subterm.c revision 553acb7b6b8d4f16a4747b1f978e8b7888fbfb2c
/*-*- 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)
return log_error_errno(errno, "error: cannot read window-size: %m");
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) {
int r;
if (o->n_obuf < 1)
return 0;
r = loop_write(o->fd, o->obuf, o->n_obuf, false);
if (r < 0)
return log_error_errno(r, "error: cannot write to TTY: %m");
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)
return log_error_errno(len, "error: cannot write to TTY (%zd): %m", 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;
/* re-enable cursor */
output_printf(o, "\e[?25h");
/* 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;
/* always hide cursor */
r = output_printf(o, "\e[?25l");
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 int output_draw_cell_fn(term_screen *screen,
void *userdata,
unsigned int x,
unsigned int y,
const term_attr *attr,
const uint32_t *ch,
size_t n_ch,
unsigned int ch_width) {
Output *o = userdata;
size_t k, ulen;
char utf8[4];
if (x >= o->in_width || y >= o->in_height)
return 0;
if (x == 0 && y != 0)
output_printf(o, "\e[m\r\n" BORDER_VERT);
switch (attr->fg.ccode) {
case TERM_CCODE_DEFAULT:
output_printf(o, "\e[39m");
break;
case TERM_CCODE_256:
output_printf(o, "\e[38;5;%um", attr->fg.c256);
break;
case TERM_CCODE_RGB:
output_printf(o, "\e[38;2;%u;%u;%um", attr->fg.red, attr->fg.green, attr->fg.blue);
break;
case TERM_CCODE_BLACK ... TERM_CCODE_WHITE:
output_printf(o, "\e[%um", attr->fg.ccode - TERM_CCODE_BLACK + 30);
break;
case TERM_CCODE_LIGHT_BLACK ... TERM_CCODE_LIGHT_WHITE:
output_printf(o, "\e[%um", attr->fg.ccode - TERM_CCODE_LIGHT_BLACK + 90);
break;
}
switch (attr->bg.ccode) {
case TERM_CCODE_DEFAULT:
output_printf(o, "\e[49m");
break;
case TERM_CCODE_256:
output_printf(o, "\e[48;5;%um", attr->bg.c256);
break;
case TERM_CCODE_RGB:
output_printf(o, "\e[48;2;%u;%u;%um", attr->bg.red, attr->bg.green, attr->bg.blue);
break;
case TERM_CCODE_BLACK ... TERM_CCODE_WHITE:
output_printf(o, "\e[%um", attr->bg.ccode - TERM_CCODE_BLACK + 40);
break;
case TERM_CCODE_LIGHT_BLACK ... TERM_CCODE_LIGHT_WHITE:
output_printf(o, "\e[%um", attr->bg.ccode - TERM_CCODE_LIGHT_BLACK + 100);
break;
}
output_printf(o, "\e[%u;%u;%u;%u;%u;%um",
attr->bold ? 1 : 22,
attr->italic ? 3 : 23,
attr->underline ? 4 : 24,
attr->inverse ? 7 : 27,
attr->blink ? 5 : 25,
attr->hidden ? 8 : 28);
if (n_ch < 1) {
output_printf(o, " ");
} else {
for (k = 0; k < n_ch; ++k) {
ulen = term_utf8_encode(utf8, ch[k]);
output_write(o, utf8, ulen);
}
}
return 0;
}
static void output_draw_screen(Output *o, term_screen *s) {
assert(o);
assert(s);
term_screen_draw(s, output_draw_cell_fn, o, NULL);
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);
/*
* 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_errno(r, "error: pty_resize() (%d): %m", r);
}
r = term_screen_resize(t->screen, t->output->in_width, t->output->in_height);
if (r < 0)
log_error_errno(r, "error: term_screen_resize() (%d): %m", 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)
return log_error_errno(r, "error: cannot write to PTY (%d): %m", 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_errno(errno, "error: cannot read from TTY (%d): %m", -errno);
return -errno;
}
for (i = 0; i < len; ++i) {
const term_seq *seq;
uint32_t *str;
size_t n_str, j;
n_str = term_utf8_decode(&t->utf8, &str, buf[i]);
for (j = 0; j < n_str; ++j) {
type = term_parser_feed(t->parser, &seq, str[j]);
if (type < 0)
return log_error_errno(type, "error: term_parser_feed() (%d): %m", 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)
return log_error_errno(r, "error: term_screen_feed_text() (%d): %m", 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)
return log_error_errno(errno, "error: tcgetattr() (%d): %m", -errno);
r = tcgetattr(out_fd, &out_attr);
if (r < 0)
return log_error_errno(errno, "error: tcgetattr() (%d): %m", -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_errno(r, "error: tcsetattr() (%d): %m", r);
goto error;
}
r = tcsetattr(t->out_fd, TCSANOW, &out_attr);
if (r < 0) {
log_error_errno(r, "error: tcsetattr() (%d): %m", r);
goto error;
}
r = sd_event_default(&t->event);
if (r < 0) {
log_error_errno(r, "error: sd_event_default() (%d): %m", r);
goto error;
}
r = sigprocmask_many(SIG_BLOCK, SIGINT, SIGQUIT, SIGTERM, SIGWINCH, SIGCHLD, -1);
if (r < 0) {
log_error_errno(r, "error: sigprocmask_many() (%d): %m", r);
goto error;
}
r = sd_event_add_signal(t->event, NULL, SIGINT, NULL, NULL);
if (r < 0) {
log_error_errno(r, "error: sd_event_add_signal() (%d): %m", r);
goto error;
}
r = sd_event_add_signal(t->event, NULL, SIGQUIT, NULL, NULL);
if (r < 0) {
log_error_errno(r, "error: sd_event_add_signal() (%d): %m", r);
goto error;
}
r = sd_event_add_signal(t->event, NULL, SIGTERM, NULL, NULL);
if (r < 0) {
log_error_errno(r, "error: sd_event_add_signal() (%d): %m", r);
goto error;
}
r = sd_event_add_signal(t->event, NULL, SIGWINCH, terminal_winch_fn, t);
if (r < 0) {
log_error_errno(r, "error: sd_event_add_signal() (%d): %m", 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_errno(r, "error: sd_event_add_time() (%d): %m", 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_errno(r, "error: term_screen_resize() (%d): %m", 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)
return log_error_errno(pid, "error: cannot fork PTY (%d): %m", 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_errno(errno, "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_errno(r, "error: terminal failed (%d): %m", r);
terminal_free(t);
return -r;
}