char *getenv(const char *name) { int offset; char *_findenv(); return _findenv(name, &offset); }
/* * P1003.1-1996 implementation of getenv(). */ char *getenv(const char *name) { int ignore; char *temp; _environ_lock(); temp = _findenv(name, &ignore, 0); _environ_unlock(); return temp; }
/* * setenv -- * Set the value of the environmental variable "name" to be * "value". If rewrite is set, replace any current value. */ int setenv(const char *name, const char *value, int rewrite) { static char **alloced; /* if allocated space before */ register char *c; int l_value, offset; #if defined(MINGW32) if (! environ_c) environ_c = environ; #endif if (*value == '=') /* no `=' in value */ ++value; l_value = strlen(value); if ((c = _findenv(name, &offset))) { /* find if already exists */ if (!rewrite) return (0); if (strlen(c) >= l_value) { /* old larger; copy over */ while ( (*c++ = *value++) ); return (0); } } else { /* create new slot */ register int cnt; register char **p; for (p = *p_environ, cnt = 0; *p; ++p, ++cnt); if (alloced == *p_environ) { /* just increase size */ p = (char **)realloc((char *)(*p_environ), (size_t)(sizeof(char *) * (cnt + 2))); if (!p) return (-1); alloced = *p_environ = p; } else { /* get new space */ /* copy old entries into it */ p = malloc((size_t)(sizeof(char *) * (cnt + 2))); if (!p) return (-1); memcpy(p, *p_environ, cnt * sizeof(char *)); alloced = *p_environ = p; } (*p_environ)[cnt + 1] = NULL; offset = cnt; } for (c = (char *)name; *c && *c != '='; ++c); /* no `=' in name */ if (!((*p_environ)[offset] = /* name + `=' + value */ malloc((size_t)((int)(c - name) + l_value + 2)))) return (-1); for (c = (*p_environ)[offset]; (*c = *name++) && *c != '='; ++c); for (*c++ = '='; (*c++ = *value++); ); return (0); }
/* * unsetenv(name) -- * Delete environmental variable "name". */ void unsetenv(const char *name) { register char **p; int offset; #if defined(MINGW32) if (! environ_c) environ_c = environ; #endif while (_findenv(name, &offset)) /* if set multiple times */ for (p = &(*p_environ)[offset];; ++p) if (!(*p = *(p + 1))) break; }
/* * Based on the BSD4.4 call unsetenv(). */ void _unsetenv(const char *name) { int offset; char **pp; _environ_lock(); // unset environment variable while(_findenv(name, &offset, 0)) { /* if set multiple times */ for(pp = &environ[offset];; ++pp) { if(!(*pp = *(pp + 1))) { break; } } } _environ_unlock(); return; }
/* * getenv -- * Returns ptr to value associated with name, if any, else NULL. */ char *getenv(const char *name) { int offset; return (_findenv(name, &offset)); }