1 /* vi: set sw=4 ts=4: */
3 * Mini more implementation for busybox
5 * Copyright (C) 1995, 1996 by Bruce Perens <bruce@pixar.com>.
6 * Copyright (C) 1999-2004 by Erik Andersen <andersen@codepoet.org>
8 * Latest version blended together by Erik Andersen <andersen@codepoet.org>,
9 * based on the original more implementation by Bruce, and code from the
10 * Debian boot-floppies team.
12 * Termios corrects by Vladimir Oleynik <dzo@simtreas.ru>
14 * Licensed under GPLv2 or later, see file LICENSE in this source tree.
17 //usage:#define more_trivial_usage
19 //usage:#define more_full_usage "\n\n"
20 //usage: "View FILE (or stdin) one screenful at a time"
22 //usage:#define more_example_usage
23 //usage: "$ dmesg | more\n"
27 /* Support for FEATURE_USE_TERMIOS */
31 struct termios initial_settings
;
32 struct termios new_settings
;
34 #define G (*(struct globals*)bb_common_bufsiz1)
35 #define INIT_G() ((void)0)
36 #define initial_settings (G.initial_settings)
37 #define new_settings (G.new_settings )
38 #define cin_fileno (G.cin_fileno )
40 #define setTermSettings(fd, argp) \
42 if (ENABLE_FEATURE_USE_TERMIOS) \
43 tcsetattr(fd, TCSANOW, argp); \
45 #define getTermSettings(fd, argp) tcgetattr(fd, argp)
47 static void gotsig(int sig UNUSED_PARAM
)
49 /* bb_putchar_stderr doesn't use stdio buffering,
50 * therefore it is safe in signal handler */
51 bb_putchar_stderr('\n');
52 setTermSettings(cin_fileno
, &initial_settings
);
56 #define CONVERTED_TAB_SIZE 8
58 int more_main(int argc
, char **argv
) MAIN_EXTERNALLY_VISIBLE
;
59 int more_main(int argc UNUSED_PARAM
, char **argv
)
61 int c
= c
; /* for compiler */
65 int please_display_more_prompt
;
70 unsigned terminal_width
;
71 unsigned terminal_height
;
76 /* Another popular pager, most, detects when stdout
77 * is not a tty and turns into cat. This makes sense. */
78 if (!isatty(STDOUT_FILENO
))
80 cin
= fopen_for_read(CURRENT_TTY
);
84 if (ENABLE_FEATURE_USE_TERMIOS
) {
85 cin_fileno
= fileno(cin
);
86 getTermSettings(cin_fileno
, &initial_settings
);
87 new_settings
= initial_settings
;
88 new_settings
.c_lflag
&= ~(ICANON
| ECHO
);
89 new_settings
.c_cc
[VMIN
] = 1;
90 new_settings
.c_cc
[VTIME
] = 0;
91 setTermSettings(cin_fileno
, &new_settings
);
102 file
= fopen_or_warn(*argv
, "r");
107 fstat(fileno(file
), &st
);
109 please_display_more_prompt
= 0;
110 /* never returns w, h <= 1 */
111 get_terminal_width_height(fileno(cin
), &terminal_width
, &terminal_height
);
112 terminal_height
-= 1;
116 while (spaces
|| (c
= getc(file
)) != EOF
) {
121 if (input
!= 'r' && please_display_more_prompt
) {
122 len
= printf("--More-- ");
123 if (st
.st_size
!= 0) {
124 uoff_t d
= (uoff_t
)st
.st_size
/ 100;
127 len
+= printf("(%u%% of %"OFF_FMT
"u bytes)",
128 (int) ((uoff_t
)ftello(file
) / d
),
134 * We've just displayed the "--More--" prompt, so now we need
135 * to get input from the user.
139 input
= tolower(input
);
140 if (!ENABLE_FEATURE_USE_TERMIOS
)
141 printf("\033[A"); /* cursor up */
142 /* Erase the last message */
143 printf("\r%*s\r", len
, "");
145 /* Due to various multibyte escape
146 * sequences, it's not ok to accept
147 * any input as a command to scroll
148 * the screen. We only allow known
149 * commands, else we show help msg. */
150 if (input
== ' ' || input
== '\n' || input
== 'q' || input
== 'r')
152 len
= printf("(Enter:next line Space:next page Q:quit R:show the rest)");
156 please_display_more_prompt
= 0;
161 /* The user may have resized the terminal.
162 * Re-read the dimensions. */
163 if (ENABLE_FEATURE_USE_TERMIOS
) {
164 get_terminal_width_height(cin_fileno
, &terminal_width
, &terminal_height
);
165 terminal_height
-= 1;
169 /* Crudely convert tabs into spaces, which are
170 * a bajillion times easier to deal with. */
172 spaces
= ((unsigned)~len
) % CONVERTED_TAB_SIZE
;
177 * There are two input streams to worry about here:
179 * c : the character we are reading from the file being "mored"
180 * input: a character received from the keyboard
182 * If we hit a newline in the _file_ stream, we want to test and
183 * see if any characters have been hit in the _input_ stream. This
184 * allows the user to quit while in the middle of a file.
186 wrap
= (++len
> terminal_width
);
187 if (c
== '\n' || wrap
) {
188 /* Then outputting this character
189 * will move us to a new line. */
190 if (++lines
>= terminal_height
|| input
== '\n')
191 please_display_more_prompt
= 1;
194 if (c
!= '\n' && wrap
) {
195 /* Then outputting this will also put a character on
196 * the beginning of that new line. Thus we first want to
197 * display the prompt (if any), so we skip the putchar()
198 * and go back to the top of the loop, without reading
199 * a new character. */
202 /* My small mind cannot fathom backspaces and UTF-8 */
204 die_if_ferror_stdout(); /* if tty was destroyed (closed xterm, etc) */
208 } while (*argv
&& *++argv
);
210 setTermSettings(cin_fileno
, &initial_settings
);