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