vars.c

   1 /*
   2  * Heirloom mailx - a mail user agent derived from Berkeley Mail.
   3  *
   4  * Copyright (c) 2000-2004 Gunnar Ritter, Freiburg i. Br., Germany.
   5  */
   6 /*
   7  * Copyright (c) 1980, 1993
   8  *      The Regents of the University of California.  All rights reserved.
   9  *
  10  * Redistribution and use in source and binary forms, with or without
  11  * modification, are permitted provided that the following conditions
  12  * are met:
  13  * 1. Redistributions of source code must retain the above copyright
  14  *    notice, this list of conditions and the following disclaimer.
  15  * 2. Redistributions in binary form must reproduce the above copyright
  16  *    notice, this list of conditions and the following disclaimer in the
  17  *    documentation and/or other materials provided with the distribution.
  18  * 3. All advertising materials mentioning features or use of this software
  19  *    must display the following acknowledgement:
  20  *      This product includes software developed by the University of
  21  *      California, Berkeley and its contributors.
  22  * 4. Neither the name of the University nor the names of its contributors
  23  *    may be used to endorse or promote products derived from this software
  24  *    without specific prior written permission.
  25  *
  26  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  27  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  28  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  29  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  30  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  31  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  32  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  33  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  34  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  35  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  36  * SUCH DAMAGE.
  37  */
  38
  39 #ifndef lint
  40 #ifdef  DOSCCS
  41 static char sccsid[] = "@(#)vars.c      2.12 (gritter) 10/1/08";
  42 #endif
  43 #endif /* not lint */
  44
  45 #include "rcv.h"
  46 #include "extern.h"
  47
  48 /*
  49  * Mail -- a mail program
  50  *
  51  * Variable handling stuff.
  52  */
  53
  54 static char *canonify(const char *vn);
  55 static void vfree(char *cp);
  56 static struct var *lookup(const char *name);
  57 static void remove_grouplist(struct grouphead *gh);
  58
  59 /*
  60  * If a variable name begins with a lowercase-character and contains at
  61  * least one '@', it is converted to all-lowercase. This is necessary
  62  * for lookups of names based on email addresses.
  63  *
  64  * Following the standard, only the part following the last '@' should
  65  * be lower-cased, but practice has established otherwise here.
  66  */
  67 static char *
  68 canonify(const char *vn)
  69 {
  70         const char      *vp;
  71
  72         if (upperchar(*vn&0377))
  73                 return (char *)vn;
  74         for (vp = vn; *vp && *vp != '@'; vp++);
  75         if (*vp == '@')
  76                 return i_strdup(vn);
  77         return (char *)vn;
  78 }
  79
  80 /*
  81  * Assign a value to a variable.
  82  */
  83 void
  84 assign(const char *name, const char *value)
  85 {
  86         struct var *vp;
  87         int h;
  88
  89         name = canonify(name);
  90         h = hash(name);
  91         vp = lookup(name);
  92         if (vp == NULL) {
  93                 vp = (struct var *)scalloc(1, sizeof *vp);
  94                 vp->v_name = vcopy(name);
  95                 vp->v_link = variables[h];
  96                 variables[h] = vp;
  97         }
  98         else
  99                 vfree(vp->v_value);
 100         vp->v_value = vcopy(value);
 101 }
 102
 103 /*
 104  * Free up a variable string.  We do not bother to allocate
 105  * strings whose value is "" since they are expected to be frequent.
 106  * Thus, we cannot free same!
 107  */
 108 static void
 109 vfree(char *cp)
 110 {
 111         if (*cp)
 112                 free(cp);
 113 }
 114
 115 /*
 116  * Copy a variable value into permanent (ie, not collected after each
 117  * command) space.  Do not bother to alloc space for ""
 118  */
 119
 120 char *
 121 vcopy(const char *str)
 122 {
 123         char *new;
 124         unsigned len;
 125
 126         if (*str == '\0')
 127                 return "";
 128         len = strlen(str) + 1;
 129         new = smalloc(len);
 130         memcpy(new, str, (int) len);
 131         return new;
 132 }
 133
 134 /*
 135  * Get the value of a variable and return it.
 136  * Look in the environment if its not available locally.
 137  */
 138
 139 char *
 140 value(const char *name)
 141 {
 142         struct var *vp;
 143         char    *vs;
 144
 145         name = canonify(name);
 146         if ((vp = lookup(name)) == NULL) {
 147                 if ((vs = getenv(name)) != NULL && *vs)
 148                         vs = savestr(vs);
 149                 return vs;
 150         }
 151         return vp->v_value;
 152 }
 153
 154 /*
 155  * Locate a variable and return its variable
 156  * node.
 157  */
 158
 159 static struct var *
 160 lookup(const char *name)
 161 {
 162         struct var *vp;
 163
 164         for (vp = variables[hash(name)]; vp != NULL; vp = vp->v_link)
 165                 if (*vp->v_name == *name && equal(vp->v_name, name))
 166                         return(vp);
 167         return(NULL);
 168 }
 169
 170 /*
 171  * Locate a group name and return it.
 172  */
 173
 174 struct grouphead *
 175 findgroup(char *name)
 176 {
 177         struct grouphead *gh;
 178
 179         for (gh = groups[hash(name)]; gh != NULL; gh = gh->g_link)
 180                 if (*gh->g_name == *name && equal(gh->g_name, name))
 181                         return(gh);
 182         return(NULL);
 183 }
 184
 185 /*
 186  * Print a group out on stdout
 187  */
 188 void
 189 printgroup(char *name)
 190 {
 191         struct grouphead *gh;
 192         struct group *gp;
 193
 194         if ((gh = findgroup(name)) == NULL) {
 195                 printf(catgets(catd, CATSET, 202, "\"%s\": not a group\n"),
 196                                 name);
 197                 return;
 198         }
 199         printf("%s\t", gh->g_name);
 200         for (gp = gh->g_list; gp != NULL; gp = gp->ge_link)
 201                 printf(" %s", gp->ge_name);
 202         putchar('\n');
 203 }
 204
 205 /*
 206  * Hash the passed string and return an index into
 207  * the variable or group hash table.
 208  */
 209 int
 210 hash(const char *name)
 211 {
 212         int h = 0;
 213
 214         while (*name) {
 215                 h <<= 2;
 216                 h += *name++;
 217         }
 218         if (h < 0 && (h = -h) < 0)
 219                 h = 0;
 220         return (h % HSHSIZE);
 221 }
 222
 223 int
 224 unset_internal(const char *name)
 225 {
 226         struct var *vp, *vp2;
 227         int h;
 228
 229         name = canonify(name);
 230         if ((vp2 = lookup(name)) == NULL) {
 231                 if (!sourcing && !unset_allow_undefined) {
 232                         printf(catgets(catd, CATSET, 203,
 233                                 "\"%s\": undefined variable\n"), name);
 234                         return 1;
 235                 }
 236                 return 0;
 237         }
 238         h = hash(name);
 239         if (vp2 == variables[h]) {
 240                 variables[h] = variables[h]->v_link;
 241                 vfree(vp2->v_name);
 242                 vfree(vp2->v_value);
 243                 free(vp2);
 244                 return 0;
 245         }
 246         for (vp = variables[h]; vp->v_link != vp2; vp = vp->v_link);
 247         vp->v_link = vp2->v_link;
 248         vfree(vp2->v_name);
 249         vfree(vp2->v_value);
 250         free(vp2);
 251         return 0;
 252 }
 253
 254 static void
 255 remove_grouplist(struct grouphead *gh)
 256 {
 257         struct group *gp, *gq;
 258
 259         if ((gp = gh->g_list) != NULL) {
 260                 for (; gp; gp = gq) {
 261                         gq = gp->ge_link;
 262                         vfree(gp->ge_name);
 263                         free(gp);
 264                 }
 265         }
 266 }
 267
 268 void
 269 remove_group(const char *name)
 270 {
 271         struct grouphead *gh, *gp = NULL;
 272         int h = hash(name);
 273
 274         for (gh = groups[h]; gh != NULL; gh = gh->g_link) {
 275                 if (*gh->g_name == *name && equal(gh->g_name, name)) {
 276                         remove_grouplist(gh);
 277                         vfree(gh->g_name);
 278                         if (gp != NULL)
 279                                 gp->g_link = gh->g_link;
 280                         else
 281                                 groups[h] = NULL;
 282                         free(gh);
 283                         break;
 284                 }
 285                 gp = gh;
 286         }
 287 }