BSD 4_3 release

[unix-history] / usr / src / lib / libc / gen / getttyent.c

/*
* Copyright (c) 1985 Regents of the University of California.
* All rights reserved.  The Berkeley software License Agreement
* specifies the terms and conditions for redistribution.
*/

#if defined(LIBC_SCCS) && !defined(lint)
static char sccsid[] = "@(#)getttyent.c 5.4 (Berkeley) 5/19/86";
#endif LIBC_SCCS and not lint

#include <stdio.h>
#include <strings.h>
#include <ttyent.h>

static char TTYFILE[] = "/etc/ttys";
static char zapchar;
static FILE *tf = NULL;
#define LINE 256
static char line[LINE];
static struct ttyent tty;

setttyent()
{
       if (tf == NULL)
               tf = fopen(TTYFILE, "r");
       else
               rewind(tf);
}

endttyent()
{
       if (tf != NULL) {
               (void) fclose(tf);
               tf = NULL;
       }
}

#define QUOTED  1

/*
* Skip over the current field, removing quotes,
* and return a pointer to the next field.
*/
static char *
skip(p)
       register char *p;
{
       register char *t = p;
       register int c;
       register int q = 0;

       for (; (c = *p) != '\0'; p++) {
               if (c == '"') {
                       q ^= QUOTED;    /* obscure, but nice */
                       continue;
               }
               if (q == QUOTED && *p == '\\' && *(p+1) == '"')
                       p++;
               *t++ = *p;
               if (q == QUOTED)
                       continue;
               if (c == '#') {
                       zapchar = c;
                       *p = 0;
                       break;
               }
               if (c == '\t' || c == ' ' || c == '\n') {
                       zapchar = c;
                       *p++ = 0;
                       while ((c = *p) == '\t' || c == ' ' || c == '\n')
                               p++;
                       break;
               }
       }
       *--t = '\0';
       return (p);
}

static char *
value(p)
       register char *p;
{
       if ((p = index(p,'=')) == 0)
               return(NULL);
       p++;                    /* get past the = sign */
       return(p);
}

struct ttyent *
getttyent()
{
       register char *p;
       register int c;

       if (tf == NULL) {
               if ((tf = fopen(TTYFILE, "r")) == NULL)
                       return (NULL);
       }
       do {
               p = fgets(line, LINE, tf);
               if (p == NULL)
                       return (NULL);
               while ((c = *p) == '\t' || c == ' ' || c == '\n')
                       p++;
       } while (c == '\0' || c == '#');
       zapchar = 0;
       tty.ty_name = p;
       p = skip(p);
       tty.ty_getty = p;
       p = skip(p);
       tty.ty_type = p;
       p = skip(p);
       tty.ty_status = 0;
       tty.ty_window = NULL;
       for (; *p; p = skip(p)) {
#define space(x) ((c = p[x]) == ' ' || c == '\t' || c == '\n')
               if (strncmp(p, "on", 2) == 0 && space(2))
                       tty.ty_status |= TTY_ON;
               else if (strncmp(p, "off", 3) == 0 && space(3))
                       tty.ty_status &= ~TTY_ON;
               else if (strncmp(p, "secure", 6) == 0 && space(6))
                       tty.ty_status |= TTY_SECURE;
               else if (strncmp(p, "window=", 7) == 0)
                       tty.ty_window = value(p);
               else
                       break;
       }
       if (zapchar == '#' || *p == '#')
               while ((c = *++p) == ' ' || c == '\t')
                       ;
       tty.ty_comment = p;
       if (*p == 0)
               tty.ty_comment = 0;
       if (p = index(p, '\n'))
               *p = '\0';
       return(&tty);
}