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authorDavid Herrmann <dh.herrmann@gmail.com>2014-07-17 11:10:53 +0200
committerDavid Herrmann <dh.herrmann@gmail.com>2014-07-18 12:53:41 +0200
commit5ab887e98d80ffaf05a97abe4cdc1553a85f0637 (patch)
treedf14266f2f3b73685b749da519731328bd099a25 /src/libsystemd-terminal
parente432f9e8f999fe75d79a2499035c8e84b04a8b1a (diff)
terminal: add systemd-subterm example
The systemd-subterm example is a stacked terminal that shows how to use sd-term. Instead of rendering images and displaying it via X11/etc., it uses its parent terminal to display the page (terminal-emulator inside a terminal-emulator) (like GNU-screen and friends do). This is only for testing and not installed system-wide!
Diffstat (limited to 'src/libsystemd-terminal')
-rw-r--r--src/libsystemd-terminal/subterm.c991
1 files changed, 991 insertions, 0 deletions
diff --git a/src/libsystemd-terminal/subterm.c b/src/libsystemd-terminal/subterm.c
new file mode 100644
index 0000000000..72ce2f6f6e
--- /dev/null
+++ b/src/libsystemd-terminal/subterm.c
@@ -0,0 +1,991 @@
+/*-*- 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;
+}
+
+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);
+}
+
+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;
+}
+
+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);
+}
+
+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;
+}
+
+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, "");
+ 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) {
+ uint64_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;
+}