usr.bin/mail/vars.c

   1 /*      $NetBSD: vars.c,v 1.17 2006/11/28 18:45:32 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. Neither the name of the University nor the names of its contributors
  16  *    may be used to endorse or promote products derived from this software
  17  *    without specific prior written permission.
  18  *
  19  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  29  * SUCH DAMAGE.
  30  */
  31
  32 #include <sys/cdefs.h>
  33 #ifndef lint
  34 #if 0
  35 static char sccsid[] = "@(#)vars.c      8.1 (Berkeley) 6/6/93";
  36 #else
  37 __RCSID("$NetBSD: vars.c,v 1.17 2006/11/28 18:45:32 christos Exp $");
  38 #endif
  39 #endif /* not lint */
  40
  41 #include "rcv.h"
  42 #include <util.h>
  43
  44 #include "extern.h"
  45
  46 /*
  47  * Mail -- a mail program
  48  *
  49  * Variable handling stuff.
  50  */
  51
  52 /*
  53  * Free up a variable string.  We do not bother to allocate
  54  * strings whose value is "" since they are expected to be frequent.
  55  * Thus, we cannot free same!
  56  */
  57 PUBLIC void
  58 v_free(char *cp)
  59 {
  60         if (*cp)
  61                 free(cp);
  62 }
  63
  64 /*
  65  * Copy a variable value into permanent (ie, not collected after each
  66  * command) space.  Do not bother to alloc space for ""
  67  */
  68 PUBLIC char *
  69 vcopy(const char str[])
  70 {
  71         char *new;
  72         size_t len;
  73
  74         if (*str == '\0')
  75                 return estrdup("");
  76         len = strlen(str) + 1;
  77         new = emalloc(len);
  78         (void)memmove(new, str, len);
  79         return new;
  80 }
  81
  82 /*
  83  * Hash the passed string and return an index into
  84  * the variable or group hash table.
  85  */
  86 PUBLIC int
  87 hash(const char *name)
  88 {
  89         int h = 0;
  90
  91         while (*name) {
  92                 h <<= 2;
  93                 h += *name++;
  94         }
  95         if (h < 0 && (h = -h) < 0)
  96                 h = 0;
  97         return h % HSHSIZE;
  98 }
  99
 100 /*
 101  * Locate a variable and return its variable
 102  * node.
 103  */
 104 PUBLIC struct var *
 105 lookup(const char name[])
 106 {
 107         struct var *vp;
 108
 109         for (vp = variables[hash(name)]; vp != NULL; vp = vp->v_link)
 110                 if (*vp->v_name == *name && equal(vp->v_name, name))
 111                         return vp;
 112         return NULL;
 113 }
 114
 115 /*
 116  * Assign a value to a variable.
 117  */
 118 PUBLIC void
 119 assign(const char name[], const char values[])
 120 {
 121         struct var *vp;
 122         int h;
 123
 124         h = hash(name);
 125         vp = lookup(name);
 126         if (vp == NULL) {
 127                 vp = ecalloc(1, sizeof(*vp));
 128                 vp->v_name = vcopy(name);
 129                 vp->v_link = variables[h];
 130                 variables[h] = vp;
 131         }
 132         else
 133                 v_free(vp->v_value);
 134         vp->v_value = vcopy(values);
 135 }
 136
 137 /*
 138  * Get the value of a variable and return it.
 139  * Look in the environment if its not available locally.
 140  */
 141 PUBLIC char *
 142 value(const char name[])
 143 {
 144         struct var *vp;
 145
 146         if ((vp = lookup(name)) == NULL)
 147                 return getenv(name);
 148         return vp->v_value;
 149 }
 150
 151 /*
 152  * Locate a group name and return it.
 153  */
 154 PUBLIC struct grouphead *
 155 findgroup(const char name[])
 156 {
 157         struct grouphead *gh;
 158
 159         for (gh = groups[hash(name)]; gh != NULL; gh = gh->g_link)
 160                 if (*gh->g_name == *name && equal(gh->g_name, name))
 161                         return gh;
 162         return NULL;
 163 }
 164
 165 /*
 166  * Print a group out on stdout
 167  */
 168 PUBLIC void
 169 printgroup(const char name[])
 170 {
 171         struct grouphead *gh;
 172         struct group *gp;
 173
 174         if ((gh = findgroup(name)) == NULL) {
 175                 (void)printf("\"%s\": not a group\n", name);
 176                 return;
 177         }
 178         (void)printf("%s\t", gh->g_name);
 179         for (gp = gh->g_list; gp != NULL; gp = gp->ge_link)
 180                 (void)printf(" %s", gp->ge_name);
 181         (void)putchar('\n');
 182 }