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 static char zapchar;
  44 static FILE *tf;
  45
  46 struct ttyent *
  47 getttynam(tty)
  48         const char *tty;
  49 {
  50         register struct ttyent *t;
  51
  52         setttyent();
  53         while (t = getttyent())
  54                 if (!strcmp(tty, t->ty_name))
  55                         break;
  56         endttyent();
  57         return (t);
  58 }
  59
  60 static char *skip __P((char *)) internal_function;
  61 static char *value __P((char *)) internal_function;
  62
  63 struct ttyent *
  64 getttyent()
  65 {
  66         static struct ttyent tty;
  67         register int c;
  68         register char *p;
  69 #define MAXLINELENGTH   100
  70         static char line[MAXLINELENGTH];
  71
  72         if (!tf && !setttyent())
  73                 return (NULL);
  74         flockfile (tf);
  75         for (;;) {
  76                 if (!fgets_unlocked(p = line, sizeof(line), tf)) {
  77                         funlockfile (tf);
  78                         return (NULL);
  79                 }
  80                 /* skip lines that are too big */
  81                 if (!index(p, '\n')) {
  82                         while ((c = getc_unlocked(tf)) != '\n' && c != EOF)
  83                                 ;
  84                         continue;
  85                 }
  86                 while (isspace(*p))
  87                         ++p;
  88                 if (*p && *p != '#')
  89                         break;
  90         }
  91         funlockfile(tf);
  92
  93         zapchar = 0;
  94         tty.ty_name = p;
  95         p = skip(p);
  96         if (!*(tty.ty_getty = p))
  97                 tty.ty_getty = tty.ty_type = NULL;
  98         else {
  99                 p = skip(p);
 100                 if (!*(tty.ty_type = p))
 101                         tty.ty_type = NULL;
 102                 else
 103                         p = skip(p);
 104         }
 105         tty.ty_status = 0;
 106         tty.ty_window = NULL;
 107
 108 #define scmp(e) !strncmp(p, e, sizeof(e) - 1) && isspace(p[sizeof(e) - 1])
 109 #define vcmp(e) !strncmp(p, e, sizeof(e) - 1) && p[sizeof(e) - 1] == '='
 110         for (; *p; p = skip(p)) {
 111                 if (scmp(_TTYS_OFF))
 112                         tty.ty_status &= ~TTY_ON;
 113                 else if (scmp(_TTYS_ON))
 114                         tty.ty_status |= TTY_ON;
 115                 else if (scmp(_TTYS_SECURE))
 116                         tty.ty_status |= TTY_SECURE;
 117                 else if (vcmp(_TTYS_WINDOW))
 118                         tty.ty_window = value(p);
 119                 else
 120                         break;
 121         }
 122
 123         if (zapchar == '#' || *p == '#')
 124                 while ((c = *++p) == ' ' || c == '\t')
 125                         ;
 126         tty.ty_comment = p;
 127         if (*p == 0)
 128                 tty.ty_comment = 0;
 129         if (p = index(p, '\n'))
 130                 *p = '\0';
 131         return (&tty);
 132 }
 133
 134 #define QUOTED  1
 135
 136 /*
 137  * Skip over the current field, removing quotes, and return a pointer to
 138  * the next field.
 139  */
 140 static char *
 141 internal_function
 142 skip(p)
 143         register char *p;
 144 {
 145         register char *t;
 146         register int c, q;
 147
 148         for (q = 0, t = p; (c = *p) != '\0'; p++) {
 149                 if (c == '"') {
 150                         q ^= QUOTED;    /* obscure, but nice */
 151                         continue;
 152                 }
 153                 if (q == QUOTED && *p == '\\' && *(p+1) == '"')
 154                         p++;
 155                 *t++ = *p;
 156                 if (q == QUOTED)
 157                         continue;
 158                 if (c == '#') {
 159                         zapchar = c;
 160                         *p = 0;
 161                         break;
 162                 }
 163                 if (c == '\t' || c == ' ' || c == '\n') {
 164                         zapchar = c;
 165                         *p++ = 0;
 166                         while ((c = *p) == '\t' || c == ' ' || c == '\n')
 167                                 p++;
 168                         break;
 169                 }
 170         }
 171         *--t = '\0';
 172         return (p);
 173 }
 174
 175 static char *
 176 internal_function
 177 value(p)
 178         register char *p;
 179 {
 180
 181         return ((p = index(p, '=')) ? ++p : NULL);
 182 }
 183
 184 int
 185 setttyent()
 186 {
 187
 188         if (tf) {
 189                 (void)rewind(tf);
 190                 return (1);
 191         } else if (tf = fopen(_PATH_TTYS, "r"))
 192                 return (1);
 193         return (0);
 194 }
 195
 196 int
 197 endttyent()
 198 {
 199         int rval;
 200
 201         if (tf) {
 202                 rval = !(fclose(tf) == EOF);
 203                 tf = NULL;
 204                 return (rval);
 205         }
 206         return (1);
 207 }