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15637ed4 RG |
1 | /* unix.c */ |
2 | ||
3 | /* Author: | |
4 | * Steve Kirkendall | |
5 | * 14407 SW Teal Blvd. #C | |
6 | * Beaverton, OR 97005 | |
7 | * kirkenda@cs.pdx.edu | |
8 | */ | |
9 | ||
10 | ||
11 | /* This file contains the unix-specific versions the ttyread() functions. | |
12 | * There are actually three versions of ttyread() defined here, because | |
13 | * BSD, SysV, and V7 all need quite different implementations. | |
14 | */ | |
15 | ||
16 | #include "config.h" | |
17 | #if ANY_UNIX | |
18 | # include "vi.h" | |
19 | ||
20 | # if BSD | |
21 | /* For BSD, we use select() to wait for characters to become available, | |
22 | * and then do a read() to actually get the characters. We also try to | |
23 | * handle SIGWINCH -- if the signal arrives during the select() call, then | |
24 | * we adjust the o_columns and o_lines variables, and fake a control-L. | |
25 | */ | |
26 | # include <sys/types.h> | |
27 | # include <sys/time.h> | |
28 | int ttyread(buf, len, time) | |
29 | char *buf; /* where to store the gotten characters */ | |
30 | int len; /* maximum number of characters to read */ | |
31 | int time; /* maximum time to allow for reading */ | |
32 | { | |
33 | fd_set rd; /* the file descriptors that we want to read from */ | |
34 | static tty; /* 'y' if reading from tty, or 'n' if not a tty */ | |
35 | int i; | |
36 | struct timeval t; | |
37 | struct timeval *tp; | |
38 | ||
39 | ||
40 | /* do we know whether this is a tty or not? */ | |
41 | if (!tty) | |
42 | { | |
43 | tty = (isatty(0) ? 'y' : 'n'); | |
44 | } | |
45 | ||
46 | /* compute the timeout value */ | |
47 | if (time) | |
48 | { | |
49 | t.tv_sec = time / 10; | |
50 | t.tv_usec = (time % 10) * 100000L; | |
51 | tp = &t; | |
52 | } | |
53 | else | |
54 | { | |
55 | tp = (struct timeval *)0; | |
56 | } | |
57 | ||
58 | /* loop until we get characters or a definite EOF */ | |
59 | for (;;) | |
60 | { | |
61 | if (tty == 'y') | |
62 | { | |
63 | /* wait until timeout or characters are available */ | |
64 | FD_ZERO(&rd); | |
65 | FD_SET(0, &rd); | |
66 | i = select(1, &rd, (fd_set *)0, (fd_set *)0, tp); | |
67 | } | |
68 | else | |
69 | { | |
70 | /* if reading from a file or pipe, never timeout! | |
71 | * (This also affects the way that EOF is detected) | |
72 | */ | |
73 | i = 1; | |
74 | } | |
75 | ||
76 | /* react accordingly... */ | |
77 | switch (i) | |
78 | { | |
79 | case -1: /* assume we got an EINTR because of SIGWINCH */ | |
80 | if (*o_lines != LINES || *o_columns != COLS) | |
81 | { | |
78ed81a3 | 82 | #ifndef CRUNCH |
83 | *o_nearscroll = | |
84 | #endif | |
15637ed4 RG |
85 | *o_lines = LINES; |
86 | *o_columns = COLS; | |
87 | #ifndef CRUNCH | |
88 | if (!wset) | |
89 | { | |
90 | *o_window = LINES - 1; | |
91 | } | |
92 | #endif | |
93 | if (mode != MODE_EX) | |
94 | { | |
95 | /* pretend the user hit ^L */ | |
96 | *buf = ctrl('L'); | |
97 | return 1; | |
98 | } | |
99 | } | |
100 | break; | |
101 | ||
102 | case 0: /* timeout */ | |
103 | return 0; | |
104 | ||
105 | default: /* characters available */ | |
106 | return read(0, buf, len); | |
107 | } | |
108 | } | |
109 | } | |
110 | # else | |
111 | ||
78ed81a3 | 112 | # if UNIXV || COH_386 |
113 | /* For System-V, we use VMIN/VTIME to implement the timeout. For no timeout, | |
114 | * VMIN should be 1 and VTIME should be 0; for timeout, VMIN should be 0 and | |
115 | * VTIME should be the timeout value. | |
15637ed4 RG |
116 | */ |
117 | # include <termio.h> | |
118 | int ttyread(buf, len, time) | |
119 | char *buf; /* where to store the gotten characters */ | |
120 | int len; /* maximum number of characters to read */ | |
121 | int time; /* maximum time to allow for reading */ | |
122 | { | |
123 | struct termio tio; | |
124 | int bytes; /* number of bytes actually read */ | |
125 | ||
126 | /* arrange for timeout */ | |
127 | ioctl(0, TCGETA, &tio); | |
128 | if (time) | |
129 | { | |
130 | tio.c_cc[VMIN] = 0; | |
131 | tio.c_cc[VTIME] = time; | |
132 | } | |
133 | else | |
134 | { | |
135 | tio.c_cc[VMIN] = 1; | |
136 | tio.c_cc[VTIME] = 0; | |
137 | } | |
138 | ioctl(0, TCSETA, &tio); | |
139 | ||
140 | /* Perform the read. Loop if EINTR error happens */ | |
78ed81a3 | 141 | while ((bytes = read(0, buf, (unsigned)len)) < 0) |
15637ed4 RG |
142 | { |
143 | /* probably EINTR error because a SIGWINCH was received */ | |
144 | if (*o_lines != LINES || *o_columns != COLS) | |
145 | { | |
146 | *o_lines = LINES; | |
147 | *o_columns = COLS; | |
148 | #ifndef CRUNCH | |
149 | if (!wset) | |
150 | { | |
78ed81a3 | 151 | *o_nearscroll = LINES; |
15637ed4 RG |
152 | *o_window = LINES - 1; |
153 | } | |
154 | #endif | |
155 | if (mode != MODE_EX) | |
156 | { | |
157 | /* pretend the user hit ^L */ | |
158 | *buf = ctrl('L'); | |
159 | return 1; | |
160 | } | |
161 | } | |
162 | } | |
163 | ||
164 | /* return the number of bytes read */ | |
165 | return bytes; | |
166 | ||
167 | /* NOTE: The terminal may be left in a timeout-mode after this function | |
168 | * returns. This shouldn't be a problem since Elvis *NEVER* tries to | |
169 | * read from the keyboard except through this function. | |
170 | */ | |
171 | } | |
172 | ||
173 | # else /* any other version of UNIX, assume it is V7 compatible */ | |
174 | ||
175 | /* For V7 UNIX (including Minix) we set an alarm() before doing a blocking | |
176 | * read(), and assume that the SIGALRM signal will cause the read() function | |
177 | * to give up. | |
178 | */ | |
179 | ||
180 | #include <setjmp.h> | |
181 | ||
182 | static jmp_buf env; | |
183 | ||
184 | /*ARGSUSED*/ | |
78ed81a3 | 185 | SIGTYPE dummy(signo) |
15637ed4 RG |
186 | int signo; |
187 | { | |
188 | longjmp(env, 1); | |
189 | } | |
190 | int ttyread(buf, len, time) | |
191 | char *buf; /* where to store the gotten characters */ | |
192 | int len; /* maximum number of characters to read */ | |
193 | int time; /* maximum time to allow for reading */ | |
194 | { | |
195 | /* arrange for timeout */ | |
15637ed4 | 196 | signal(SIGALRM, dummy); |
15637ed4 RG |
197 | alarm(time); |
198 | ||
199 | /* perform the blocking read */ | |
200 | if (setjmp(env) == 0) | |
201 | { | |
78ed81a3 | 202 | len = read(0, buf, (unsigned)len); |
15637ed4 RG |
203 | } |
204 | else /* I guess we timed out */ | |
205 | { | |
206 | len = 0; | |
207 | } | |
208 | ||
209 | /* cancel the alarm */ | |
210 | signal(SIGALRM, dummy); /* <-- to work around a bug in Minix */ | |
211 | alarm(0); | |
212 | ||
213 | /* return the number of bytes read */ | |
214 | if (len < 0) | |
215 | len = 0; | |
216 | return len; | |
217 | } | |
218 | ||
78ed81a3 | 219 | # endif /* M_SYSV */ |
15637ed4 RG |
220 | # endif /* !BSD */ |
221 | ||
222 | #endif /* ANY_UNIX */ |