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/*
* Copyright (C) 2020, Red Hat Inc.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version 2
* of the License, or (at your option) any later version.
*
* This program 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 General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
* 02110-1301, USA.
*
* Author: Carlos Garnacho <carlosg@gnome.org>
*/
#include "tracker-term-utils.h"
#include <gio/gio.h>
#include <glib-unix.h>
#include <sys/ioctl.h>
#include <unistd.h>
#include <fcntl.h>
#include <stdio.h>
static guint n_columns = 0;
static guint n_rows = 0;
static GSubprocess *pager = NULL;
static gint stdout_fd = 0;
static guint signal_handler_id = 0;
gchar *
tracker_term_ellipsize (const gchar *str,
gint max_len,
TrackerEllipsizeMode mode)
{
gsize size = strlen (str);
glong len = g_utf8_strlen (str, size);
const gchar *begin, *end, *pos;
gchar *substr, *retval;
gint i;
if (len < max_len)
return g_strdup (str);
/* Account for the ellipsizing char */
max_len--;
if (max_len <= 0)
return g_strdup ("…");
begin = str;
end = &str[size];
if (mode == TRACKER_ELLIPSIZE_END) {
pos = begin;
for (i = 0; i < max_len; i++)
pos = g_utf8_find_next_char (pos, end);
substr = g_strndup (begin, pos - begin);
retval = g_strdup_printf ("%s…", substr);
g_free (substr);
} else {
pos = end;
for (i = 0; i < max_len; i++)
pos = g_utf8_find_prev_char (begin, pos);
substr = g_strndup (pos, end - pos);
retval = g_strdup_printf ("…%s", substr);
g_free (substr);
}
return retval;
}
static gboolean
fd_term_dimensions (gint fd,
gint *cols,
gint *rows)
{
struct winsize ws = {};
if (ioctl(fd, TIOCGWINSZ, &ws) < 0)
return FALSE;
if (ws.ws_col <= 0 || ws.ws_row <= 0)
return FALSE;
*cols = ws.ws_col;
*rows = ws.ws_row;
return TRUE;
}
void
tracker_term_dimensions (guint *columns,
guint *rows)
{
if (n_columns == 0 || n_rows == 0)
fd_term_dimensions (STDOUT_FILENO, &n_columns, &n_rows);
if (n_columns <= 0)
n_columns = 80;
if (n_rows <= 0)
n_rows = 24;
if (columns)
*columns = n_columns;
if (rows)
*rows = n_rows;
}
gboolean
tracker_term_is_tty (void)
{
return isatty (STDOUT_FILENO) > 0;
}
static gboolean
ignore_signal_cb (gpointer user_data)
{
return G_SOURCE_CONTINUE;
}
static gchar *
best_pager (void)
{
guint i;
gchar *command;
const gchar *pagers[] = {
"pager",
"less",
"most",
"more",
};
for (i = 0; i < G_N_ELEMENTS (pagers); i++) {
command = g_find_program_in_path (pagers[i]);
if (command)
return command;
}
return NULL;
}
gboolean
tracker_term_pipe_to_pager (void)
{
GSubprocessLauncher *launcher;
gchar *pager_command;
gint fds[2];
if (!tracker_term_is_tty ())
return FALSE;
if (g_unix_open_pipe (fds, FD_CLOEXEC, NULL) < 0)
return FALSE;
pager_command = best_pager ();
if (!pager_command)
return FALSE;
/* Ensure this is cached before we redirect to the pager */
tracker_term_dimensions (NULL, NULL);
launcher = g_subprocess_launcher_new (G_SUBPROCESS_FLAGS_NONE);
g_subprocess_launcher_take_stdin_fd (launcher, fds[0]);
g_subprocess_launcher_setenv (launcher, "LESS", "FRSXMK", TRUE);
pager = g_subprocess_launcher_spawn (launcher, NULL, pager_command, NULL);
g_free (pager_command);
stdout_fd = dup (STDOUT_FILENO);
close (fds[0]);
if (dup2(fds[1], STDOUT_FILENO) < 0)
return FALSE;
close (fds[1]);
signal_handler_id = g_unix_signal_add (SIGINT, ignore_signal_cb, NULL);
return TRUE;
}
gboolean
tracker_term_pager_close (void)
{
if (!pager)
return FALSE;
fflush (stdout);
/* Restore stdout */
dup2 (stdout_fd, STDOUT_FILENO);
close (stdout_fd);
g_subprocess_send_signal (pager, SIGCONT);
g_subprocess_wait (pager, NULL, NULL);
g_source_remove (signal_handler_id);
return TRUE;
}
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