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, int h);
  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))
  68                 return ((char*)vn);
  69         for (vp = vn; *vp && *vp != '@'; vp++)
  70                 ;
  71         return ((*vp == '@') ? i_strdup(vn) : (char*)vn);
  72 }
  73
  74 /*
  75  * Assign a value to a variable.
  76  */
  77 void
  78 assign(const char *name, const char *value)
  79 {
  80         struct var *vp;
  81         int h;
  82
  83         name = canonify(name);
  84         h = hash(name);
  85
  86         vp = lookup(name, h);
  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 *news;
 119         unsigned len;
 120
 121         if (*str == '\0')
 122                 return "";
 123         len = strlen(str) + 1;
 124         news = smalloc(len);
 125         memcpy(news, str, (int)len);
 126         return (news);
 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, -1)) == 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 node.
 151  */
 152 static struct var *
 153 lookup(const char *name, int h)
 154 {
 155         struct var **vap, *lvp, *vp;
 156
 157         vap = variables + ((h >= 0) ? h : hash(name));
 158
 159         for (lvp = NULL, vp = *vap; vp != NULL; lvp = vp, vp = vp->v_link)
 160                 if (*vp->v_name == *name && strcmp(vp->v_name, name) == 0) {
 161                         /* Relink as head, hope it "sorts on usage" over time */
 162                         if (lvp != NULL) {
 163                                 lvp->v_link = vp->v_link;
 164                                 vp->v_link = *vap;
 165                                 *vap = vp;
 166                         }
 167                         return (vp);
 168                 }
 169         return (NULL);
 170 }
 171
 172 /*
 173  * Locate a group name and return it.
 174  */
 175
 176 struct grouphead *
 177 findgroup(char *name)
 178 {
 179         struct grouphead *gh;
 180
 181         for (gh = groups[hash(name)]; gh != NULL; gh = gh->g_link)
 182                 if (*gh->g_name == *name && strcmp(gh->g_name, name) == 0)
 183                         return(gh);
 184         return(NULL);
 185 }
 186
 187 /*
 188  * Print a group out on stdout
 189  */
 190 void
 191 printgroup(char *name)
 192 {
 193         struct grouphead *gh;
 194         struct group *gp;
 195
 196         if ((gh = findgroup(name)) == NULL) {
 197                 printf(catgets(catd, CATSET, 202, "\"%s\": not a group\n"),
 198                                 name);
 199                 return;
 200         }
 201         printf("%s\t", gh->g_name);
 202         for (gp = gh->g_list; gp != NULL; gp = gp->ge_link)
 203                 printf(" %s", gp->ge_name);
 204         putchar('\n');
 205 }
 206
 207 /*
 208  * Hash the passed string and return an index into
 209  * the variable or group hash table.
 210  * Use Chris Torek's hash algorithm.
 211  */
 212 int
 213 hash(const char *name)
 214 {
 215         int h = 0;
 216
 217         while (*name) {
 218                 h *= 33;
 219                 h += *name++;
 220         }
 221         if (h < 0 && (h = -h) < 0)
 222                 h = 0;
 223         return (h % HSHSIZE);
 224 }
 225
 226 int
 227 unset_internal(const char *name)
 228 {
 229         int h;
 230         struct var *vp;
 231
 232         name = canonify(name);
 233         h = hash(name);
 234
 235         if ((vp = lookup(name, h)) == NULL) {
 236                 if (! sourcing && ! unset_allow_undefined) {
 237                         printf(tr(203, "\"%s\": undefined variable\n"), name);
 238                         return (1);
 239                 }
 240                 return (0);
 241         }
 242
 243         /* Always listhead after lookup() */
 244         variables[h] = variables[h]->v_link;
 245         vfree(vp->v_name);
 246         vfree(vp->v_value);
 247         free(vp);
 248         return (0);
 249 }
 250
 251 static void
 252 remove_grouplist(struct grouphead *gh)
 253 {
 254         struct group *gp, *gq;
 255
 256         if ((gp = gh->g_list) != NULL) {
 257                 for (; gp; gp = gq) {
 258                         gq = gp->ge_link;
 259                         vfree(gp->ge_name);
 260                         free(gp);
 261                 }
 262         }
 263 }
 264
 265 void
 266 remove_group(const char *name)
 267 {
 268         struct grouphead *gh, *gp = NULL;
 269         int h = hash(name);
 270
 271         for (gh = groups[h]; gh != NULL; gh = gh->g_link) {
 272                 if (*gh->g_name == *name && strcmp(gh->g_name, name) == 0) {
 273                         remove_grouplist(gh);
 274                         vfree(gh->g_name);
 275                         if (gp != NULL)
 276                                 gp->g_link = gh->g_link;
 277                         else
 278                                 groups[h] = NULL;
 279                         free(gh);
 280                         break;
 281                 }
 282                 gp = gh;
 283         }
 284 }