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vars.c revision 1.4 
      1 /*	$NetBSD: vars.c,v 1.4 1996/06/08 19:48:45 christos 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 #ifndef lint
     37 #if 0
     38 static char sccsid[] = "@(#)vars.c	8.1 (Berkeley) 6/6/93";
     39 #else
     40 static char rcsid[] = "$NetBSD: vars.c,v 1.4 1996/06/08 19:48:45 christos Exp $";
     41 #endif
     42 #endif /* not lint */
     43 
     44 #include "rcv.h"
     45 #include "extern.h"
     46 
     47 /*
     48  * Mail -- a mail program
     49  *
     50  * Variable handling stuff.
     51  */
     52 
     53 /*
     54  * Assign a value to a variable.
     55  */
     56 void
     57 assign(name, value)
     58 	char name[], value[];
     59 {
     60 	register struct var *vp;
     61 	register int h;
     62 
     63 	h = hash(name);
     64 	vp = lookup(name);
     65 	if (vp == NOVAR) {
     66 		vp = (struct var *) calloc(sizeof *vp, 1);
     67 		vp->v_name = vcopy(name);
     68 		vp->v_link = variables[h];
     69 		variables[h] = vp;
     70 	}
     71 	else
     72 		vfree(vp->v_value);
     73 	vp->v_value = vcopy(value);
     74 }
     75 
     76 /*
     77  * Free up a variable string.  We do not bother to allocate
     78  * strings whose value is "" since they are expected to be frequent.
     79  * Thus, we cannot free same!
     80  */
     81 void
     82 vfree(cp)
     83 	char *cp;
     84 {
     85 	if (*cp)
     86 		free(cp);
     87 }
     88 
     89 /*
     90  * Copy a variable value into permanent (ie, not collected after each
     91  * command) space.  Do not bother to alloc space for ""
     92  */
     93 
     94 char *
     95 vcopy(str)
     96 	char str[];
     97 {
     98 	char *new;
     99 	unsigned len;
    100 
    101 	if (*str == '\0')
    102 		return "";
    103 	len = strlen(str) + 1;
    104 	if ((new = malloc(len)) == NULL)
    105 		panic("Out of memory");
    106 	bcopy(str, new, (int) len);
    107 	return new;
    108 }
    109 
    110 /*
    111  * Get the value of a variable and return it.
    112  * Look in the environment if its not available locally.
    113  */
    114 
    115 char *
    116 value(name)
    117 	char name[];
    118 {
    119 	register struct var *vp;
    120 
    121 	if ((vp = lookup(name)) == NOVAR)
    122 		return(getenv(name));
    123 	return(vp->v_value);
    124 }
    125 
    126 /*
    127  * Locate a variable and return its variable
    128  * node.
    129  */
    130 
    131 struct var *
    132 lookup(name)
    133 	register char name[];
    134 {
    135 	register struct var *vp;
    136 
    137 	for (vp = variables[hash(name)]; vp != NOVAR; vp = vp->v_link)
    138 		if (*vp->v_name == *name && equal(vp->v_name, name))
    139 			return(vp);
    140 	return(NOVAR);
    141 }
    142 
    143 /*
    144  * Locate a group name and return it.
    145  */
    146 
    147 struct grouphead *
    148 findgroup(name)
    149 	register char name[];
    150 {
    151 	register struct grouphead *gh;
    152 
    153 	for (gh = groups[hash(name)]; gh != NOGRP; gh = gh->g_link)
    154 		if (*gh->g_name == *name && equal(gh->g_name, name))
    155 			return(gh);
    156 	return(NOGRP);
    157 }
    158 
    159 /*
    160  * Print a group out on stdout
    161  */
    162 void
    163 printgroup(name)
    164 	char name[];
    165 {
    166 	register struct grouphead *gh;
    167 	register struct group *gp;
    168 
    169 	if ((gh = findgroup(name)) == NOGRP) {
    170 		printf("\"%s\": not a group\n", name);
    171 		return;
    172 	}
    173 	printf("%s\t", gh->g_name);
    174 	for (gp = gh->g_list; gp != NOGE; gp = gp->ge_link)
    175 		printf(" %s", gp->ge_name);
    176 	putchar('\n');
    177 }
    178 
    179 /*
    180  * Hash the passed string and return an index into
    181  * the variable or group hash table.
    182  */
    183 int
    184 hash(name)
    185 	register char *name;
    186 {
    187 	register h = 0;
    188 
    189 	while (*name) {
    190 		h <<= 2;
    191 		h += *name++;
    192 	}
    193 	if (h < 0 && (h = -h) < 0)
    194 		h = 0;
    195 	return (h % HSHSIZE);
    196 }
    197