/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/ /*** This file is part of systemd. Copyright (C) 2014 David Herrmann <dh.herrmann@gmail.com> 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/>. ***/ /* * Stacked Terminal-Emulator * This is an interactive test of the term_screen implementation. It runs a * fully-fletched terminal-emulator inside of a parent TTY. That is, instead of * rendering the terminal as X11-window, it renders it as sub-window in the * parent TTY. Think of this like what "GNU-screen" does. */ #include <assert.h> #include <errno.h> #include <stdarg.h> #include <stdbool.h> #include <stdio.h> #include <stdlib.h> #include <string.h> #include <sys/ioctl.h> #include <termios.h> #include "macro.h" #include "pty.h" #include "ring.h" #include "sd-event.h" #include "term-internal.h" #include "util.h" typedef struct Output Output; typedef struct Terminal Terminal; struct Output { int fd; unsigned int width; unsigned int height; unsigned int in_width; unsigned int in_height; unsigned int cursor_x; unsigned int cursor_y; char obuf[4096]; size_t n_obuf; bool resized : 1; bool in_menu : 1; }; struct Terminal { sd_event *event; sd_event_source *frame_timer; Output *output; term_utf8 utf8; term_parser *parser; term_screen *screen; int in_fd; int out_fd; struct termios saved_in_attr; struct termios saved_out_attr; Pty *pty; Ring out_ring; bool is_scheduled : 1; bool is_dirty : 1; bool is_menu : 1; }; /* * Output Handling */ #define BORDER_HORIZ "\xe2\x94\x81" #define BORDER_VERT "\xe2\x94\x83" #define BORDER_VERT_RIGHT "\xe2\x94\xa3" #define BORDER_VERT_LEFT "\xe2\x94\xab" #define BORDER_DOWN_RIGHT "\xe2\x94\x8f" #define BORDER_DOWN_LEFT "\xe2\x94\x93" #define BORDER_UP_RIGHT "\xe2\x94\x97" #define BORDER_UP_LEFT "\xe2\x94\x9b" static int output_winch(Output *o) { struct winsize wsz = { }; int r; assert_return(o, -EINVAL); r = ioctl(o->fd, TIOCGWINSZ, &wsz); if (r < 0) { log_error("error: cannot read window-size: %m"); return -errno; } if (wsz.ws_col != o->width || wsz.ws_row != o->height) { o->width = wsz.ws_col; o->height = wsz.ws_row; o->in_width = MAX(o->width, 2U) - 2; o->in_height = MAX(o->height, 6U) - 6; o->resized = true; } return 0; } static int output_flush(Output *o) { ssize_t len; if (o->n_obuf < 1) return 0; len = loop_write(o->fd, o->obuf, o->n_obuf, false); if (len < 0) { log_error("error: cannot write to TTY (%zd): %s", len, strerror(-len)); return len; } o->n_obuf = 0; return 0; } static int output_write(Output *o, const void *buf, size_t size) { ssize_t len; int r; assert_return(o, -EINVAL); assert_return(buf || size < 1, -EINVAL); if (size < 1) return 0; if (o->n_obuf + size > o->n_obuf && o->n_obuf + size <= sizeof(o->obuf)) { memcpy(o->obuf + o->n_obuf, buf, size); o->n_obuf += size; return 0; } r = output_flush(o); if (r < 0) return r; len = loop_write(o->fd, buf, size, false); if (len < 0) { log_error("error: cannot write to TTY (%zd): %s", len, strerror(-len)); return len; } return 0; } _printf_(3,0) static int output_vnprintf(Output *o, size_t max, const char *format, va_list args) { char buf[4096]; int r; assert_return(o, -EINVAL); assert_return(format, -EINVAL); assert_return(max <= sizeof(buf), -EINVAL); r = vsnprintf(buf, max, format, args); if (r > (ssize_t)max) r = max; return output_write(o, buf, r); } _printf_(3,4) static int output_nprintf(Output *o, size_t max, const char *format, ...) { va_list args; int r; va_start(args, format); r = output_vnprintf(o, max, format, args); va_end(args); return r; } _printf_(2,0) static int output_vprintf(Output *o, const char *format, va_list args) { char buf[4096]; int r; assert_return(o, -EINVAL); assert_return(format, -EINVAL); r = vsnprintf(buf, sizeof(buf), format, args); assert_return(r < (ssize_t)sizeof(buf), -ENOBUFS); return output_write(o, buf, r); } _printf_(2,3) static int output_printf(Output *o, const char *format, ...) { va_list args; int r; va_start(args, format); r = output_vprintf(o, format, args); va_end(args); return r; } static int output_move_to(Output *o, unsigned int x, unsigned int y) { int r; assert_return(o, -EINVAL); /* force the \e[H code as o->cursor_x/y might be out-of-date */ r = output_printf(o, "\e[%u;%uH", y + 1, x + 1); if (r < 0) return r; o->cursor_x = x; o->cursor_y = y; return 0; } static int output_print_line(Output *o, size_t len) { const char line[] = BORDER_HORIZ BORDER_HORIZ BORDER_HORIZ BORDER_HORIZ BORDER_HORIZ BORDER_HORIZ BORDER_HORIZ BORDER_HORIZ BORDER_HORIZ BORDER_HORIZ BORDER_HORIZ BORDER_HORIZ BORDER_HORIZ BORDER_HORIZ BORDER_HORIZ BORDER_HORIZ BORDER_HORIZ BORDER_HORIZ BORDER_HORIZ BORDER_HORIZ BORDER_HORIZ BORDER_HORIZ BORDER_HORIZ BORDER_HORIZ BORDER_HORIZ BORDER_HORIZ BORDER_HORIZ BORDER_HORIZ BORDER_HORIZ BORDER_HORIZ BORDER_HORIZ BORDER_HORIZ BORDER_HORIZ BORDER_HORIZ BORDER_HORIZ BORDER_HORIZ BORDER_HORIZ BORDER_HORIZ BORDER_HORIZ BORDER_HORIZ BORDER_HORIZ BORDER_HORIZ BORDER_HORIZ BORDER_HORIZ BORDER_HORIZ BORDER_HORIZ BORDER_HORIZ BORDER_HORIZ BORDER_HORIZ BORDER_HORIZ BORDER_HORIZ BORDER_HORIZ BORDER_HORIZ BORDER_HORIZ BORDER_HORIZ BORDER_HORIZ BORDER_HORIZ BORDER_HORIZ BORDER_HORIZ BORDER_HORIZ BORDER_HORIZ BORDER_HORIZ BORDER_HORIZ BORDER_HORIZ; const size_t max = (sizeof(line) - 1) / (sizeof(BORDER_HORIZ) - 1); size_t i; int r = 0; assert_return(o, -EINVAL); for ( ; len > 0; len -= i) { i = (len > max) ? max : len; r = output_write(o, line, i * (sizeof(BORDER_HORIZ) - 1)); if (r < 0) break; } return r; } _printf_(2,3) static int output_frame_printl(Output *o, const char *format, ...) { va_list args; int r; assert(o); assert(format); /* out of frame? */ if (o->cursor_y < 3 || o->cursor_y >= o->height - 3) return 0; va_start(args, format); r = output_vnprintf(o, o->width - 2, format, args); va_end(args); if (r < 0) return r; return output_move_to(o, 1, o->cursor_y + 1); } static Output *output_free(Output *o) { if (!o) return NULL; /* disable alternate screen buffer */ output_printf(o, "\e[?1049l"); output_flush(o); /* o->fd is owned by the caller */ free(o); return NULL; } static int output_new(Output **out, int fd) { Output *o; int r; assert_return(out, -EINVAL); o = new0(Output, 1); if (!o) return log_oom(); o->fd = fd; r = output_winch(o); if (r < 0) goto error; /* enable alternate screen buffer */ r = output_printf(o, "\e[?1049h"); if (r < 0) goto error; r = output_flush(o); if (r < 0) goto error; *out = o; return 0; error: output_free(o); return r; } static void output_draw_frame(Output *o) { unsigned int i; assert(o); /* print header-frame */ output_printf(o, BORDER_DOWN_RIGHT); output_print_line(o, o->width - 2); output_printf(o, BORDER_DOWN_LEFT "\r\n" BORDER_VERT "\e[2;%uH" /* cursor-position: 2/x */ BORDER_VERT "\r\n" BORDER_VERT_RIGHT, o->width); output_print_line(o, o->width - 2); output_printf(o, BORDER_VERT_LEFT "\r\n"); /* print body-frame */ for (i = 0; i < o->in_height; ++i) { output_printf(o, BORDER_VERT "\e[%u;%uH" /* cursor-position: 2/x */ BORDER_VERT "\r\n", i + 4, o->width); } /* print footer-frame */ output_printf(o, BORDER_VERT_RIGHT); output_print_line(o, o->width - 2); output_printf(o, BORDER_VERT_LEFT "\r\n" BORDER_VERT "\e[%u;%uH" /* cursor-position: 2/x */ BORDER_VERT "\r\n" BORDER_UP_RIGHT, o->height - 1, o->width); output_print_line(o, o->width - 2); output_printf(o, BORDER_UP_LEFT); /* print header/footer text */ output_printf(o, "\e[2;3H"); output_nprintf(o, o->width - 4, "systemd - embedded terminal emulator"); output_printf(o, "\e[%u;3H", o->height - 1); output_nprintf(o, o->width - 4, "press ^C to enter menu"); } static void output_draw_menu(Output *o) { assert(o); output_frame_printl(o, "%s", ""); output_frame_printl(o, " Menu: (the following keys are recognized)"); output_frame_printl(o, " q: quit"); output_frame_printl(o, " ^C: send ^C to the PTY"); } static void output_draw_screen(Output *o, term_screen *s) { unsigned int i, j; bool first = true; assert(o); assert(s); for (j = 0; j < s->page->height && j < o->in_height; ++j) { if (!first) output_printf(o, "\e[m\r\n" BORDER_VERT); first = false; for (i = 0; i < s->page->width && i < o->in_width; ++i) { term_charbuf_t buf; term_cell *cell = &s->page->lines[j]->cells[i]; size_t k, len, ulen; const uint32_t *str; char utf8[4]; switch (cell->attr.fg.ccode) { case TERM_CCODE_DEFAULT: output_printf(o, "\e[39m"); break; case TERM_CCODE_256: output_printf(o, "\e[38;5;%um", cell->attr.fg.c256); break; case TERM_CCODE_RGB: output_printf(o, "\e[38;2;%u;%u;%um", cell->attr.fg.red, cell->attr.fg.green, cell->attr.fg.blue); break; case TERM_CCODE_BLACK ... TERM_CCODE_WHITE: if (cell->attr.bold) output_printf(o, "\e[%um", cell->attr.fg.ccode - TERM_CCODE_BLACK + 90); else output_printf(o, "\e[%um", cell->attr.fg.ccode - TERM_CCODE_BLACK + 30); break; case TERM_CCODE_LIGHT_BLACK ... TERM_CCODE_LIGHT_WHITE: output_printf(o, "\e[%um", cell->attr.fg.ccode - TERM_CCODE_LIGHT_BLACK + 90); break; } switch (cell->attr.bg.ccode) { case TERM_CCODE_DEFAULT: output_printf(o, "\e[49m"); break; case TERM_CCODE_256: output_printf(o, "\e[48;5;%um", cell->attr.bg.c256); break; case TERM_CCODE_RGB: output_printf(o, "\e[48;2;%u;%u;%um", cell->attr.bg.red, cell->attr.bg.green, cell->attr.bg.blue); break; case TERM_CCODE_BLACK ... TERM_CCODE_WHITE: output_printf(o, "\e[%um", cell->attr.bg.ccode - TERM_CCODE_BLACK + 40); break; case TERM_CCODE_LIGHT_BLACK ... TERM_CCODE_LIGHT_WHITE: output_printf(o, "\e[%um", cell->attr.bg.ccode - TERM_CCODE_LIGHT_BLACK + 100); break; } output_printf(o, "\e[%u;%u;%u;%u;%u;%um", cell->attr.bold ? 1 : 22, cell->attr.italic ? 3 : 23, cell->attr.underline ? 4 : 24, cell->attr.inverse ? 7 : 27, cell->attr.blink ? 5 : 25, cell->attr.hidden ? 8 : 28); str = term_char_resolve(cell->ch, &len, &buf); if (len < 1) { output_printf(o, " "); } else { for (k = 0; k < len; ++k) { ulen = term_utf8_encode(utf8, str[k]); output_write(o, utf8, ulen); } } } } output_move_to(o, s->cursor_x + 1, s->cursor_y + 3); output_printf(o, "\e[m"); } static void output_draw(Output *o, bool menu, term_screen *screen) { assert(o); /* * This renders the contenst of the terminal. The layout contains a * header, the main body and a footer. Around all areas we draw a * border. It looks something like this: * * +----------------------------------------------------+ * | Header | * +----------------------------------------------------+ * | | * | | * | | * | Body | * | | * | | * ~ ~ * ~ ~ * +----------------------------------------------------+ * | Footer | * +----------------------------------------------------+ * * The body is the part that grows vertically. * * We need at least 6 vertical lines to render the screen. This would * leave 0 lines for the body. Therefore, we require 7 lines so there's * at least one body line. Similarly, we need 2 horizontal cells for the * frame, so we require 3. * If the window is too small, we print an error message instead. */ if (o->in_width < 1 || o->in_height < 1) { output_printf(o, "\e[2J" /* erase-in-display: whole screen */ "\e[H"); /* cursor-position: home */ output_printf(o, "error: screen too small, need at least 3x7 cells"); output_flush(o); return; } /* hide cursor */ output_printf(o, "\e[?25l"); /* frame-content is contant; only resizes can change it */ if (o->resized || o->in_menu != menu) { output_printf(o, "\e[2J" /* erase-in-display: whole screen */ "\e[H"); /* cursor-position: home */ output_draw_frame(o); o->resized = false; o->in_menu = menu; } /* move cursor to child's position */ output_move_to(o, 1, 3); if (menu) output_draw_menu(o); else output_draw_screen(o, screen); /* show cursor */ if (!(screen->flags & TERM_FLAG_HIDE_CURSOR)) output_printf(o, "\e[?25h"); /* * Hack: sd-term was not written to support TTY as output-objects, thus * expects callers to use term_screen_feed_keyboard(). However, we * forward TTY input directly. Hence, we're not notified about keypad * changes. Update the related modes djring redraw to keep them at least * in sync. */ if (screen->flags & TERM_FLAG_CURSOR_KEYS) output_printf(o, "\e[?1h"); else output_printf(o, "\e[?1l"); if (screen->flags & TERM_FLAG_KEYPAD_MODE) output_printf(o, "\e="); else output_printf(o, "\e>"); output_flush(o); } /* * Terminal Handling */ static void terminal_dirty(Terminal *t) { usec_t usec; int r; assert(t); if (t->is_scheduled) { t->is_dirty = true; return; } /* 16ms timer */ r = sd_event_now(t->event, CLOCK_MONOTONIC, &usec); assert(r >= 0); usec += 16 * USEC_PER_MSEC; r = sd_event_source_set_time(t->frame_timer, usec); if (r >= 0) { r = sd_event_source_set_enabled(t->frame_timer, SD_EVENT_ONESHOT); if (r >= 0) t->is_scheduled = true; } t->is_dirty = false; output_draw(t->output, t->is_menu, t->screen); } static int terminal_frame_timer_fn(sd_event_source *source, uint64_t usec, void *userdata) { Terminal *t = userdata; t->is_scheduled = false; if (t->is_dirty) terminal_dirty(t); return 0; } static int terminal_winch_fn(sd_event_source *source, const struct signalfd_siginfo *ssi, void *userdata) { Terminal *t = userdata; int r; output_winch(t->output); if (t->pty) { r = pty_resize(t->pty, t->output->in_width, t->output->in_height); if (r < 0) log_error("error: pty_resize() (%d): %s", r, strerror(-r)); } r = term_screen_resize(t->screen, t->output->in_width, t->output->in_height); if (r < 0) log_error("error: term_screen_resize() (%d): %s", r, strerror(-r)); terminal_dirty(t); return 0; } static int terminal_push_tmp(Terminal *t, uint32_t ucs4) { char buf[4]; size_t len; int r; assert(t); len = term_utf8_encode(buf, ucs4); if (len < 1) return 0; r = ring_push(&t->out_ring, buf, len); if (r < 0) log_oom(); return r; } static int terminal_write_tmp(Terminal *t) { struct iovec vec[2]; size_t num, i; int r; assert(t); num = ring_peek(&t->out_ring, vec); if (num < 1) return 0; if (t->pty) { for (i = 0; i < num; ++i) { r = pty_write(t->pty, vec[i].iov_base, vec[i].iov_len); if (r < 0) { log_error("error: cannot write to PTY (%d): %s", r, strerror(-r)); return r; } } } ring_flush(&t->out_ring); return 0; } static void terminal_discard_tmp(Terminal *t) { assert(t); ring_flush(&t->out_ring); } static int terminal_menu(Terminal *t, const term_seq *seq) { switch (seq->type) { case TERM_SEQ_IGNORE: break; case TERM_SEQ_GRAPHIC: switch (seq->terminator) { case 'q': sd_event_exit(t->event, 0); return 0; } break; case TERM_SEQ_CONTROL: switch (seq->terminator) { case 0x03: terminal_push_tmp(t, 0x03); terminal_write_tmp(t); break; } break; } t->is_menu = false; terminal_dirty(t); return 0; } static int terminal_io_fn(sd_event_source *source, int fd, uint32_t revents, void *userdata) { Terminal *t = userdata; char buf[4096]; ssize_t len, i; int r, type; len = read(fd, buf, sizeof(buf)); if (len < 0) { if (errno == EAGAIN || errno == EINTR) return 0; log_error("error: cannot read from TTY (%d): %m", -errno); return -errno; } for (i = 0; i < len; ++i) { const term_seq *seq; const uint32_t *str; size_t n_str, j; str = term_utf8_decode(&t->utf8, &n_str, buf[i]); for (j = 0; j < n_str; ++j) { type = term_parser_feed(t->parser, &seq, str[j]); if (type < 0) { log_error("error: term_parser_feed() (%d): %s", type, strerror(-type)); return type; } if (!t->is_menu) { r = terminal_push_tmp(t, str[j]); if (r < 0) return r; } if (type == TERM_SEQ_NONE) { /* We only intercept one-char sequences, so in * case term_parser_feed() couldn't parse a * sequence, it is waiting for more data. We * know it can never be a one-char sequence * then, so we can safely forward the data. * This avoids withholding ESC or other values * that may be one-shot depending on the * application. */ r = terminal_write_tmp(t); if (r < 0) return r; } else if (t->is_menu) { r = terminal_menu(t, seq); if (r < 0) return r; } else if (seq->type == TERM_SEQ_CONTROL && seq->terminator == 0x03) { /* ^C opens the menu */ terminal_discard_tmp(t); t->is_menu = true; terminal_dirty(t); } else { r = terminal_write_tmp(t); if (r < 0) return r; } } } return 0; } static int terminal_pty_fn(Pty *pty, void *userdata, unsigned int event, const void *ptr, size_t size) { Terminal *t = userdata; int r; switch (event) { case PTY_CHILD: sd_event_exit(t->event, 0); break; case PTY_DATA: r = term_screen_feed_text(t->screen, ptr, size); if (r < 0) { log_error("error: term_screen_feed_text() (%d): %s", r, strerror(-r)); return r; } terminal_dirty(t); break; } return 0; } static int terminal_write_fn(term_screen *screen, void *userdata, const void *buf, size_t size) { Terminal *t = userdata; int r; if (!t->pty) return 0; r = ring_push(&t->out_ring, buf, size); if (r < 0) log_oom(); return r; } static int terminal_cmd_fn(term_screen *screen, void *userdata, unsigned int cmd, const term_seq *seq) { return 0; } static Terminal *terminal_free(Terminal *t) { if (!t) return NULL; ring_clear(&t->out_ring); term_screen_unref(t->screen); term_parser_free(t->parser); output_free(t->output); sd_event_source_unref(t->frame_timer); sd_event_unref(t->event); tcsetattr(t->in_fd, TCSANOW, &t->saved_in_attr); tcsetattr(t->out_fd, TCSANOW, &t->saved_out_attr); free(t); return NULL; } static int terminal_new(Terminal **out, int in_fd, int out_fd) { struct termios in_attr, out_attr; Terminal *t; int r; assert_return(out, -EINVAL); r = tcgetattr(in_fd, &in_attr); if (r < 0) { log_error("error: tcgetattr() (%d): %m", -errno); return -errno; } r = tcgetattr(out_fd, &out_attr); if (r < 0) { log_error("error: tcgetattr() (%d): %m", -errno); return -errno; } t = new0(Terminal, 1); if (!t) return log_oom(); t->in_fd = in_fd; t->out_fd = out_fd; memcpy(&t->saved_in_attr, &in_attr, sizeof(in_attr)); memcpy(&t->saved_out_attr, &out_attr, sizeof(out_attr)); cfmakeraw(&in_attr); cfmakeraw(&out_attr); r = tcsetattr(t->in_fd, TCSANOW, &in_attr); if (r < 0) { log_error("error: tcsetattr() (%d): %s", r, strerror(-r)); goto error; } r = tcsetattr(t->out_fd, TCSANOW, &out_attr); if (r < 0) { log_error("error: tcsetattr() (%d): %s", r, strerror(-r)); goto error; } r = sd_event_default(&t->event); if (r < 0) { log_error("error: sd_event_default() (%d): %s", r, strerror(-r)); goto error; } r = sigprocmask_many(SIG_BLOCK, SIGINT, SIGQUIT, SIGTERM, SIGWINCH, SIGCHLD, -1); if (r < 0) { log_error("error: sigprocmask_many() (%d): %s", r, strerror(-r)); goto error; } r = sd_event_add_signal(t->event, NULL, SIGINT, NULL, NULL); if (r < 0) { log_error("error: sd_event_add_signal() (%d): %s", r, strerror(-r)); goto error; } r = sd_event_add_signal(t->event, NULL, SIGQUIT, NULL, NULL); if (r < 0) { log_error("error: sd_event_add_signal() (%d): %s", r, strerror(-r)); goto error; } r = sd_event_add_signal(t->event, NULL, SIGTERM, NULL, NULL); if (r < 0) { log_error("error: sd_event_add_signal() (%d): %s", r, strerror(-r)); goto error; } r = sd_event_add_signal(t->event, NULL, SIGWINCH, terminal_winch_fn, t); if (r < 0) { log_error("error: sd_event_add_signal() (%d): %s", r, strerror(-r)); goto error; } /* force initial redraw on event-loop enter */ t->is_dirty = true; r = sd_event_add_time(t->event, &t->frame_timer, CLOCK_MONOTONIC, 0, 0, terminal_frame_timer_fn, t); if (r < 0) { log_error("error: sd_event_add_time() (%d): %s", r, strerror(-r)); goto error; } r = output_new(&t->output, out_fd); if (r < 0) goto error; r = term_parser_new(&t->parser, true); if (r < 0) goto error; r = term_screen_new(&t->screen, terminal_write_fn, t, terminal_cmd_fn, t); if (r < 0) goto error; r = term_screen_set_answerback(t->screen, "systemd-subterm"); if (r < 0) goto error; r = term_screen_resize(t->screen, t->output->in_width, t->output->in_height); if (r < 0) { log_error("error: term_screen_resize() (%d): %s", r, strerror(-r)); goto error; } r = sd_event_add_io(t->event, NULL, in_fd, EPOLLIN, terminal_io_fn, t); if (r < 0) goto error; *out = t; return 0; error: terminal_free(t); return r; } static int terminal_run(Terminal *t) { pid_t pid; assert_return(t, -EINVAL); pid = pty_fork(&t->pty, t->event, terminal_pty_fn, t, t->output->in_width, t->output->in_height); if (pid < 0) { log_error("error: cannot fork PTY (%d): %s", pid, strerror(-pid)); return pid; } else if (pid == 0) { /* child */ char **argv = (char*[]){ (char*)getenv("SHELL") ? : (char*)_PATH_BSHELL, NULL }; setenv("TERM", "xterm-256color", 1); setenv("COLORTERM", "systemd-subterm", 1); execve(argv[0], argv, environ); log_error("error: cannot exec %s (%d): %m", argv[0], -errno); _exit(1); } /* parent */ return sd_event_loop(t->event); } /* * Context Handling */ int main(int argc, char *argv[]) { Terminal *t = NULL; int r; r = terminal_new(&t, 0, 1); if (r < 0) goto out; r = terminal_run(t); if (r < 0) goto out; out: if (r < 0) log_error("error: terminal failed (%d): %s", r, strerror(-r)); terminal_free(t); return -r; }