trusty (3) sd_pid_get_machine_name.3.gz

NAME

       sd_pid_get_session, sd_pid_get_unit, sd_pid_get_user_unit, sd_pid_get_owner_uid, sd_pid_get_machine_name
       - Determine session, service, owner of a session or container/VM of a specific PID

SYNOPSIS

       #include <systemd/sd-login.h>

       int sd_pid_get_session(pid_t pid, char** session);

       int sd_pid_get_unit(pid_t pid, char** unit);

       int sd_pid_get_user_unit(pid_t pid, char** unit);

       int sd_pid_get_owner_uid(pid_t pid, uid_t* uid);

       int sd_pid_get_machine_name(pid_t pid, char** name);

DESCRIPTION

       sd_pid_get_session() may be used to determine the login session identifier of a process identified by the
       specified process identifier. The session identifier is a short string, suitable for usage in file system
       paths. Note that 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 free(3) call after use.

       sd_pid_get_unit() may be used to determine the systemd system unit (i.e. system service) identifier of a
       process identified by the specified PID. The unit name is a 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
       sd_pid_get_user_unit() for that.) The returned string needs to be freed with the libc free(3) call after
       use.

       sd_pid_get_user_unit() may be used to determine the systemd user unit (i.e. user service) identifier of a
       process identified by the specified PID. This is similar to sd_pid_get_unit() but applies to user units
       instead of system units.

       sd_pid_get_owner_uid() may be used to determine the Unix user identifier of the owner of the session of a
       process identified the specified PID. Note that this function will succeed for user processes which are
       shared between multiple login sessions of the same user, where sd_pid_get_session() will fail. For
       processes not being part of a login session and not being a shared process of a user this function will
       fail.

       sd_pid_machine_name() 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 free(3) call after use.

       If the pid parameter of any of these functions is passed as 0 the operation is executed for the calling
       process.

RETURN VALUE

       On success these calls return 0 or a positive integer. On failure, these calls return a negative
       errno-style error code.

NOTES

       The sd_pid_get_session(), sd_pid_get_unit(), sd_pid_get_user_unit(), sd_pid_get_owner_uid() and
       sd_pid_get_machine_name() interfaces are available as shared library, which can be compiled and linked to
       with the libsystemd-loginpkg-config(1) file.

       Note that the login session identifier as returned by sd_pid_get_session() is completely unrelated to the
       process session identifier as returned by getsid(2).

SEE ALSO

       systemd(1), sd-login(3), sd_session_is_active(3), getsid(2)