit);
31 int sd_peer_get_user_unit(int fd, char **unit);
33 int sd_peer_get_owner_uid(int fd, uid_t *uid);
35 int sd_peer_get_machine_name(int fd, char **name);
37 int sd_peer_get_slice(int fd, char **slice);
39
41 sd_pid_get_session() may be used to determine the login session
42 identifier of a process identified by the specified process identifier.
43 The session identifier is a short string, suitable for usage in file
44 system paths. Note that not all processes are part of a login session
45 (e.g. system service processes, user processes that are shared between
46 multiple sessions of the same user, or kernel threads). For processes
47 not being part of a login session this function will fail. The returned
48 string needs to be freed with the libc free(3) call after use.
49 sd_pid_get_unit() may be used to determine the systemd system unit
51 (i.e. system service) identifier of a process identified by the
52 specified PID. The unit name is a short string, suitable for usage in
53 file system paths. Note that not all processes are part of a system
54 unit/service (e.g. user processes, or kernel threads). For processes
55 not being part of a systemd system unit this function will fail. (More
56 specifically: this call will not work for processes that are part of
57 user units, use sd_pid_get_user_unit() for that.) The returned string
58 needs to be freed with the libc free(3) call after use.
59 sd_pid_get_user_unit() may be used to determine the systemd user unit
61 (i.e. user service) identifier of a process identified by the specified
62 PID. This is similar to sd_pid_get_unit() but applies to user units
63 instead of system units.
64 sd_pid_get_owner_uid() may be used to determine the Unix user
66 identifier of the owner of the session of a process identified the
67 specified PID. Note that this function will succeed for user processes
68 which are shared between multiple login sessions of the same user,
69 where sd_pid_get_session() will fail. For processes not being part of a
70 login session and not being a shared process of a user this function
71 will fail.
72 sd_pid_get_machine_name() may be used to determine the name of the VM
74 or container is a member of. The machine name is a short string,
75 suitable for usage in file system paths. The returned string needs to
76 be freed with the libc free(3) call after use.
77 sd_pid_get_slice() may be used to determine the slice unit the process
79 is a member of. See systemd.slice(5) for details about slices. The
80 returned string needs to be freed with the libc free(3) call after use.
81 If the pid parameter of any of these functions is passed as 0, the
83 operation is executed for the calling process.
84 The sd_peer_get_session(), sd_peer_get_unit(), sd_peer_get_user_unit(),
86 sd_peer_get_owner_uid(), sd_peer_get_machine_name() and
87 sd_peer_get_slice() calls operate similar to their PID counterparts,
88 but operate on a connected AF_UNIX socket and retrieve information
89 about the connected peer process.
90
92 On success, these calls return 0 or a positive integer. On failure,
93 these calls return a negative errno-style error code.
94
96 The sd_pid_get_session(), sd_pid_get_unit(), sd_pid_get_user_unit(),
97 sd_pid_get_owner_uid(), sd_pid_get_machine_name(), sd_pid_get_slice(),
98 sd_peer_get_session(), sd_peer_get_unit(), sd_peer_get_user_unit(),
99 sd_peer_get_owner_uid(), sd_peer_get_machine_name() and
100 sd_peer_get_slice() interfaces are available as a shared library, which
101 can be compiled and linked to with the libsystemd pkg-config(1) file.
102 Note that the login session identifier as returned by
104 sd_pid_get_session() is completely unrelated to the process session
105 identifier as returned by getsid(2).
106
108 systemd(1), sd-login(3), sd_session_is_active(3), getsid(2),
109 systemd.slice(5), systemd-machined.service(8)
110systemd 219 SD_PID_GET_SESSION(3)