lib/roken/environment.c

   1 /*
   2  * Copyright (c) 2000, 2005 Kungliga Tekniska Högskolan
   3  * (Royal Institute of Technology, Stockholm, Sweden).
   4  * All rights reserved.
   5  *
   6  * Redistribution and use in source and binary forms, with or without
   7  * modification, are permitted provided that the following conditions
   8  * are met:
   9  *
  10  * 1. Redistributions of source code must retain the above copyright
  11  *    notice, this list of conditions and the following disclaimer.
  12  *
  13  * 2. Redistributions in binary form must reproduce the above copyright
  14  *    notice, this list of conditions and the following disclaimer in the
  15  *    documentation and/or other materials provided with the distribution.
  16  *
  17  * 3. Neither the name of the Institute nor the names of its contributors
  18  *    may be used to endorse or promote products derived from this software
  19  *    without specific prior written permission.
  20  *
  21  * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
  22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
  25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  31  * SUCH DAMAGE.
  32  */
  33
  34
  35 #ifdef HAVE_CONFIG_H
  36 #include <config.h>
  37 RCSID("$Id$");
  38 #endif
  39
  40 #include <stdio.h>
  41 #include <string.h>
  42 #include <ctype.h>
  43 #include "roken.h"
  44
  45 /* find assignment in env list; len is length of variable including
  46  * equal
  47  */
  48
  49 static int
  50 find_var(char **env, char *assignment, size_t len)
  51 {
  52     int i;
  53     for(i = 0; env != NULL && env[i] != NULL; i++)
  54         if(strncmp(env[i], assignment, len) == 0)
  55             return i;
  56     return -1;
  57 }
  58
  59 /*
  60  * return count of environment assignments from open file F in
  61  * assigned and list of malloced strings in env, return 0 or errno
  62  * number
  63  */
  64
  65 static int
  66 rk_read_env_file(FILE *F, char ***env, int *assigned)
  67 {
  68     int idx = 0;
  69     int i;
  70     char **l;
  71     char buf[BUFSIZ], *p, *r;
  72     char **tmp;
  73     int ret = 0;
  74
  75     *assigned = 0;
  76
  77     for(idx = 0; *env != NULL && (*env)[idx] != NULL; idx++);
  78     l = *env;
  79
  80     /* This is somewhat more relaxed on what it accepts then
  81      * Wietses sysv_environ from K4 was...
  82      */
  83     while (fgets(buf, BUFSIZ, F) != NULL) {
  84         buf[strcspn(buf, "#\n")] = '\0';
  85
  86         for(p = buf; isspace((unsigned char)*p); p++);
  87         if (*p == '\0')
  88             continue;
  89
  90         /* Here one should check that it's a 'valid' env string... */
  91         r = strchr(p, '=');
  92         if (r == NULL)
  93             continue;
  94
  95         if((i = find_var(l, p, r - p + 1)) >= 0) {
  96             char *val = strdup(p);
  97             if(val == NULL) {
  98                 ret = ENOMEM;
  99                 break;
 100             }
 101             free(l[i]);
 102             l[i] = val;
 103             (*assigned)++;
 104             continue;
 105         }
 106
 107         tmp = realloc(l, (idx+2) * sizeof (char *));
 108         if(tmp == NULL) {
 109             ret = ENOMEM;
 110             break;
 111         }
 112
 113         l = tmp;
 114         l[idx] = strdup(p);
 115         if(l[idx] == NULL) {
 116             ret = ENOMEM;
 117             break;
 118         }
 119         l[++idx] = NULL;
 120         (*assigned)++;
 121     }
 122     if(ferror(F))
 123         ret = errno;
 124     *env = l;
 125     return ret;
 126 }
 127
 128 /*
 129  * return count of environment assignments from file and
 130  * list of malloced strings in `env'
 131  */
 132
 133 int ROKEN_LIB_FUNCTION
 134 read_environment(const char *file, char ***env)
 135 {
 136     int assigned;
 137     FILE *F;
 138
 139     if ((F = fopen(file, "r")) == NULL)
 140         return 0;
 141
 142     rk_read_env_file(F, env, &assigned);
 143     fclose(F);
 144     return assigned;
 145 }
 146
 147 void ROKEN_LIB_FUNCTION
 148 free_environment(char **env)
 149 {
 150     int i;
 151     if (env == NULL)
 152         return;
 153     for (i = 0; env[i]; i++)
 154         free(env[i]);
 155     free(env);
 156 }