/**
* Persists shell state. If fails, calls {@link ru.fizteh.fivt.students.fedorov_andrew
* .databaselibrary.shell.ShellState#prepareToExit(int)} with non zero exit code.
*/
private void persistSafelyAndPrepareToExit() throws ExitRequest {
try {
shellState.persist();
shellState.prepareToExit(0);
} catch (ExitRequest request) {
throw request;
} catch (Exception exc) {
Log.log(Shell.class, exc, "Failed to persist shell state");
shellState.prepareToExit(1);
}
}
/** Prepares shell for further command interpretation */
private void init() throws TerminalException {
Log.log(Shell.class, "Shell starting");
try {
shellState.init(this);
} catch (Exception exc) {
Utility.handleError(exc.getMessage(), exc, true);
}
commandMap = shellState.getCommands();
}
/** Execute commands from input stream. Commands are awaited till the-end-of-stream. */
public int run(InputStream stream) throws TerminalException {
interactive = true;
if (stream == null) {
throw new IllegalArgumentException("Input stream must not be null");
}
boolean exitRequested = false;
try (BufferedReader reader =
new BufferedReader(new InputStreamReader(stream), READ_BUFFER_SIZE)) {
while (true) {
System.out.print(shellState.getGreetingString());
String str = reader.readLine();
// End of stream.
if (str == null) {
break;
}
List<String[]> commands = splitCommandsString(str);
try {
for (String[] command : commands) {
execute(command);
}
} catch (TerminalException exc) {
// Exception is already handled.
}
}
} catch (IOException | ParseException exc) {
exitRequested = true;
Utility.handleError("Error in input stream: " + exc.getMessage(), exc, true);
// No need to cleanup - work has not been started.
} catch (ExitRequest request) {
exitRequested = true;
return request.getCode();
} finally {
if (!exitRequested) {
try {
persistSafelyAndPrepareToExit();
} catch (ExitRequest request) {
return request.getCode();
}
}
}
// If all contracts are honoured, this line is unreachable.
throw new AssertionError("No exit request performed");
}
/**
* Execute commands from command line arguments. Note that command line arguments are first
* concatenated into a single line then split and parsed.
*
* @param args Array of commands. If an error happens during execution of one of the commands in
* the sequence, next commands will not be executed.
* @return Exit code. 0 means normal status, anything else - abnormal termination (error).
*/
public int run(String[] args) throws TerminalException {
try {
interactive = false;
try {
List<String[]> commands = splitCommandsString(String.join(" ", args));
for (String[] command : commands) {
execute(command);
}
} catch (TerminalException exc) {
// Exception already handled.
shellState.prepareToExit(1);
} catch (ParseException exc) {
Utility.handleError("Cannot parse command arguments: " + exc.getMessage(), exc, true);
}
persistSafelyAndPrepareToExit();
} catch (ExitRequest request) {
return request.getCode();
}
// If all contracts are honoured, this line is unreachable.
throw new AssertionError("No exit request performed");
}
