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. Neither the name of the University nor the names of its contributors
  14  *    may be used to endorse or promote products derived from this software
  15  *    without specific prior written permission.
  16  *
  17  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  27  * SUCH DAMAGE.
  28  *
  29  * @(#)vars.c   8.1 (Berkeley) 6/6/93
  30  * $FreeBSD: src/usr.bin/mail/vars.c,v 1.1.1.1.14.3 2003/01/06 05:46:04 mikeh Exp $
  31  * $DragonFly: src/usr.bin/mail/vars.c,v 1.4 2004/09/08 03:01:11 joerg Exp $
  32  */
  33
  34 #include "rcv.h"
  35 #include "extern.h"
  36
  37 /*
  38  * Mail -- a mail program
  39  *
  40  * Variable handling stuff.
  41  */
  42
  43 /*
  44  * Assign a value to a variable.
  45  */
  46 void
  47 assign(const char *name, const char *value)
  48 {
  49         struct var *vp;
  50         int h;
  51
  52         h = hash(name);
  53         vp = lookup(name);
  54         if (vp == NULL) {
  55                 vp = calloc(sizeof(*vp), 1);
  56                 vp->v_name = vcopy(name);
  57                 vp->v_link = variables[h];
  58                 variables[h] = vp;
  59         }
  60         else
  61                 vfree(vp->v_value);
  62         vp->v_value = vcopy(value);
  63 }
  64
  65 /*
  66  * Free up a variable string.  We do not bother to allocate
  67  * strings whose value is "" since they are expected to be frequent.
  68  * Thus, we cannot free same!
  69  */
  70 void
  71 vfree(char *cp)
  72 {
  73         if (*cp != '\0')
  74                 free(cp);
  75 }
  76
  77 /*
  78  * Copy a variable value into permanent (ie, not collected after each
  79  * command) space.  Do not bother to alloc space for ""
  80  */
  81
  82 char *
  83 vcopy(const char *str)
  84 {
  85         char *new;
  86         unsigned len;
  87
  88         if (*str == '\0')
  89                 return ("");
  90         len = strlen(str) + 1;
  91         if ((new = malloc(len)) == NULL)
  92                 err(1, "Out of memory");
  93         bcopy(str, new, (int)len);
  94         return (new);
  95 }
  96
  97 /*
  98  * Get the value of a variable and return it.
  99  * Look in the environment if its not available locally.
 100  */
 101
 102 char *
 103 value(const char *name)
 104 {
 105         struct var *vp;
 106
 107         if ((vp = lookup(name)) == NULL)
 108                 return (getenv(name));
 109         return (vp->v_value);
 110 }
 111
 112 /*
 113  * Locate a variable and return its variable
 114  * node.
 115  */
 116
 117 struct var *
 118 lookup(const char *name)
 119 {
 120         struct var *vp;
 121
 122         for (vp = variables[hash(name)]; vp != NULL; vp = vp->v_link)
 123                 if (*vp->v_name == *name && equal(vp->v_name, name))
 124                         return (vp);
 125         return (NULL);
 126 }
 127
 128 /*
 129  * Locate a group name and return it.
 130  */
 131
 132 struct grouphead *
 133 findgroup(char *name)
 134 {
 135         struct grouphead *gh;
 136
 137         for (gh = groups[hash(name)]; gh != NULL; gh = gh->g_link)
 138                 if (*gh->g_name == *name && equal(gh->g_name, name))
 139                         return (gh);
 140         return (NULL);
 141 }
 142
 143 /*
 144  * Print a group out on stdout
 145  */
 146 void
 147 printgroup(char *name)
 148 {
 149         struct grouphead *gh;
 150         struct group *gp;
 151
 152         if ((gh = findgroup(name)) == NULL) {
 153                 printf("\"%s\": not a group\n", name);
 154                 return;
 155         }
 156         printf("%s\t", gh->g_name);
 157         for (gp = gh->g_list; gp != NULL; gp = gp->ge_link)
 158                 printf(" %s", gp->ge_name);
 159         printf("\n");
 160 }
 161
 162 /*
 163  * Hash the passed string and return an index into
 164  * the variable or group hash table.
 165  */
 166 int
 167 hash(const char *name)
 168 {
 169         int h = 0;
 170
 171         while (*name != '\0') {
 172                 h <<= 2;
 173                 h += *name++;
 174         }
 175         if (h < 0 && (h = -h) < 0)
 176                 h = 0;
 177         return (h % HSHSIZE);
 178 }