vars.c

   1 /*
   2  * S-nail - a mail user agent derived from Berkeley Mail.
   3  *
   4  * Copyright (c) 2000-2004 Gunnar Ritter, Freiburg i. Br., Germany.
   5  * Copyright (c) 2012 Steffen "Daode" Nurpmeso.
   6  */
   7 /*
   8  * Copyright (c) 1980, 1993
   9  *      The Regents of the University of California.  All rights reserved.
  10  *
  11  * Redistribution and use in source and binary forms, with or without
  12  * modification, are permitted provided that the following conditions
  13  * are met:
  14  * 1. Redistributions of source code must retain the above copyright
  15  *    notice, this list of conditions and the following disclaimer.
  16  * 2. Redistributions in binary form must reproduce the above copyright
  17  *    notice, this list of conditions and the following disclaimer in the
  18  *    documentation and/or other materials provided with the distribution.
  19  * 3. All advertising materials mentioning features or use of this software
  20  *    must display the following acknowledgement:
  21  *      This product includes software developed by the University of
  22  *      California, Berkeley and its contributors.
  23  * 4. Neither the name of the University nor the names of its contributors
  24  *    may be used to endorse or promote products derived from this software
  25  *    without specific prior written permission.
  26  *
  27  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  28  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  29  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  30  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  31  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  32  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  33  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  34  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  35  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  36  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  37  * SUCH DAMAGE.
  38  */
  39
  40 #include "rcv.h"
  41 #include "extern.h"
  42
  43 /*
  44  * Mail -- a mail program
  45  *
  46  * Variable handling stuff.
  47  */
  48
  49 static char *canonify(const char *vn);
  50 static void vfree(char *cp);
  51 static struct var *lookup(const char *name);
  52 static void remove_grouplist(struct grouphead *gh);
  53
  54 /*
  55  * If a variable name begins with a lowercase-character and contains at
  56  * least one '@', it is converted to all-lowercase. This is necessary
  57  * for lookups of names based on email addresses.
  58  *
  59  * Following the standard, only the part following the last '@' should
  60  * be lower-cased, but practice has established otherwise here.
  61  */
  62 static char *
  63 canonify(const char *vn)
  64 {
  65         const char      *vp;
  66
  67         if (upperchar(*vn&0377))
  68                 return (char *)vn;
  69         for (vp = vn; *vp && *vp != '@'; vp++);
  70         if (*vp == '@')
  71                 return i_strdup(vn);
  72         return (char *)vn;
  73 }
  74
  75 /*
  76  * Assign a value to a variable.
  77  */
  78 void
  79 assign(const char *name, const char *value)
  80 {
  81         struct var *vp;
  82         int h;
  83
  84         name = canonify(name);
  85         h = hash(name);
  86         vp = lookup(name);
  87         if (vp == NULL) {
  88                 vp = (struct var *)scalloc(1, sizeof *vp);
  89                 vp->v_name = vcopy(name);
  90                 vp->v_link = variables[h];
  91                 variables[h] = vp;
  92         }
  93         else
  94                 vfree(vp->v_value);
  95         vp->v_value = vcopy(value);
  96 }
  97
  98 /*
  99  * Free up a variable string.  We do not bother to allocate
 100  * strings whose value is "" since they are expected to be frequent.
 101  * Thus, we cannot free same!
 102  */
 103 static void
 104 vfree(char *cp)
 105 {
 106         if (*cp)
 107                 free(cp);
 108 }
 109
 110 /*
 111  * Copy a variable value into permanent (ie, not collected after each
 112  * command) space.  Do not bother to alloc space for ""
 113  */
 114
 115 char *
 116 vcopy(const char *str)
 117 {
 118         char *new;
 119         unsigned len;
 120
 121         if (*str == '\0')
 122                 return "";
 123         len = strlen(str) + 1;
 124         new = smalloc(len);
 125         memcpy(new, str, (int) len);
 126         return new;
 127 }
 128
 129 /*
 130  * Get the value of a variable and return it.
 131  * Look in the environment if its not available locally.
 132  */
 133
 134 char *
 135 value(const char *name)
 136 {
 137         struct var *vp;
 138         char    *vs;
 139
 140         name = canonify(name);
 141         if ((vp = lookup(name)) == NULL) {
 142                 if ((vs = getenv(name)) != NULL && *vs)
 143                         vs = savestr(vs);
 144                 return vs;
 145         }
 146         return vp->v_value;
 147 }
 148
 149 /*
 150  * Locate a variable and return its variable
 151  * node.
 152  */
 153
 154 static struct var *
 155 lookup(const char *name)
 156 {
 157         struct var *vp;
 158
 159         for (vp = variables[hash(name)]; vp != NULL; vp = vp->v_link)
 160                 if (*vp->v_name == *name && strcmp(vp->v_name, name) == 0)
 161                         return(vp);
 162         return(NULL);
 163 }
 164
 165 /*
 166  * Locate a group name and return it.
 167  */
 168
 169 struct grouphead *
 170 findgroup(char *name)
 171 {
 172         struct grouphead *gh;
 173
 174         for (gh = groups[hash(name)]; gh != NULL; gh = gh->g_link)
 175                 if (*gh->g_name == *name && strcmp(gh->g_name, name) == 0)
 176                         return(gh);
 177         return(NULL);
 178 }
 179
 180 /*
 181  * Print a group out on stdout
 182  */
 183 void
 184 printgroup(char *name)
 185 {
 186         struct grouphead *gh;
 187         struct group *gp;
 188
 189         if ((gh = findgroup(name)) == NULL) {
 190                 printf(catgets(catd, CATSET, 202, "\"%s\": not a group\n"),
 191                                 name);
 192                 return;
 193         }
 194         printf("%s\t", gh->g_name);
 195         for (gp = gh->g_list; gp != NULL; gp = gp->ge_link)
 196                 printf(" %s", gp->ge_name);
 197         putchar('\n');
 198 }
 199
 200 /*
 201  * Hash the passed string and return an index into
 202  * the variable or group hash table.
 203  */
 204 int
 205 hash(const char *name)
 206 {
 207         int h = 0;
 208
 209         while (*name) {
 210                 h <<= 2;
 211                 h += *name++;
 212         }
 213         if (h < 0 && (h = -h) < 0)
 214                 h = 0;
 215         return (h % HSHSIZE);
 216 }
 217
 218 int
 219 unset_internal(const char *name)
 220 {
 221         struct var *vp, *vp2;
 222         int h;
 223
 224         name = canonify(name);
 225         if ((vp2 = lookup(name)) == NULL) {
 226                 if (!sourcing && !unset_allow_undefined) {
 227                         printf(catgets(catd, CATSET, 203,
 228                                 "\"%s\": undefined variable\n"), name);
 229                         return 1;
 230                 }
 231                 return 0;
 232         }
 233         h = hash(name);
 234         if (vp2 == variables[h]) {
 235                 variables[h] = variables[h]->v_link;
 236                 vfree(vp2->v_name);
 237                 vfree(vp2->v_value);
 238                 free(vp2);
 239                 return 0;
 240         }
 241         for (vp = variables[h]; vp->v_link != vp2; vp = vp->v_link);
 242         vp->v_link = vp2->v_link;
 243         vfree(vp2->v_name);
 244         vfree(vp2->v_value);
 245         free(vp2);
 246         return 0;
 247 }
 248
 249 static void
 250 remove_grouplist(struct grouphead *gh)
 251 {
 252         struct group *gp, *gq;
 253
 254         if ((gp = gh->g_list) != NULL) {
 255                 for (; gp; gp = gq) {
 256                         gq = gp->ge_link;
 257                         vfree(gp->ge_name);
 258                         free(gp);
 259                 }
 260         }
 261 }
 262
 263 void
 264 remove_group(const char *name)
 265 {
 266         struct grouphead *gh, *gp = NULL;
 267         int h = hash(name);
 268
 269         for (gh = groups[h]; gh != NULL; gh = gh->g_link) {
 270                 if (*gh->g_name == *name && strcmp(gh->g_name, name) == 0) {
 271                         remove_grouplist(gh);
 272                         vfree(gh->g_name);
 273                         if (gp != NULL)
 274                                 gp->g_link = gh->g_link;
 275                         else
 276                                 groups[h] = NULL;
 277                         free(gh);
 278                         break;
 279                 }
 280                 gp = gh;
 281         }
 282 }