src/port/setenv.c

   1 /*-------------------------------------------------------------------------
   2  *
   3  * setenv.c
   4  *        setenv() emulation for machines without it
   5  *
   6  * Portions Copyright (c) 1996-2021, PostgreSQL Global Development Group
   7  * Portions Copyright (c) 1994, Regents of the University of California
   8  *
   9  *
  10  * IDENTIFICATION
  11  *        src/port/setenv.c
  12  *
  13  *-------------------------------------------------------------------------
  14  */
  15
  16 #include "c.h"
  17
  18
  19 int
  20 setenv(const char *name, const char *value, int overwrite)
  21 {
  22         char       *envstr;
  23
  24         /* Error conditions, per POSIX */
  25         if (name == NULL || name[0] == '\0' || strchr(name, '=') != NULL ||
  26                 value == NULL)
  27         {
  28                 errno = EINVAL;
  29                 return -1;
  30         }
  31
  32         /* No work if variable exists and we're not to replace it */
  33         if (overwrite == 0 && getenv(name) != NULL)
  34                 return 0;
  35
  36         /*
  37          * Add or replace the value using putenv().  This will leak memory if the
  38          * same variable is repeatedly redefined, but there's little we can do
  39          * about that when sitting atop putenv().
  40          */
  41         envstr = (char *) malloc(strlen(name) + strlen(value) + 2);
  42         if (!envstr)                            /* not much we can do if no memory */
  43                 return -1;
  44
  45         sprintf(envstr, "%s=%s", name, value);
  46
  47         return putenv(envstr);
  48 }