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 #include <config.h>
  36
  37 #include <stdio.h>
  38 #include <string.h>
  39 #include <ctype.h>
  40 #include "roken.h"
  41
  42 /* find assignment in env list; len is length of variable including
  43  * equal
  44  */
  45
  46 static int
  47 find_var(char **env, char *assignment, size_t len)
  48 {
  49     int i;
  50     for(i = 0; env != NULL && env[i] != NULL; i++)
  51         if(strncmp(env[i], assignment, len) == 0)
  52             return i;
  53     return -1;
  54 }
  55
  56 /*
  57  * return count of environment assignments from open file F in
  58  * assigned and list of malloced strings in env, return 0 or errno
  59  * number
  60  */
  61
  62 static int
  63 read_env_file(FILE *F, char ***env, int *assigned)
  64 {
  65     int idx = 0;
  66     int i;
  67     char **l;
  68     char buf[BUFSIZ], *p, *r;
  69     char **tmp;
  70     int ret = 0;
  71
  72     *assigned = 0;
  73
  74     for(idx = 0; *env != NULL && (*env)[idx] != NULL; idx++);
  75     l = *env;
  76
  77     /* This is somewhat more relaxed on what it accepts then
  78      * Wietses sysv_environ from K4 was...
  79      */
  80     while (fgets(buf, BUFSIZ, F) != NULL) {
  81         buf[strcspn(buf, "#\n")] = '\0';
  82
  83         for(p = buf; isspace((unsigned char)*p); p++);
  84         if (*p == '\0')
  85             continue;
  86
  87         /* Here one should check that it's a 'valid' env string... */
  88         r = strchr(p, '=');
  89         if (r == NULL)
  90             continue;
  91
  92         if((i = find_var(l, p, r - p + 1)) >= 0) {
  93             char *val = strdup(p);
  94             if(val == NULL) {
  95                 ret = ENOMEM;
  96                 break;
  97             }
  98             free(l[i]);
  99             l[i] = val;
 100             (*assigned)++;
 101             continue;
 102         }
 103
 104         tmp = realloc(l, (idx+2) * sizeof (char *));
 105         if(tmp == NULL) {
 106             ret = ENOMEM;
 107             break;
 108         }
 109
 110         l = tmp;
 111         l[idx] = strdup(p);
 112         if(l[idx] == NULL) {
 113             ret = ENOMEM;
 114             break;
 115         }
 116         l[++idx] = NULL;
 117         (*assigned)++;
 118     }
 119     if(ferror(F))
 120         ret = errno;
 121     *env = l;
 122     return ret;
 123 }
 124
 125 /*
 126  * return count of environment assignments from file and
 127  * list of malloced strings in `env'
 128  */
 129
 130 ROKEN_LIB_FUNCTION int ROKEN_LIB_CALL
 131 read_environment(const char *file, char ***env)
 132 {
 133     int assigned;
 134     FILE *F;
 135
 136     if ((F = fopen(file, "r")) == NULL)
 137         return 0;
 138
 139     read_env_file(F, env, &assigned);
 140     fclose(F);
 141     return assigned;
 142 }
 143
 144 ROKEN_LIB_FUNCTION void ROKEN_LIB_CALL
 145 free_environment(char **env)
 146 {
 147     int i;
 148     if (env == NULL)
 149         return;
 150     for (i = 0; env[i]; i++)
 151         free(env[i]);
 152     free(env);
 153 }