/* $Id: setenv.c 5713 2002-09-01 03:04:10Z rra $ ** ** Replacement for a missing setenv. ** ** Written by Russ Allbery ** This work is hereby placed in the public domain by its author. ** ** Provides the same functionality as the standard library routine setenv ** for those platforms that don't have it. */ #include "config.h" #include "clibrary.h" /* If we're running the test suite, rename setenv to avoid conflicts with the system version. */ #if TESTING # define setenv test_setenv int test_setenv(const char *, const char *, int); #endif int setenv(const char *name, const char *value, int overwrite) { char *envstring; if (!overwrite && getenv(name) != NULL) return 0; /* Allocate memory for the environment string. We intentionally don't use concat here, or the xmalloc family of allocation routines, since the intention is to provide a replacement for the standard library function which sets errno and returns in the event of a memory allocation failure. */ envstring = malloc(strlen(name) + 1 + strlen(value) + 1); if (envstring == NULL) return -1; /* Build the environment string and add it to the environment using putenv. Systems without putenv lose, but XPG4 requires it. */ strcpy(envstring, name); strcat(envstring, "="); strcat(envstring, value); return putenv(envstring); /* Note that the memory allocated is not freed. This is intentional; many implementations of putenv assume that the string passed to putenv will never be freed and don't make a copy of it. Repeated use of this function will therefore leak memory, since most implementations of putenv also don't free strings removed from the environment (due to being overwritten). */ }