| 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 | { |
| 82 | *o_lines = LINES; |
| 83 | *o_columns = COLS; |
| 84 | #ifndef CRUNCH |
| 85 | if (!wset) |
| 86 | { |
| 87 | *o_window = LINES - 1; |
| 88 | } |
| 89 | #endif |
| 90 | if (mode != MODE_EX) |
| 91 | { |
| 92 | /* pretend the user hit ^L */ |
| 93 | *buf = ctrl('L'); |
| 94 | return 1; |
| 95 | } |
| 96 | } |
| 97 | break; |
| 98 | |
| 99 | case 0: /* timeout */ |
| 100 | return 0; |
| 101 | |
| 102 | default: /* characters available */ |
| 103 | return read(0, buf, len); |
| 104 | } |
| 105 | } |
| 106 | } |
| 107 | # else |
| 108 | |
| 109 | # if M_SYSV |
| 110 | /* For System-V or Coherent, we use VMIN/VTIME to implement the timeout. |
| 111 | * For no timeout, VMIN should be 1 and VTIME should be 0; for timeout, |
| 112 | * VMIN should be 0 and VTIME should be the timeout value. |
| 113 | */ |
| 114 | # include <termio.h> |
| 115 | int ttyread(buf, len, time) |
| 116 | char *buf; /* where to store the gotten characters */ |
| 117 | int len; /* maximum number of characters to read */ |
| 118 | int time; /* maximum time to allow for reading */ |
| 119 | { |
| 120 | struct termio tio; |
| 121 | int bytes; /* number of bytes actually read */ |
| 122 | |
| 123 | /* arrange for timeout */ |
| 124 | ioctl(0, TCGETA, &tio); |
| 125 | if (time) |
| 126 | { |
| 127 | tio.c_cc[VMIN] = 0; |
| 128 | tio.c_cc[VTIME] = time; |
| 129 | } |
| 130 | else |
| 131 | { |
| 132 | tio.c_cc[VMIN] = 1; |
| 133 | tio.c_cc[VTIME] = 0; |
| 134 | } |
| 135 | ioctl(0, TCSETA, &tio); |
| 136 | |
| 137 | /* Perform the read. Loop if EINTR error happens */ |
| 138 | while ((bytes = read(0, buf, len)) < 0) |
| 139 | { |
| 140 | /* probably EINTR error because a SIGWINCH was received */ |
| 141 | if (*o_lines != LINES || *o_columns != COLS) |
| 142 | { |
| 143 | *o_lines = LINES; |
| 144 | *o_columns = COLS; |
| 145 | #ifndef CRUNCH |
| 146 | if (!wset) |
| 147 | { |
| 148 | *o_window = LINES - 1; |
| 149 | } |
| 150 | #endif |
| 151 | if (mode != MODE_EX) |
| 152 | { |
| 153 | /* pretend the user hit ^L */ |
| 154 | *buf = ctrl('L'); |
| 155 | return 1; |
| 156 | } |
| 157 | } |
| 158 | } |
| 159 | |
| 160 | /* return the number of bytes read */ |
| 161 | return bytes; |
| 162 | |
| 163 | /* NOTE: The terminal may be left in a timeout-mode after this function |
| 164 | * returns. This shouldn't be a problem since Elvis *NEVER* tries to |
| 165 | * read from the keyboard except through this function. |
| 166 | */ |
| 167 | } |
| 168 | |
| 169 | # else /* any other version of UNIX, assume it is V7 compatible */ |
| 170 | |
| 171 | /* For V7 UNIX (including Minix) we set an alarm() before doing a blocking |
| 172 | * read(), and assume that the SIGALRM signal will cause the read() function |
| 173 | * to give up. |
| 174 | */ |
| 175 | |
| 176 | #include <setjmp.h> |
| 177 | |
| 178 | static jmp_buf env; |
| 179 | |
| 180 | /*ARGSUSED*/ |
| 181 | int dummy(signo) |
| 182 | int signo; |
| 183 | { |
| 184 | longjmp(env, 1); |
| 185 | } |
| 186 | int ttyread(buf, len, time) |
| 187 | char *buf; /* where to store the gotten characters */ |
| 188 | int len; /* maximum number of characters to read */ |
| 189 | int time; /* maximum time to allow for reading */ |
| 190 | { |
| 191 | /* arrange for timeout */ |
| 192 | #if __GNUC__ |
| 193 | signal(SIGALRM, (void (*)()) dummy); |
| 194 | #else |
| 195 | signal(SIGALRM, dummy); |
| 196 | #endif |
| 197 | alarm(time); |
| 198 | |
| 199 | /* perform the blocking read */ |
| 200 | if (setjmp(env) == 0) |
| 201 | { |
| 202 | len = read(0, buf, len); |
| 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 | |
| 219 | # endif /* !(M_SYSV || COHERENT) */ |
| 220 | # endif /* !BSD */ |
| 221 | |
| 222 | #endif /* ANY_UNIX */ |