environ.c

   1 /* $OpenBSD$ */
   2
   3 /*
   4  * Copyright (c) 2009 Nicholas Marriott <nicm@users.sourceforge.net>
   5  *
   6  * Permission to use, copy, modify, and distribute this software for any
   7  * purpose with or without fee is hereby granted, provided that the above
   8  * copyright notice and this permission notice appear in all copies.
   9  *
  10  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
  11  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
  12  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
  13  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
  14  * WHATSOEVER RESULTING FROM LOSS OF MIND, USE, DATA OR PROFITS, WHETHER
  15  * IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING
  16  * OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  17  */
  18
  19 #include <sys/types.h>
  20
  21 #include <stdlib.h>
  22 #include <string.h>
  23
  24 #include "tmux.h"
  25
  26 /*
  27  * Environment - manipulate a set of environment variables.
  28  */
  29
  30 RB_GENERATE(environ, environ_entry, entry, environ_cmp);
  31
  32 int
  33 environ_cmp(struct environ_entry *envent1, struct environ_entry *envent2)
  34 {
  35         return (strcmp(envent1->name, envent2->name));
  36 }
  37
  38 /* Initialise the environment. */
  39 void
  40 environ_init(struct environ *env)
  41 {
  42         RB_INIT(env);
  43 }
  44
  45 /* Free an environment. */
  46 void
  47 environ_free(struct environ *env)
  48 {
  49         struct environ_entry    *envent;
  50
  51         while (!RB_EMPTY(env)) {
  52                 envent = RB_ROOT(env);
  53                 RB_REMOVE(environ, env, envent);
  54                 xfree(envent->name);
  55                 if (envent->value != NULL)
  56                         xfree(envent->value);
  57                 xfree(envent);
  58         }
  59 }
  60
  61 /* Copy one environment into another. */
  62 void
  63 environ_copy(struct environ *srcenv, struct environ *dstenv)
  64 {
  65         struct environ_entry    *envent;
  66
  67         RB_FOREACH(envent, environ, srcenv)
  68                 environ_set(dstenv, envent->name, envent->value);
  69 }
  70
  71 /* Find an environment variable. */
  72 struct environ_entry *
  73 environ_find(struct environ *env, const char *name)
  74 {
  75         struct environ_entry    envent;
  76
  77         envent.name = (char *) name;
  78         return (RB_FIND(environ, env, &envent));
  79 }
  80
  81 /* Set an environment variable. */
  82 void
  83 environ_set(struct environ *env, const char *name, const char *value)
  84 {
  85         struct environ_entry    *envent;
  86
  87         if ((envent = environ_find(env, name)) != NULL) {
  88                 if (envent->value != NULL)
  89                         xfree(envent->value);
  90                 if (value != NULL)
  91                         envent->value = xstrdup(value);
  92                 else
  93                         envent->value = NULL;
  94         } else {
  95                 envent = xmalloc(sizeof *envent);
  96                 envent->name = xstrdup(name);
  97                 if (value != NULL)
  98                         envent->value = xstrdup(value);
  99                 else
 100                         envent->value = NULL;
 101                 RB_INSERT(environ, env, envent);
 102         }
 103 }
 104
 105 /* Set an environment variable from a NAME=VALUE string. */
 106 void
 107 environ_put(struct environ *env, const char *var)
 108 {
 109         char    *name, *value;
 110
 111         value = strchr(var, '=');
 112         if (value == NULL)
 113                 return;
 114         value++;
 115
 116         name = xstrdup(var);
 117         name[strcspn(name, "=")] = '\0';
 118
 119         environ_set(env, name, value);
 120         xfree(name);
 121 }
 122
 123 /* Unset an environment variable. */
 124 void
 125 environ_unset(struct environ *env, const char *name)
 126 {
 127         struct environ_entry    *envent;
 128
 129         if ((envent = environ_find(env, name)) == NULL)
 130                 return;
 131         RB_REMOVE(environ, env, envent);
 132         xfree(envent->name);
 133         if (envent->value != NULL)
 134                 xfree(envent->value);
 135         xfree(envent);
 136 }
 137
 138 /*
 139  * Copy a space-separated list of variables from a destination into a source
 140  * environment.
 141  */
 142 void
 143 environ_update(const char *vars, struct environ *srcenv, struct environ *dstenv)
 144 {
 145         struct environ_entry    *envent;
 146         char                    *copyvars, *var, *next;
 147
 148         copyvars = next = xstrdup(vars);
 149         while ((var = strsep(&next, " ")) != NULL) {
 150                 if ((envent = environ_find(srcenv, var)) == NULL)
 151                         environ_set(dstenv, var, NULL);
 152                 else
 153                         environ_set(dstenv, envent->name, envent->value);
 154         }
 155         xfree(copyvars);
 156 }
 157
 158 /* Push environment into the real environment - use after fork(). */
 159 void
 160 environ_push(struct environ *env)
 161 {
 162         ARRAY_DECL(, char *)    varlist;
 163         struct environ_entry   *envent;
 164         char                  **varp, *var;
 165         u_int                   i;
 166
 167         ARRAY_INIT(&varlist);
 168         for (varp = environ; *varp != NULL; varp++) {
 169                 var = xstrdup(*varp);
 170                 var[strcspn(var, "=")] = '\0';
 171                 ARRAY_ADD(&varlist, var);
 172         }
 173         for (i = 0; i < ARRAY_LENGTH(&varlist); i++)
 174                 unsetenv(ARRAY_ITEM(&varlist, i));
 175         ARRAY_FREE(&varlist);
 176
 177         RB_FOREACH(envent, environ, env) {
 178                 if (envent->value != NULL)
 179                         setenv(envent->name, envent->value, 1);
 180         }
 181 }