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