Home | History | Annotate | Line # | Download | only in mail
vars.c revision 1.2 
      1 /*
      2  * Copyright (c) 1980 Regents of the University of California.
      3  * 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 #ifndef lint
     35 /*static char sccsid[] = "from: @(#)vars.c	5.6 (Berkeley) 6/1/90";*/
     36 static char rcsid[] = "$Id: vars.c,v 1.2 1993/08/01 18:12:52 mycroft Exp $";
     37 #endif /* not lint */
     38 
     39 #include "rcv.h"
     40 
     41 /*
     42  * Mail -- a mail program
     43  *
     44  * Variable handling stuff.
     45  */
     46 
     47 /*
     48  * Assign a value to a variable.
     49  */
     50 
     51 assign(name, value)
     52 	char name[], value[];
     53 {
     54 	register struct var *vp;
     55 	register int h;
     56 
     57 	h = hash(name);
     58 	vp = lookup(name);
     59 	if (vp == NOVAR) {
     60 		vp = (struct var *) calloc(sizeof *vp, 1);
     61 		vp->v_name = vcopy(name);
     62 		vp->v_link = variables[h];
     63 		variables[h] = vp;
     64 	}
     65 	else
     66 		vfree(vp->v_value);
     67 	vp->v_value = vcopy(value);
     68 }
     69 
     70 /*
     71  * Free up a variable string.  We do not bother to allocate
     72  * strings whose value is "" since they are expected to be frequent.
     73  * Thus, we cannot free same!
     74  */
     75 
     76 vfree(cp)
     77 	char *cp;
     78 {
     79 	if (*cp)
     80 		free(cp);
     81 }
     82 
     83 /*
     84  * Copy a variable value into permanent (ie, not collected after each
     85  * command) space.  Do not bother to alloc space for ""
     86  */
     87 
     88 char *
     89 vcopy(str)
     90 	char str[];
     91 {
     92 	char *new;
     93 	unsigned len;
     94 
     95 	if (*str == '\0')
     96 		return "";
     97 	len = strlen(str) + 1;
     98 	if ((new = malloc(len)) == NULL)
     99 		panic("Out of memory");
    100 	bcopy(str, new, (int) len);
    101 	return new;
    102 }
    103 
    104 /*
    105  * Get the value of a variable and return it.
    106  * Look in the environment if its not available locally.
    107  */
    108 
    109 char *
    110 value(name)
    111 	char name[];
    112 {
    113 	register struct var *vp;
    114 
    115 	if ((vp = lookup(name)) == NOVAR)
    116 		return(getenv(name));
    117 	return(vp->v_value);
    118 }
    119 
    120 /*
    121  * Locate a variable and return its variable
    122  * node.
    123  */
    124 
    125 struct var *
    126 lookup(name)
    127 	register char name[];
    128 {
    129 	register struct var *vp;
    130 
    131 	for (vp = variables[hash(name)]; vp != NOVAR; vp = vp->v_link)
    132 		if (*vp->v_name == *name && equal(vp->v_name, name))
    133 			return(vp);
    134 	return(NOVAR);
    135 }
    136 
    137 /*
    138  * Locate a group name and return it.
    139  */
    140 
    141 struct grouphead *
    142 findgroup(name)
    143 	register char name[];
    144 {
    145 	register struct grouphead *gh;
    146 
    147 	for (gh = groups[hash(name)]; gh != NOGRP; gh = gh->g_link)
    148 		if (*gh->g_name == *name && equal(gh->g_name, name))
    149 			return(gh);
    150 	return(NOGRP);
    151 }
    152 
    153 /*
    154  * Print a group out on stdout
    155  */
    156 
    157 printgroup(name)
    158 	char name[];
    159 {
    160 	register struct grouphead *gh;
    161 	register struct group *gp;
    162 
    163 	if ((gh = findgroup(name)) == NOGRP) {
    164 		printf("\"%s\": not a group\n", name);
    165 		return;
    166 	}
    167 	printf("%s\t", gh->g_name);
    168 	for (gp = gh->g_list; gp != NOGE; gp = gp->ge_link)
    169 		printf(" %s", gp->ge_name);
    170 	putchar('\n');
    171 }
    172 
    173 /*
    174  * Hash the passed string and return an index into
    175  * the variable or group hash table.
    176  */
    177 
    178 hash(name)
    179 	register char *name;
    180 {
    181 	register h = 0;
    182 
    183 	while (*name) {
    184 		h <<= 2;
    185 		h += *name++;
    186 	}
    187 	if (h < 0 && (h = -h) < 0)
    188 		h = 0;
    189 	return (h % HSHSIZE);
    190 }
    191