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

/*
* Copyright (c) 1989 The Regents of the University of California.
* All rights reserved.
*
* %sccs.include.redist.c%
*/

#if defined(LIBC_SCCS) && !defined(lint)
static char sccsid[] = "@(#)getttyent.c 5.8 (Berkeley) %G%";
#endif /* LIBC_SCCS and not lint */

#include <ttyent.h>
#include <stdio.h>
#include <ctype.h>
#include <string.h>

static char zapchar;
static FILE *tf;

struct ttyent *
getttynam(tty)
       char *tty;
{
       register struct ttyent *t;

       setttyent();
       while (t = getttyent())
               if (!strcmp(tty, t->ty_name))
                       break;
       return(t);
}

struct ttyent *
getttyent()
{
       static struct ttyent tty;
       register int c;
       register char *p;
#define MAXLINELENGTH   100
       static char line[MAXLINELENGTH];
       char *skip(), *value();

       if (!tf && !setttyent())
               return(NULL);
       for (;;) {
               if (!fgets(p = line, sizeof(line), tf))
                       return(NULL);
               /* skip lines that are too big */
               if (!index(p, '\n')) {
                       while ((c = getc(tf)) != '\n' && c != EOF)
                               ;
                       continue;
               }
               while (isspace(*p))
                       ++p;
               if (*p && *p != '#')
                       break;
       }

       zapchar = 0;
       tty.ty_name = p;
       p = skip(p);
       if (!*(tty.ty_getty = p))
               tty.ty_getty = tty.ty_type = NULL;
       else {
               p = skip(p);
               if (!*(tty.ty_type = p))
                       tty.ty_type = NULL;
               else
                       p = skip(p);
       }
       tty.ty_status = 0;
       tty.ty_window = NULL;

#define scmp(e) !strncmp(p, e, sizeof(e) - 1) && isspace(p[sizeof(e) - 1])
#define vcmp(e) !strncmp(p, e, sizeof(e) - 1) && p[sizeof(e) - 1] == '='
       for (; *p; p = skip(p)) {
               if (scmp(_TTYS_OFF))
                       tty.ty_status &= ~TTY_ON;
               else if (scmp(_TTYS_ON))
                       tty.ty_status |= TTY_ON;
               else if (scmp(_TTYS_SECURE))
                       tty.ty_status |= TTY_SECURE;
               else if (vcmp(_TTYS_WINDOW))
                       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);
}

#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;
       register int c, q;

       for (q = 0, t = p; (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;
{
       return((p = index(p, '=')) ? ++p : NULL);
}

setttyent()
{
       if (tf) {
               (void)rewind(tf);
               return(1);
       } else if (tf = fopen(_PATH_TTYS, "r"))
               return(1);
       return(0);
}

endttyent()
{
       int rval;

       if (tf) {
               rval = !(fclose(tf) == EOF);
               tf = NULL;
               return(rval);
       }
       return(1);
}