misc/getttyent.c

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