1: /*
    2:  * Copyright (c) 1989, 1993
    3:  *      The Regents of the University of California.  All rights reserved.
    4:  *
    5:  * Redistribution and use in source and binary forms, with or without
    6:  * modification, are permitted provided that the following conditions
    7:  * are met:
    8:  * 1. Redistributions of source code must retain the above copyright
    9:  *    notice, this list of conditions and the following disclaimer.
   10:  * 2. Redistributions in binary form must reproduce the above copyright
   11:  *    notice, this list of conditions and the following disclaimer in the
   12:  *    documentation and/or other materials provided with the distribution.
   13:  * 4. Neither the name of the University nor the names of its contributors
   14:  *    may be used to endorse or promote products derived from this software
   15:  *    without specific prior written permission.
   16:  *
   17:  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
   18:  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
   19:  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
   20:  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
   21:  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
   22:  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
   23:  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
   24:  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
   25:  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
   26:  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
   27:  * SUCH DAMAGE.
   28:  */
   29: 
   30: #if defined(LIBC_SCCS) && !defined(lint)
   31: static char sccsid[] = "@(#)getttyent.c 8.1 (Berkeley) 6/4/93";
   32: #endif /* LIBC_SCCS and not lint */
   33: 
   34: #include <ttyent.h>
   35: #include <stdio.h>
   36: #include <stdio_ext.h>
   37: #include <ctype.h>
   38: #include <string.h>
   39: 
   40: #ifdef USE_IN_LIBIO
   41: # define flockfile(s) _IO_flockfile (s)
   42: # define funlockfile(s) _IO_funlockfile (s)
   43: #endif
   44: 
   45: static char zapchar;
   46: static FILE *tf;
   47: 
   48: struct ttyent *
   49: getttynam(tty)
   50:         const char *tty;
   51: {
   52:         register struct ttyent *t;
   53: 
   54:         setttyent();
   55:         while ((t = getttyent()))
   56:                 if (!strcmp(tty, t->ty_name))
   57:                         break;
   58:         endttyent();
   59:         return (t);
   60: }
   61: 
   62: static char *skip (char *) __THROW internal_function;
   63: static char *value (char *) __THROW internal_function;
   64: 
   65: struct ttyent *
   66: getttyent()
   67: {
   68:         static struct ttyent tty;
   69:         register int c;
   70:         register char *p;
   71: #define MAXLINELENGTH   100
   72:         static char line[MAXLINELENGTH];
   73: 
   74:         if (!tf && !setttyent())
   75:                 return (NULL);
   76:         flockfile (tf);
   77:         for (;;) {
   78:                 if (!fgets_unlocked(p = line, sizeof(line), tf)) {
   79:                         funlockfile (tf);
   80:                         return (NULL);
   81:                 }
   82:                 /* skip lines that are too big */
   83:                 if (!index(p, '\n')) {
   84:                         while ((c = getc_unlocked(tf)) != '\n' && c != EOF)
   85:                                 ;
   86:                         continue;
   87:                 }
   88:                 while (isspace(*p))
   89:                         ++p;
   90:                 if (*p && *p != '#')
   91:                         break;
   92:         }
   93: 
   94:         zapchar = 0;
   95:         tty.ty_name = p;
   96:         p = skip(p);
   97:         if (!*(tty.ty_getty = p))
   98:                 tty.ty_getty = tty.ty_type = NULL;
   99:         else {
  100:                 p = skip(p);
  101:                 if (!*(tty.ty_type = p))
  102:                         tty.ty_type = NULL;
  103:                 else
  104:                         p = skip(p);
  105:         }
  106:         tty.ty_status = 0;
  107:         tty.ty_window = NULL;
  108: 
  109: #define scmp(e) !strncmp(p, e, sizeof(e) - 1) && isspace(p[sizeof(e) - 1])
  110: #define vcmp(e) !strncmp(p, e, sizeof(e) - 1) && p[sizeof(e) - 1] == '='
  111:         for (; *p; p = skip(p)) {
  112:                 if (scmp(_TTYS_OFF))
  113:                         tty.ty_status &= ~TTY_ON;
  114:                 else if (scmp(_TTYS_ON))
  115:                         tty.ty_status |= TTY_ON;
  116:                 else if (scmp(_TTYS_SECURE))
  117:                         tty.ty_status |= TTY_SECURE;
  118:                 else if (vcmp(_TTYS_WINDOW))
  119:                         tty.ty_window = value(p);
  120:                 else
  121:                         break;
  122:         }
  123:         /* We can release the lock only here since `zapchar' is global.  */
  124:         funlockfile(tf);
  125: 
  126:         if (zapchar == '#' || *p == '#')
  127:                 while ((c = *++p) == ' ' || c == '\t')
  128:                         ;
  129:         tty.ty_comment = p;
  130:         if (*p == 0)
  131:                 tty.ty_comment = 0;
  132:         if ((p = index(p, '\n')))
  133:                 *p = '\0';
  134:         return (&tty);
  135: }
  136: libc_hidden_def (getttyent)
  137: 
  138: #define QUOTED  1
  139: 
  140: /*
  141:  * Skip over the current field, removing quotes, and return a pointer to
  142:  * the next field.
  143:  */
  144: static char *
  145: internal_function
  146: skip(p)
  147:         register char *p;
  148: {
  149:         register char *t;
  150:         register int c, q;
  151: 
  152:         for (q = 0, t = p; (c = *p) != '\0'; p++) {
  153:                 if (c == '"') {
  154:                         q ^= QUOTED; /* obscure, but nice */
  155:                         continue;
  156:                 }
  157:                 if (q == QUOTED && *p == '\\' && *(p+1) == '"')
  158:                         p++;
  159:                 *t++ = *p;
  160:                 if (q == QUOTED)
  161:                         continue;
  162:                 if (c == '#') {
  163:                         zapchar = c;
  164:                         *p = 0;
  165:                         break;
  166:                 }
  167:                 if (c == '\t' || c == ' ' || c == '\n') {
  168:                         zapchar = c;
  169:                         *p++ = 0;
  170:                         while ((c = *p) == '\t' || c == ' ' || c == '\n')
  171:                                 p++;
  172:                         break;
  173:                 }
  174:         }
  175:         *--t = '\0';
  176:         return (p);
  177: }
  178: 
  179: static char *
  180: internal_function
  181: value(p)
  182:         register char *p;
  183: {
  184: 
  185:         return ((p = index(p, '=')) ? ++p : NULL);
  186: }
  187: 
  188: int
  189: setttyent()
  190: {
  191: 
  192:         if (tf) {
  193:                 (void)rewind(tf);
  194:                 return (1);
  195:         } else if ((tf = fopen(_PATH_TTYS, "rc"))) {
  196:                 /* We do the locking ourselves.  */
  197:                 __fsetlocking (tf, FSETLOCKING_BYCALLER);
  198:                 return (1);
  199:         }
  200:         return (0);
  201: }
  202: libc_hidden_def (setttyent)
  203: 
  204: int
  205: endttyent()
  206: {
  207:         int rval;
  208: 
  209:         if (tf) {
  210:                 rval = !(fclose(tf) == EOF);
  211:                 tf = NULL;
  212:                 return (rval);
  213:         }
  214:         return (1);
  215: }
  216: libc_hidden_def (endttyent)