a few minor cleanups.
[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  * This program is free software; you can redistribute it and/or modify
13  * it under the terms of the GNU General Public License as published by
14  * the Free Software Foundation; either version 2 of the License, or
15  * (at your option) any later version.
16  *
17  * This program is distributed in the hope that it will be useful,
18  * but WITHOUT ANY WARRANTY; without even the implied warranty of
19  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
20  * General Public License for more details.
21  *
22  * You should have received a copy of the GNU General Public License
23  * along with this program; if not, write to the Free Software
24  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
25  *
26  */
27
28 #include "internal.h"
29 #include <stdio.h>
30 #include <fcntl.h>
31 #include <signal.h>
32 #include <sys/ioctl.h>
33 #define BB_DECLARE_EXTERN
34 #define bb_need_help
35 #include "messages.c"
36
37 static const char more_usage[] = "more [FILE ...]\n"
38 #ifndef BB_FEATURE_TRIVIAL_HELP
39         "\nMore is a filter for viewing FILE one screenful at a time.\n"
40 #endif
41         ;
42
43 /* ED: sparc termios is broken: revert back to old termio handling. */
44 #ifdef BB_FEATURE_USE_TERMIOS
45 #       if #cpu(sparc)
46 #               include <termio.h>
47 #               define termios termio
48 #               define setTermSettings(fd,argp) ioctl(fd,TCSETAF,argp)
49 #               define getTermSettings(fd,argp) ioctl(fd,TCGETA,argp)
50 #       else
51 #               include <termios.h>
52 #               define setTermSettings(fd,argp) tcsetattr(fd,TCSANOW,argp)
53 #               define getTermSettings(fd,argp) tcgetattr(fd, argp);
54 #       endif
55
56 FILE *cin;
57
58 struct termios initial_settings, new_settings;
59
60 void gotsig(int sig)
61 {
62         setTermSettings(fileno(cin), &initial_settings);
63         fprintf(stdout, "\n");
64         exit(TRUE);
65 }
66 #endif /* BB_FEATURE_USE_TERMIOS */
67
68
69 static int terminal_width = 79; /* not 80 in case terminal has linefold bug */
70 static int terminal_height = 24;
71
72
73 extern int more_main(int argc, char **argv)
74 {
75         int c, lines = 0, input = 0;
76         int please_display_more_prompt = 0;
77         struct stat st;
78         FILE *file;
79
80 #if defined BB_FEATURE_AUTOWIDTH && defined BB_FEATURE_USE_TERMIOS
81         struct winsize win = { 0, 0 };
82 #endif
83
84         argc--;
85         argv++;
86
87         if (argc > 0
88                 && (strcmp(*argv, dash_dash_help) == 0 || strcmp(*argv, "-h") == 0)) {
89                 usage(more_usage);
90         }
91         do {
92                 if (argc == 0) {
93                         file = stdin;
94                 } else
95                         file = fopen(*argv, "r");
96
97                 if (file == NULL) {
98                         perror(*argv);
99                         exit(FALSE);
100                 }
101                 fstat(fileno(file), &st);
102
103 #ifdef BB_FEATURE_USE_TERMIOS
104                 cin = fopen("/dev/tty", "r");
105                 if (!cin)
106                         cin = fopen("/dev/console", "r");
107                 getTermSettings(fileno(cin), &initial_settings);
108                 new_settings = initial_settings;
109                 new_settings.c_cc[VMIN] = 1;
110                 new_settings.c_cc[VTIME] = 0;
111                 new_settings.c_lflag &= ~ICANON;
112                 new_settings.c_lflag &= ~ECHO;
113                 setTermSettings(fileno(cin), &new_settings);
114
115 #       ifdef BB_FEATURE_AUTOWIDTH
116                 ioctl(fileno(stdout), TIOCGWINSZ, &win);
117                 if (win.ws_row > 4)
118                         terminal_height = win.ws_row - 2;
119                 if (win.ws_col > 0)
120                         terminal_width = win.ws_col - 1;
121 #       endif
122
123                 (void) signal(SIGINT, gotsig);
124                 (void) signal(SIGQUIT, gotsig);
125                 (void) signal(SIGTERM, gotsig);
126
127 #endif
128                 while ((c = getc(file)) != EOF) {
129                         if (please_display_more_prompt) {
130                                 int len = 0;
131
132                                 please_display_more_prompt = 0;
133                                 lines = 0;
134                                 len = fprintf(stdout, "--More-- ");
135                                 if (file != stdin) {
136                                         len += fprintf(stdout, "(%d%% of %ld bytes)",
137                                                                    (int) (100 *
138                                                                                   ((double) ftell(file) /
139                                                                                    (double) st.st_size)),
140                                                                    st.st_size);
141                                 }
142                                 len += fprintf(stdout, "%s",
143 #ifdef BB_FEATURE_USE_TERMIOS
144                                                            ""
145 #else
146                                                            "\n"
147 #endif
148                                         );
149
150                                 fflush(stdout);
151
152                                 /*
153                                  * We've just displayed the "--More--" prompt, so now we need
154                                  * to get input from the user.
155                                  */
156 #ifdef BB_FEATURE_USE_TERMIOS
157                                 input = getc(cin);
158 #else
159                                 input = getc(stdin);
160 #endif
161
162 #ifdef BB_FEATURE_USE_TERMIOS
163                                 /* Erase the "More" message */
164                                 while (--len >= 0)
165                                         putc('\b', stdout);
166                                 while (++len <= terminal_width)
167                                         putc(' ', stdout);
168                                 while (--len >= 0)
169                                         putc('\b', stdout);
170                                 fflush(stdout);
171 #endif
172
173                         }
174
175                         /* 
176                          * There are two input streams to worry about here:
177                          *
178                          *     c : the character we are reading from the file being "mored"
179                          * input : a character received from the keyboard
180                          *
181                          * If we hit a newline in the _file_ stream, we want to test and
182                          * see if any characters have been hit in the _input_ stream. This
183                          * allows the user to quit while in the middle of a file.
184                          */
185                         if (c == '\n') {
186                                 switch (input) {
187                                 case 'q':
188                                         goto end;
189                                 case '\n':
190                                         /* increment by just one line if we are at 
191                                          * the end of this line*/
192                                         please_display_more_prompt = 1;
193                                         break;
194                                 }
195                                 if (++lines == terminal_height)
196                                         please_display_more_prompt = 1;
197                         }
198                         /*
199                          * If we just read a newline from the file being 'mored' and any
200                          * key other than a return is hit, scroll by one page
201                          */
202                         putc(c, stdout);
203                 }
204                 fclose(file);
205                 fflush(stdout);
206
207                 argv++;
208         } while (--argc > 0);
209   end:
210 #ifdef BB_FEATURE_USE_TERMIOS
211         gotsig(0);
212 #endif
213         return(TRUE);
214 }