bool tty_is_vc_resolve(const char *tty) { _cleanup_free_ char *active = NULL; assert(tty); if (startswith(tty, "/dev/")) tty += 5; if (streq(tty, "console")) { tty = resolve_dev_console(&active); if (!tty) return false; } return tty_is_vc(tty); }
int vt_disallocate(const char *name) { int fd, r; unsigned u; /* Deallocate the VT if possible. If not possible * (i.e. because it is the active one), at least clear it * entirely (including the scrollback buffer) */ if (!startswith(name, "/dev/")) return -EINVAL; if (!tty_is_vc(name)) { /* So this is not a VT. I guess we cannot deallocate * it then. But let's at least clear the screen */ fd = open_terminal(name, O_RDWR|O_NOCTTY|O_CLOEXEC); if (fd < 0) return fd; loop_write(fd, "\033[r" /* clear scrolling region */ "\033[H" /* move home */ "\033[2J", /* clear screen */ 10, false); safe_close(fd); return 0; } if (!startswith(name, "/dev/tty")) return -EINVAL; r = safe_atou(name+8, &u); if (r < 0) return r; if (u <= 0) return -EINVAL; /* Try to deallocate */ fd = open_terminal("/dev/tty0", O_RDWR|O_NOCTTY|O_CLOEXEC|O_NONBLOCK); if (fd < 0) return fd; r = ioctl(fd, VT_DISALLOCATE, u); safe_close(fd); if (r >= 0) return 0; if (errno != EBUSY) return -errno; /* Couldn't deallocate, so let's clear it fully with * scrollback */ fd = open_terminal(name, O_RDWR|O_NOCTTY|O_CLOEXEC); if (fd < 0) return fd; loop_write(fd, "\033[r" /* clear scrolling region */ "\033[H" /* move home */ "\033[3J", /* clear screen including scrollback, requires Linux 2.6.40 */ 10, false); safe_close(fd); return 0; }
int main(int argc, char *argv[]) { static const char virtualization_consoles[] = "hvc0\0" "xvc0\0" "hvsi0\0"; int r = EXIT_SUCCESS; char *active; const char *j; if (argc > 1 && argc != 4) { log_error("This program takes three or no arguments."); return EXIT_FAILURE; } if (argc > 1) arg_dest = argv[1]; log_set_target(LOG_TARGET_SAFE); log_parse_environment(); log_open(); umask(0022); if (detect_container(NULL) > 0) { log_debug("Automatically adding console shell."); if (add_symlink("console-getty.service", "console-getty.service") < 0) r = EXIT_FAILURE; /* Don't add any further magic if we are in a container */ goto finish; } if (read_one_line_file("/sys/class/tty/console/active", &active) >= 0) { const char *tty; tty = strrchr(active, ' '); if (tty) tty ++; else tty = active; /* Automatically add in a serial getty on the kernel * console */ if (isempty(tty) || tty_is_vc(tty)) free(active); else { int k; /* We assume that gettys on virtual terminals are * started via manual configuration and do this magic * only for non-VC terminals. */ k = add_serial_getty(tty); free(active); if (k < 0) { r = EXIT_FAILURE; goto finish; } } } /* Automatically add in a serial getty on the first * virtualizer console */ NULSTR_FOREACH(j, virtualization_consoles) { char *p; int k; if (asprintf(&p, "/sys/class/tty/%s", j) < 0) { log_oom(); r = EXIT_FAILURE; goto finish; } k = access(p, F_OK); free(p); if (k < 0) continue; k = add_serial_getty(j); if (k < 0) { r = EXIT_FAILURE; goto finish; } }