glibc/misc/getttyent.c

214 lines
4.9 KiB
C

/*
* Copyright (c) 1989, 1993
* The Regents of the University of California. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#if defined(LIBC_SCCS) && !defined(lint)
static char sccsid[] = "@(#)getttyent.c 8.1 (Berkeley) 6/4/93";
#endif /* LIBC_SCCS and not lint */
#include <ttyent.h>
#include <stdio.h>
#include <stdio_ext.h>
#include <ctype.h>
#include <string.h>
#define flockfile(s) _IO_flockfile (s)
#define funlockfile(s) _IO_funlockfile (s)
static char zapchar;
static FILE *tf;
struct ttyent *
__getttynam (const char *tty)
{
struct ttyent *t;
__setttyent();
while ((t = __getttyent()))
if (!strcmp(tty, t->ty_name))
break;
__endttyent();
return (t);
}
weak_alias (__getttynam, getttynam)
static char *skip (char *) __THROW;
static char *value (char *) __THROW;
struct ttyent *
__getttyent (void)
{
static struct ttyent tty;
int c;
char *p;
#define MAXLINELENGTH 100
static char line[MAXLINELENGTH];
if (!tf && !__setttyent())
return (NULL);
flockfile (tf);
for (;;) {
if (!__fgets_unlocked(p = line, sizeof(line), tf)) {
funlockfile (tf);
return (NULL);
}
/* skip lines that are too big */
if (!strchr (p, '\n')) {
while ((c = getc_unlocked(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;
}
/* We can release the lock only here since `zapchar' is global. */
funlockfile(tf);
if (zapchar == '#' || *p == '#')
while ((c = *++p) == ' ' || c == '\t')
;
tty.ty_comment = p;
if (*p == 0)
tty.ty_comment = 0;
if ((p = strchr (p, '\n')))
*p = '\0';
return (&tty);
}
libc_hidden_def (__getttyent)
weak_alias (__getttyent, getttyent)
#define QUOTED 1
/*
* Skip over the current field, removing quotes, and return a pointer to
* the next field.
*/
static char *
skip (char *p)
{
char *t;
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 (char *p)
{
return ((p = strchr (p, '=')) ? ++p : NULL);
}
int
__setttyent (void)
{
if (tf) {
(void)rewind(tf);
return (1);
} else if ((tf = fopen(_PATH_TTYS, "rce"))) {
/* We do the locking ourselves. */
__fsetlocking (tf, FSETLOCKING_BYCALLER);
return (1);
}
return (0);
}
libc_hidden_def (__setttyent)
weak_alias (__setttyent, setttyent)
int
__endttyent (void)
{
int rval;
if (tf) {
rval = !(fclose(tf) == EOF);
tf = NULL;
return (rval);
}
return (1);
}
libc_hidden_def (__endttyent)
weak_alias (__endttyent, endttyent)