usr.bin/mail/vars.c

   1 /*
   2  * Copyright (c) 1980, 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  * @(#)vars.c   8.1 (Berkeley) 6/6/93
  34  * $FreeBSD: src/usr.bin/mail/vars.c,v 1.1.1.1.14.3 2003/01/06 05:46:04 mikeh Exp $
  35  * $DragonFly: src/usr.bin/mail/vars.c,v 1.4 2004/09/08 03:01:11 joerg Exp $
  36  */
  37
  38 #include "rcv.h"
  39 #include "extern.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 void
  51 assign(const char *name, const char *value)
  52 {
  53         struct var *vp;
  54         int h;
  55
  56         h = hash(name);
  57         vp = lookup(name);
  58         if (vp == NULL) {
  59                 vp = calloc(sizeof(*vp), 1);
  60                 vp->v_name = vcopy(name);
  61                 vp->v_link = variables[h];
  62                 variables[h] = vp;
  63         }
  64         else
  65                 vfree(vp->v_value);
  66         vp->v_value = vcopy(value);
  67 }
  68
  69 /*
  70  * Free up a variable string.  We do not bother to allocate
  71  * strings whose value is "" since they are expected to be frequent.
  72  * Thus, we cannot free same!
  73  */
  74 void
  75 vfree(char *cp)
  76 {
  77         if (*cp != '\0')
  78                 free(cp);
  79 }
  80
  81 /*
  82  * Copy a variable value into permanent (ie, not collected after each
  83  * command) space.  Do not bother to alloc space for ""
  84  */
  85
  86 char *
  87 vcopy(const char *str)
  88 {
  89         char *new;
  90         unsigned len;
  91
  92         if (*str == '\0')
  93                 return ("");
  94         len = strlen(str) + 1;
  95         if ((new = malloc(len)) == NULL)
  96                 err(1, "Out of memory");
  97         bcopy(str, new, (int)len);
  98         return (new);
  99 }
 100
 101 /*
 102  * Get the value of a variable and return it.
 103  * Look in the environment if its not available locally.
 104  */
 105
 106 char *
 107 value(const char *name)
 108 {
 109         struct var *vp;
 110
 111         if ((vp = lookup(name)) == NULL)
 112                 return (getenv(name));
 113         return (vp->v_value);
 114 }
 115
 116 /*
 117  * Locate a variable and return its variable
 118  * node.
 119  */
 120
 121 struct var *
 122 lookup(const char *name)
 123 {
 124         struct var *vp;
 125
 126         for (vp = variables[hash(name)]; vp != NULL; vp = vp->v_link)
 127                 if (*vp->v_name == *name && equal(vp->v_name, name))
 128                         return (vp);
 129         return (NULL);
 130 }
 131
 132 /*
 133  * Locate a group name and return it.
 134  */
 135
 136 struct grouphead *
 137 findgroup(char *name)
 138 {
 139         struct grouphead *gh;
 140
 141         for (gh = groups[hash(name)]; gh != NULL; gh = gh->g_link)
 142                 if (*gh->g_name == *name && equal(gh->g_name, name))
 143                         return (gh);
 144         return (NULL);
 145 }
 146
 147 /*
 148  * Print a group out on stdout
 149  */
 150 void
 151 printgroup(char *name)
 152 {
 153         struct grouphead *gh;
 154         struct group *gp;
 155
 156         if ((gh = findgroup(name)) == NULL) {
 157                 printf("\"%s\": not a group\n", name);
 158                 return;
 159         }
 160         printf("%s\t", gh->g_name);
 161         for (gp = gh->g_list; gp != NULL; gp = gp->ge_link)
 162                 printf(" %s", gp->ge_name);
 163         printf("\n");
 164 }
 165
 166 /*
 167  * Hash the passed string and return an index into
 168  * the variable or group hash table.
 169  */
 170 int
 171 hash(const char *name)
 172 {
 173         int h = 0;
 174
 175         while (*name != '\0') {
 176                 h <<= 2;
 177                 h += *name++;
 178         }
 179         if (h < 0 && (h = -h) < 0)
 180                 h = 0;
 181         return (h % HSHSIZE);
 182 }