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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-05-06 01:16:24 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-05-06 01:16:24 +0000 |
commit | 9221dca64f0c8b5de72727491e41cf63e902eaab (patch) | |
tree | d8cbbf520eb4b5c656a54b2e36947008dcb751ad /lib/linelength.c | |
parent | Initial commit. (diff) | |
download | man-db-9221dca64f0c8b5de72727491e41cf63e902eaab.tar.xz man-db-9221dca64f0c8b5de72727491e41cf63e902eaab.zip |
Adding upstream version 2.8.5.upstream/2.8.5upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'lib/linelength.c')
-rw-r--r-- | lib/linelength.c | 108 |
1 files changed, 108 insertions, 0 deletions
diff --git a/lib/linelength.c b/lib/linelength.c new file mode 100644 index 0000000..69a702f --- /dev/null +++ b/lib/linelength.c @@ -0,0 +1,108 @@ +/* + * linelength.c: find the terminal line length + * Preferences: 1. MANWIDTH, 2. COLUMNS, 3. ioctl, 4. 80 + * + * Originally adapted from Andries Brouwer's man implementation, also + * released under the GPL: authors believed to include Martin Schulze and + * Jon Tombs, dated 1995/09/02. + * + * Changes for man-db copyright (C) 2001, 2003, 2007 Colin Watson. + * + * This file is part of man-db. + * + * man-db 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. + * + * man-db 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 man-db; if not, write to the Free Software Foundation, + * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. + */ + +#ifdef HAVE_CONFIG_H +# include "config.h" +#endif /* HAVE_CONFIG_H */ + +#include <stdlib.h> +#include <stdio.h> +#include <unistd.h> +#include <termios.h> +#include <sys/ioctl.h> +#include <sys/types.h> +#include <sys/stat.h> +#include <fcntl.h> + +#ifndef _PATH_TTY +# define _PATH_TTY "/dev/tty" +#endif /* _PATH_TTY */ + +static int line_length = -1; + +int get_line_length (void) +{ + const char *columns; + int width; +#ifdef TIOCGWINSZ + int dev_tty, tty_fd = -1; +#endif + + if (line_length != -1) + return line_length; + + line_length = 80; + + columns = getenv ("MANWIDTH"); + if (columns != NULL) { + width = atoi (columns); + if (width > 0) + return line_length = width; + } + + columns = getenv ("COLUMNS"); + if (columns != NULL) { + width = atoi (columns); + if (width > 0) + return line_length = width; + } + +#ifdef TIOCGWINSZ + /* Original TIOCGWINSZ approach was from Jon Tombs. + * We don't require both stdin and stdout to be a tty, and line + * length is primarily a property of output. However, if it happens + * that stdin is connected to a terminal but stdout isn't, then that + * may well be because the user is trying something like + * 'MAN_KEEP_STDERR=1 man foo >/dev/null' to see just the error + * messages, so use the window size from stdin as a fallback. + * In some cases we may have neither (e.g. if man is running inside + * lesspipe); /dev/tty should be a reliable way to get to the + * current tty if it exists. + */ + dev_tty = open (_PATH_TTY, O_RDONLY); + if (dev_tty >= 0) + tty_fd = dev_tty; + else if (isatty (STDOUT_FILENO)) + tty_fd = STDOUT_FILENO; + else if (isatty (STDIN_FILENO)) + tty_fd = STDIN_FILENO; + if (tty_fd >= 0) { + int ret; + struct winsize wsz; + + ret = ioctl (tty_fd, TIOCGWINSZ, &wsz); + if (dev_tty >= 0) + close (dev_tty); + if (ret) + perror ("TIOCGWINSZ failed"); + else if (wsz.ws_col) + return line_length = wsz.ws_col; + } +#endif + + return line_length = 80; +} |