usr/src/lib/libbc/libc/gen/common/getttyent.c

   1 /*
   2  * Copyright (c) 1985 Regents of the University of California.
   3  * All rights reserved.  The Berkeley software License Agreement
   4  * specifies the terms and conditions for redistribution.
   5  */
   6
   7 #pragma ident   "%Z%%M% %I%     %E% SMI"
   8
   9
  10 #include <stdio.h>
  11 #include <strings.h>
  12 #include <ttyent.h>
  13
  14 static char *TTYFILE = "/etc/ttytab";
  15 #define LINE 256
  16 static struct _ttyentjunk {
  17         char    zapchar;
  18         FILE    *tf;
  19         char    line[LINE];
  20         struct  ttyent tty;
  21 } *__ttyentjunk, *_ttyentjunk(void);
  22
  23 static struct _ttyentjunk *
  24 _ttyentjunk(void)
  25 {
  26
  27         if (__ttyentjunk == 0)
  28                 __ttyentjunk = (struct _ttyentjunk *)calloc(1, sizeof (struct _ttyentjunk));
  29         return (__ttyentjunk);
  30 }
  31
  32 void
  33 setttyent(void)
  34 {
  35         struct _ttyentjunk *t = _ttyentjunk();
  36
  37         if (t == 0)
  38                 return;
  39         if (t->tf == NULL)
  40                 t->tf = fopen(TTYFILE, "r");
  41         else
  42                 rewind(t->tf);
  43 }
  44
  45 void
  46 endttyent(void)
  47 {
  48         struct _ttyentjunk *t = _ttyentjunk();
  49
  50         if (t == 0)
  51                 return;
  52         if (t->tf != NULL) {
  53                 (void) fclose(t->tf);
  54                 t->tf = NULL;
  55         }
  56 }
  57
  58 #define QUOTED  1
  59
  60 /*
  61  * Skip over the current field, removing quotes,
  62  * and return a pointer to the next field.
  63  */
  64 static char *
  65 skip(char *p)
  66 {
  67         struct _ttyentjunk *t = _ttyentjunk();
  68         char *cp = p;
  69         int c;
  70         int q = 0;
  71
  72         if (t == 0)
  73                 return (0);
  74         for (; (c = *p) != '\0'; p++) {
  75                 if (c == '"') {
  76                         q ^= QUOTED;    /* obscure, but nice */
  77                         continue;
  78                 }
  79                 if (q == QUOTED && *p == '\\' && *(p+1) == '"')
  80                         p++;
  81                 *cp++ = *p;
  82                 if (q == QUOTED)
  83                         continue;
  84                 if (c == '#') {
  85                         t->zapchar = c;
  86                         *p = 0;
  87                         break;
  88                 }
  89                 if (c == '\t' || c == ' ' || c == '\n') {
  90                         t->zapchar = c;
  91                         *p++ = 0;
  92                         while ((c = *p) == '\t' || c == ' ' || c == '\n')
  93                                 p++;
  94                         break;
  95                 }
  96         }
  97         *--cp = '\0';
  98         return (p);
  99 }
 100
 101 static char *
 102 value(char *p)
 103 {
 104         if ((p = index(p,'=')) == 0)
 105                 return (NULL);
 106         p++;                    /* get past the = sign */
 107         return (p);
 108 }
 109
 110 struct ttyent *
 111 getttyent(void)
 112 {
 113         struct _ttyentjunk *t = _ttyentjunk();
 114         char *p;
 115         int c;
 116
 117         if (t == 0)
 118                 return (NULL);
 119         if (t->tf == NULL) {
 120                 if ((t->tf = fopen(TTYFILE, "r")) == NULL)
 121                         return (NULL);
 122         }
 123         do {
 124                 p = fgets(t->line, LINE, t->tf);
 125                 if (p == NULL)
 126                         return (NULL);
 127                 while ((c = *p) == '\t' || c == ' ' || c == '\n')
 128                         p++;
 129         } while (c == '\0' || c == '#');
 130         t->zapchar = 0;
 131         t->tty.ty_name = p;
 132         p = skip(p);
 133         t->tty.ty_getty = p;
 134         p = skip(p);
 135         t->tty.ty_type = p;
 136         p = skip(p);
 137         t->tty.ty_status = 0;
 138         t->tty.ty_window = NULL;
 139         for (; *p; p = skip(p)) {
 140 #define space(x) ((c = p[x]) == ' ' || c == '\t' || c == '\n')
 141                 if (strncmp(p, "on", 2) == 0 && space(2))
 142                         t->tty.ty_status |= TTY_ON;
 143                 else if (strncmp(p, "off", 3) == 0 && space(3))
 144                         t->tty.ty_status &= ~TTY_ON;
 145                 else if (strncmp(p, "secure", 6) == 0 && space(6))
 146                         t->tty.ty_status |= TTY_SECURE;
 147                 else if (strncmp(p, "local", 5) == 0 && space(5))
 148                         t->tty.ty_status |= TTY_LOCAL;
 149                 else if (strncmp(p, "window=", 7) == 0)
 150                         t->tty.ty_window = value(p);
 151                 else
 152                         break;
 153         }
 154         if (t->zapchar == '#' || *p == '#')
 155                 while ((c = *++p) == ' ' || c == '\t')
 156                         ;
 157         t->tty.ty_comment = p;
 158         if (*p == 0)
 159                 t->tty.ty_comment = 0;
 160         if (p = index(p, '\n'))
 161                 *p = '\0';
 162         return (&t->tty);
 163 }