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vars.c revision 1.6 
      1 /*	$NetBSD: vars.c,v 1.6 1998/10/08 17:36:56 wsanchez Exp $	*/
      2 
      3 /*
      4  * Copyright (c) 1980, 1993
      5  *	The Regents of the University of California.  All rights reserved.
      6  *
      7  * Redistribution and use in source and binary forms, with or without
      8  * modification, are permitted provided that the following conditions
      9  * are met:
     10  * 1. Redistributions of source code must retain the above copyright
     11  *    notice, this list of conditions and the following disclaimer.
     12  * 2. Redistributions in binary form must reproduce the above copyright
     13  *    notice, this list of conditions and the following disclaimer in the
     14  *    documentation and/or other materials provided with the distribution.
     15  * 3. All advertising materials mentioning features or use of this software
     16  *    must display the following acknowledgement:
     17  *	This product includes software developed by the University of
     18  *	California, Berkeley and its contributors.
     19  * 4. Neither the name of the University nor the names of its contributors
     20  *    may be used to endorse or promote products derived from this software
     21  *    without specific prior written permission.
     22  *
     23  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     24  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     25  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     26  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     27  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     28  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     29  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     30  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     31  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     32  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     33  * SUCH DAMAGE.
     34  */
     35 
     36 #include <sys/cdefs.h>
     37 #ifndef lint
     38 #if 0
     39 static char sccsid[] = "@(#)vars.c	8.1 (Berkeley) 6/6/93";
     40 #else
     41 __RCSID("$NetBSD: vars.c,v 1.6 1998/10/08 17:36:56 wsanchez Exp $");
     42 #endif
     43 #endif /* not lint */
     44 
     45 #include "rcv.h"
     46 #include "extern.h"
     47 
     48 /*
     49  * Mail -- a mail program
     50  *
     51  * Variable handling stuff.
     52  */
     53 
     54 /*
     55  * Assign a value to a variable.
     56  */
     57 void
     58 assign(name, value)
     59 	char name[], value[];
     60 {
     61 	struct var *vp;
     62 	int h;
     63 
     64 	h = hash(name);
     65 	vp = lookup(name);
     66 	if (vp == NOVAR) {
     67 		vp = (struct var *) calloc(sizeof *vp, 1);
     68 		vp->v_name = vcopy(name);
     69 		vp->v_link = variables[h];
     70 		variables[h] = vp;
     71 	}
     72 	else
     73                 v_free(vp->v_value);
     74 	vp->v_value = vcopy(value);
     75 }
     76 
     77 /*
     78  * Free up a variable string.  We do not bother to allocate
     79  * strings whose value is "" since they are expected to be frequent.
     80  * Thus, we cannot free same!
     81  */
     82 void
     83 v_free(cp)
     84 	char *cp;
     85 {
     86 	if (*cp)
     87 		free(cp);
     88 }
     89 
     90 /*
     91  * Copy a variable value into permanent (ie, not collected after each
     92  * command) space.  Do not bother to alloc space for ""
     93  */
     94 
     95 char *
     96 vcopy(str)
     97 	char str[];
     98 {
     99 	char *new;
    100 	unsigned len;
    101 
    102 	if (*str == '\0')
    103 		return "";
    104 	len = strlen(str) + 1;
    105 	if ((new = malloc(len)) == NULL)
    106 		errx(1, "Out of memory");
    107 	memmove(new, str, (int) len);
    108 	return new;
    109 }
    110 
    111 /*
    112  * Get the value of a variable and return it.
    113  * Look in the environment if its not available locally.
    114  */
    115 
    116 char *
    117 value(name)
    118 	char name[];
    119 {
    120 	struct var *vp;
    121 
    122 	if ((vp = lookup(name)) == NOVAR)
    123 		return(getenv(name));
    124 	return(vp->v_value);
    125 }
    126 
    127 /*
    128  * Locate a variable and return its variable
    129  * node.
    130  */
    131 
    132 struct var *
    133 lookup(name)
    134 	char name[];
    135 {
    136 	struct var *vp;
    137 
    138 	for (vp = variables[hash(name)]; vp != NOVAR; vp = vp->v_link)
    139 		if (*vp->v_name == *name && equal(vp->v_name, name))
    140 			return(vp);
    141 	return(NOVAR);
    142 }
    143 
    144 /*
    145  * Locate a group name and return it.
    146  */
    147 
    148 struct grouphead *
    149 findgroup(name)
    150 	char name[];
    151 {
    152 	struct grouphead *gh;
    153 
    154 	for (gh = groups[hash(name)]; gh != NOGRP; gh = gh->g_link)
    155 		if (*gh->g_name == *name && equal(gh->g_name, name))
    156 			return(gh);
    157 	return(NOGRP);
    158 }
    159 
    160 /*
    161  * Print a group out on stdout
    162  */
    163 void
    164 printgroup(name)
    165 	char name[];
    166 {
    167 	struct grouphead *gh;
    168 	struct group *gp;
    169 
    170 	if ((gh = findgroup(name)) == NOGRP) {
    171 		printf("\"%s\": not a group\n", name);
    172 		return;
    173 	}
    174 	printf("%s\t", gh->g_name);
    175 	for (gp = gh->g_list; gp != NOGE; gp = gp->ge_link)
    176 		printf(" %s", gp->ge_name);
    177 	putchar('\n');
    178 }
    179 
    180 /*
    181  * Hash the passed string and return an index into
    182  * the variable or group hash table.
    183  */
    184 int
    185 hash(name)
    186 	char *name;
    187 {
    188 	int h = 0;
    189 
    190 	while (*name) {
    191 		h <<= 2;
    192 		h += *name++;
    193 	}
    194 	if (h < 0 && (h = -h) < 0)
    195 		h = 0;
    196 	return (h % HSHSIZE);
    197 }
    198