Rework option handling to save space.
[oweals/busybox.git] / util-linux / more.c
1 /* vi: set sw=4 ts=4: */
2 /*
3  * Mini more implementation for busybox
4  *
5  *
6  * Copyright (C) 1995, 1996 by Bruce Perens <bruce@pixar.com>.
7  *
8  * Latest version blended together by Erik Andersen <andersen@lineo.com>,
9  * based on the original more implementation by Bruce, and code from the 
10  * Debian boot-floppies team.
11  *
12  * Termios corrects by Vladimir Oleynik <vodz@usa.net>
13  *
14  * This program is free software; you can redistribute it and/or modify
15  * it under the terms of the GNU General Public License as published by
16  * the Free Software Foundation; either version 2 of the License, or
17  * (at your option) any later version.
18  *
19  * This program is distributed in the hope that it will be useful,
20  * but WITHOUT ANY WARRANTY; without even the implied warranty of
21  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
22  * General Public License for more details.
23  *
24  * You should have received a copy of the GNU General Public License
25  * along with this program; if not, write to the Free Software
26  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
27  *
28  */
29
30 #include <stdio.h>
31 #include <fcntl.h>
32 #include <signal.h>
33 #include <stdlib.h>
34 #include <unistd.h>
35 #include <sys/ioctl.h>
36 #include "busybox.h"
37
38 static FILE *cin;
39
40 #ifdef BB_FEATURE_USE_TERMIOS
41 #include <termios.h>
42 #define setTermSettings(fd,argp) tcsetattr(fd,TCSANOW,argp)
43 #define getTermSettings(fd,argp) tcgetattr(fd, argp);
44
45 static struct termios initial_settings, new_settings;
46
47 static void set_tty_to_initial_mode(void)
48 {
49         setTermSettings(fileno(cin), &initial_settings);
50 }
51
52 static void gotsig(int sig)
53 {
54         putchar('\n');
55         exit(EXIT_FAILURE);
56 }
57 #endif /* BB_FEATURE_USE_TERMIOS */
58
59
60 static int terminal_width = 79; /* not 80 in case terminal has linefold bug */
61 static int terminal_height = 24;
62
63
64 extern int more_main(int argc, char **argv)
65 {
66         int c, lines, input = 0;
67         int please_display_more_prompt = -1;
68         struct stat st;
69         FILE *file;
70         int len, page_height;
71
72 #if defined BB_FEATURE_AUTOWIDTH && defined BB_FEATURE_USE_TERMIOS
73         struct winsize win = { 0, 0, 0, 0 };
74 #endif
75
76         argc--;
77         argv++;
78
79
80         /* not use inputing from terminal if usage: more > outfile */
81         if(isatty(fileno(stdout))) {
82                 cin = fopen(CURRENT_TTY, "r");
83                 if (!cin)
84                         cin = xfopen(CONSOLE_DEV, "r");
85                 please_display_more_prompt = 0;
86 #ifdef BB_FEATURE_USE_TERMIOS
87                 getTermSettings(fileno(cin), &initial_settings);
88                 new_settings = initial_settings;
89                 new_settings.c_lflag &= ~ICANON;
90                 new_settings.c_lflag &= ~ECHO;
91 #ifndef linux
92                 /* Hmm, in linux c_cc[] not parsed if set ~ICANON */
93                 new_settings.c_cc[VMIN] = 1;
94                 new_settings.c_cc[VTIME] = 0;
95 #endif
96                 setTermSettings(fileno(cin), &new_settings);
97                 atexit(set_tty_to_initial_mode);
98                 (void) signal(SIGINT, gotsig);
99                 (void) signal(SIGQUIT, gotsig);
100                 (void) signal(SIGTERM, gotsig);
101 #endif
102         }
103
104         do {
105                 if (argc == 0) {
106                         file = stdin;
107                 } else
108                         file = wfopen(*argv, "r");
109                 if(file==0)
110                         goto loop;
111                         
112                 fstat(fileno(file), &st);
113
114                 if(please_display_more_prompt>0)
115                         please_display_more_prompt = 0;
116
117 #if defined BB_FEATURE_AUTOWIDTH && defined BB_FEATURE_USE_TERMIOS
118                 ioctl(fileno(stdout), TIOCGWINSZ, &win);
119                 if (win.ws_row > 4)
120                         terminal_height = win.ws_row - 2;
121                 if (win.ws_col > 0)
122                         terminal_width = win.ws_col - 1;
123 #endif
124                 len=0;
125                 lines = 0;
126                 page_height = terminal_height;
127                 while ((c = getc(file)) != EOF) {
128
129                         if (please_display_more_prompt>0) {
130                                 len = printf("--More-- ");
131                                 if (file != stdin) {
132 #if _FILE_OFFSET_BITS == 64
133                                         len += printf("(%d%% of %lld bytes)",
134                                                    (int) (100 * ((double) ftell(file) /
135                                                    (double) st.st_size)), (long long)st.st_size);
136 #else
137                                         len += printf("(%d%% of %ld bytes)",
138                                                    (int) (100 * ((double) ftell(file) /
139                                                    (double) st.st_size)), (long)st.st_size);
140 #endif
141                                 }
142
143                                 fflush(stdout);
144
145                                 /*
146                                  * We've just displayed the "--More--" prompt, so now we need
147                                  * to get input from the user.
148                                  */
149                                 input = getc(cin);
150 #ifndef BB_FEATURE_USE_TERMIOS
151                                 printf("\033[A"); /* up cursor */
152 #endif
153                                 /* Erase the "More" message */
154                                 putc('\r', stdout);
155                                 while (--len >= 0)
156                                         putc(' ', stdout);
157                                 putc('\r', stdout);
158                                 fflush(stdout);
159                                 len=0;
160                                 lines = 0;
161                                 page_height = terminal_height;
162                                 please_display_more_prompt = 0;
163
164                                 if (input == 'q')
165                                         goto end;
166                         }
167
168                         /* 
169                          * There are two input streams to worry about here:
170                          *
171                          * c     : the character we are reading from the file being "mored"
172                          * input : a character received from the keyboard
173                          *
174                          * If we hit a newline in the _file_ stream, we want to test and
175                          * see if any characters have been hit in the _input_ stream. This
176                          * allows the user to quit while in the middle of a file.
177                          */
178                         if (c == '\n') {
179                                 /* increment by just one line if we are at
180                                  * the end of this line */
181                                 if (input == '\n')
182                                         if(please_display_more_prompt==0)
183                                         please_display_more_prompt = 1;
184                                 /* Adjust the terminal height for any overlap, so that
185                                  * no lines get lost off the top. */
186                                 if (len >= terminal_width) {
187                                         int quot, rem;
188                                         quot = len / terminal_width;
189                                         rem  = len - (quot * terminal_width);
190                                         if (quot) {
191                                                 if (rem)
192                                                         page_height-=quot;
193                                                 else
194                                                         page_height-=(quot-1);
195                                         }
196                                 }
197                                 if (++lines >= page_height) {
198                                         if(please_display_more_prompt==0)
199                                         please_display_more_prompt = 1;
200                                 }
201                                 len=0;
202                         }
203                         /*
204                          * If we just read a newline from the file being 'mored' and any
205                          * key other than a return is hit, scroll by one page
206                          */
207                         putc(c, stdout);
208                         len++;
209                 }
210                 fclose(file);
211                 fflush(stdout);
212 loop:
213                 argv++;
214         } while (--argc > 0);
215   end:
216         return 0;
217 }