_putenv SetEnv

int SetEnv ( const wchar_t *  option ) Internal version of _wputenv and _putenv. It works duplicates the original envirnments created during initilization if needed to prevent having spurious pointers floating around. Then it updates the internal environment tables (_environ and _wenviron) and at last updates the OS environemnt. Note that there can happen situation when the internal [_w]environ arrays will be updated, but the OS environment update will fail. In this case we don't undo the changes to the [_w]environ tables to comply with the Microsoft behaviour (and it's also much easier :-). Definition at line 210 of file environ.c. { wchar_t *epos, *name; wchar_t **wenvptr; wchar_t *woption; char *mboption; int remove, index, count, size, result = 0, found = 0; if (option == NULL || (epos = wcschr(option, L'=')) == NULL) return -1; remove = (epos[1] == 0); /* Duplicate environment if needed. */ if (_environ == __initenv) { if ((_environ = DuplicateEnvironment(_environ, 0)) == __initenv) return -1; } if (_wenviron == __winitenv) { if ((_wenviron = (wchar_t**)DuplicateEnvironment((char**)_wenviron, 1)) == __winitenv) return -1; } /* Create a copy of the option name. */ name = malloc((epos - option + 1) * sizeof(wchar_t)); if (name == NULL) return -1; memcpy(name, option, (epos - option) * sizeof(wchar_t)); name[epos - option] = 0; /* Find the option we're trying to modify. */ for (index = 0, wenvptr = _wenviron; *wenvptr != NULL; wenvptr++, index++) { if (!_wcsnicmp(*wenvptr, option, epos - option)) { found = 1; break; } } if (remove) { if (!found) { free(name); return 0; } /* Remove the option from wide character environment. */ free(*wenvptr); for (count = index; *wenvptr != NULL; wenvptr++, count++) *wenvptr = *(wenvptr + 1); _wenviron = realloc(_wenviron, count * sizeof(wchar_t*)); /* Remove the option from multibyte environment. We assume * the environments are in sync and the option is at the * same position. */ free(_environ[index]); memmove(&_environ[index], &_environ[index+1], (count - index) * sizeof(char*)); _environ = realloc(_environ, count * sizeof(char*)); result = SetEnvironmentVariableW(name, NULL) ? 0 : -1; } else { /* Make a copy of the option that we will store in the environment block. */ woption = _wcsdup((wchar_t*)option); if (woption == NULL) { free(name); return -1; } /* Create a multibyte copy of the option. */ size = WideCharToMultiByte(CP_ACP, 0, option, -1, NULL, 0, NULL, NULL); mboption = malloc(size); if (mboption == NULL) { free(name); free(woption); return -1; } WideCharToMultiByte(CP_ACP, 0, option, -1, mboption, size, NULL, NULL); if (found) { /* Replace the current entry. */ free(*wenvptr); *wenvptr = woption; free(_environ[index]); _environ[index] = mboption; } else { wchar_t **wnewenv; char **mbnewenv; /* Get the size of the original environment. */ for (count = index; *wenvptr != NULL; wenvptr++, count++) ; /* Create a new entry. */ if ((wnewenv = realloc(_wenviron, (count + 2) * sizeof(wchar_t*))) == NULL) { free(name); free(mboption); free(woption); return -1; } _wenviron = wnewenv; if ((mbnewenv = realloc(_environ, (count + 2) * sizeof(char*))) == NULL) { free(name); free(mboption); free(woption); return -1; } _environ = mbnewenv; /* Set the last entry to our option. */ _wenviron[count] = woption; _environ[count] = mboption; _wenviron[count + 1] = NULL; _environ[count + 1] = NULL; } /* And finally update the OS environment. */ result = SetEnvironmentVariableW(name, epos + 1) ? 0 : -1; } free(name); return result; }