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getttyent.c revision 1.1.1.2 
      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 struct ttyent *
     61 getttyent()
     62 {
     63 	static struct ttyent tty;
     64 	register int c;
     65 	register char *p;
     66 #define	MAXLINELENGTH	100
     67 	static char line[MAXLINELENGTH];
     68 	static char *skip(), *value();
     69 
     70 	if (!tf && !setttyent())
     71 		return (NULL);
     72 	for (;;) {
     73 		if (!fgets(p = line, sizeof(line), tf))
     74 			return (NULL);
     75 		/* skip lines that are too big */
     76 		if (!index(p, '\n')) {
     77 			while ((c = getc(tf)) != '\n' && c != EOF)
     78 				;
     79 			continue;
     80 		}
     81 		while (isspace(*p))
     82 			++p;
     83 		if (*p && *p != '#')
     84 			break;
     85 	}
     86 
     87 	zapchar = 0;
     88 	tty.ty_name = p;
     89 	p = skip(p);
     90 	if (!*(tty.ty_getty = p))
     91 		tty.ty_getty = tty.ty_type = NULL;
     92 	else {
     93 		p = skip(p);
     94 		if (!*(tty.ty_type = p))
     95 			tty.ty_type = NULL;
     96 		else
     97 			p = skip(p);
     98 	}
     99 	tty.ty_status = 0;
    100 	tty.ty_window = NULL;
    101 
    102 #define	scmp(e)	!strncmp(p, e, sizeof(e) - 1) && isspace(p[sizeof(e) - 1])
    103 #define	vcmp(e)	!strncmp(p, e, sizeof(e) - 1) && p[sizeof(e) - 1] == '='
    104 	for (; *p; p = skip(p)) {
    105 		if (scmp(_TTYS_OFF))
    106 			tty.ty_status &= ~TTY_ON;
    107 		else if (scmp(_TTYS_ON))
    108 			tty.ty_status |= TTY_ON;
    109 		else if (scmp(_TTYS_SECURE))
    110 			tty.ty_status |= TTY_SECURE;
    111 		else if (vcmp(_TTYS_WINDOW))
    112 			tty.ty_window = value(p);
    113 		else
    114 			break;
    115 	}
    116 
    117 	if (zapchar == '#' || *p == '#')
    118 		while ((c = *++p) == ' ' || c == '\t')
    119 			;
    120 	tty.ty_comment = p;
    121 	if (*p == 0)
    122 		tty.ty_comment = 0;
    123 	if (p = index(p, '\n'))
    124 		*p = '\0';
    125 	return (&tty);
    126 }
    127 
    128 #define	QUOTED	1
    129 
    130 /*
    131  * Skip over the current field, removing quotes, and return a pointer to
    132  * the next field.
    133  */
    134 static char *
    135 skip(p)
    136 	register char *p;
    137 {
    138 	register char *t;
    139 	register int c, q;
    140 
    141 	for (q = 0, t = p; (c = *p) != '\0'; p++) {
    142 		if (c == '"') {
    143 			q ^= QUOTED;	/* obscure, but nice */
    144 			continue;
    145 		}
    146 		if (q == QUOTED && *p == '\\' && *(p+1) == '"')
    147 			p++;
    148 		*t++ = *p;
    149 		if (q == QUOTED)
    150 			continue;
    151 		if (c == '#') {
    152 			zapchar = c;
    153 			*p = 0;
    154 			break;
    155 		}
    156 		if (c == '\t' || c == ' ' || c == '\n') {
    157 			zapchar = c;
    158 			*p++ = 0;
    159 			while ((c = *p) == '\t' || c == ' ' || c == '\n')
    160 				p++;
    161 			break;
    162 		}
    163 	}
    164 	*--t = '\0';
    165 	return (p);
    166 }
    167 
    168 static char *
    169 value(p)
    170 	register char *p;
    171 {
    172 
    173 	return ((p = index(p, '=')) ? ++p : NULL);
    174 }
    175 
    176 int
    177 setttyent()
    178 {
    179 
    180 	if (tf) {
    181 		(void)rewind(tf);
    182 		return (1);
    183 	} else if (tf = fopen(_PATH_TTYS, "r"))
    184 		return (1);
    185 	return (0);
    186 }
    187 
    188 int
    189 endttyent()
    190 {
    191 	int rval;
    192 
    193 	if (tf) {
    194 		rval = !(fclose(tf) == EOF);
    195 		tf = NULL;
    196 		return (rval);
    197 	}
    198 	return (1);
    199 }
    200