导入导出的返回状态 ERRORLEVEL-ios中NSUserDefaults的使用-输出流效率测试

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▪导入导出的返回状态 ERRORLEVEL 在论坛上有人问了这样一个问题，就是imp，exp的返回值是什么？这个问题问的比较偏，但是细想一下，在做bat自动导入的时候肯定会用的着，于是查询了一下关于在windows编写导出导入脚本.........

▪ios中NSUserDefaults的使用创建一个user defaults方法有多个，最简单得快速创建方法: NSUserDefaults *accountDefaults = [NSUserDefaults standardUserDefaults]; 添加数据到 user defaults: [accountDefaults setObject:nameField.text forKey:UserDefaultN.........

▪输出流效率测试这个问题Effective STL中有讲过，但当时没怎么留意。今天编程时由于涉及到输出的效率，所以做了一测试。测试对象： 1.cout<< 2.ostream_iterator 3.ostreambuf_iterator 4.printf 5.cout.put 6.rdbuf()->sput.........

[1]导入导出的返回状态 ERRORLEVEL

来源: 互联网发布时间: 2013-11-10

在论坛上有人问了这样一个问题，就是imp，exp的返回值是什么？这个问题问的比较偏，但是细想一下，在做bat自动导入的时候肯定会用的着，于是查询了一下关于在windows编写导出导入脚本的相关问题，在

http://www.dba-oracle.com/t_scripts_windows_export.htm

找到了一些头绪，代码如下：

Lets examine Hunter's oracle_export.bat Oracle Windows script. Note that he builds the exp parfile arguments into a DOS variable called %PARFILE%, just like you can invoke Oracle directly from the DOS prompt (on one line only) : e.g.

c:> exp=%PARFILE%:

REM +--------------------------------------------------------------------------+
REM | VALIDATE COMMAND-LINE PARAMETERS                                         |
REM +--------------------------------------------------------------------------+

if (%1)==() goto USAGE
if (%2)==() goto USAGE
if (%3)==() goto USAGE

REM +--------------------------------------------------------------------------+
REM | VALIDATE ENVIRONMENT VARIABLES                                           |
REM +--------------------------------------------------------------------------+

REM set ORABACKUP=C:\oracle\orabackup\JEFFDB\export
REM set ORALOG=C:\oracle\custom\oracle\log
REM set ORATMP=C:\oracle\custom\oracle\temp

if (%ORALOG%)==() goto ENV_VARIABLES
if (%ORATMP%)==() goto ENV_VARIABLES
if (%ORABACKUP%)==() goto ENV_VARIABLES

REM +--------------------------------------------------------------------------+
REM | DECLARE ALL GLOBAL VARIABLES.                                            |
REM +--------------------------------------------------------------------------+

set FILENAME=export_backup_online_full_9i
set DB_USERNAME=%1%
set DB_PASSWORD=%2%
set TNS_ALIAS=%3%
set PARFILE=%ORATMP%\%FILENAME%_%TNS_ALIAS%.parfile
set LOGFILE=%ORALOG%\%FILENAME%_%TNS_ALIAS%.log
set DUMPFILE=%ORABACKUP%\exp_full_%TNS_ALIAS%.dmp

REM +--------------------------------------------------------------------------+
REM | REMOVE OLD LOG AND PARAMETER FILE(S).                                    |
REM +--------------------------------------------------------------------------+

del /q %PARFILE%
del /q %LOGFILE%

REM +--------------------------------------------------------------------------+
REM | WRITE EXPORT PARAMETER FILE.                                             |
REM +--------------------------------------------------------------------------+

echo userid=%DB_USERNAME%/%DB_PASSWORD%@%TNS_ALIAS% > %PARFILE%
echo buffer=50000000 >> %PARFILE%
echo file=%DUMPFILE% >> %PARFILE%
echo compress=n >> %PARFILE%
echo grants=y >> %PARFILE%
echo indexes=y >> %PARFILE%
echo direct=no >> %PARFILE%
echo log=%LOGFILE% >> %PARFILE%
echo rows=y >> %PARFILE%
echo consistent=y >> %PARFILE%
echo full=y >> %PARFILE%
REM echo owner=(SCOTT) >> %PARFILE%
REM echo tables=(EMP, DEPT) >> %PARFILE%
echo triggers=y >> %PARFILE%
echo statistics=none >> %PARFILE%
echo constraints=y >> %PARFILE%

REM +--------------------------------------------------------------------------+
REM | MOVE OLD EXPORT (DUMP) FILE.                                             |
REM +--------------------------------------------------------------------------+

del /q %DUMPFILE%.backup
move %DUMPFILE% %DUMPFILE%.backup

REM +--------------------------------------------------------------------------+
REM | PERFORM EXPORT.                                                          |
REM +--------------------------------------------------------------------------+

exp parfile=%PARFILE%

REM +--------------------------------------------------------------------------+
REM | SCAN THE EXPORT LOGFILE FOR ERRORS.                                      |
REM +--------------------------------------------------------------------------+

echo ...
echo Analyzing log file for EXP- errors...
findstr /I /C:"EXP-" %LOGFILE%
if errorlevel 0 if not errorlevel 1 echo EXP- Errors: %FILENAME% %TNS_ALIAS% %COMPUTERNAME% %DATE% %TIME% %LOGFILE%

echo ...
echo Analyzing log file for ORA- errors...
findstr /I /C:"ORA-" %LOGFILE%
if errorlevel 0 if not errorlevel 1 echo ORA- Errors: %FILENAME% %TNS_ALIAS% %COMPUTERNAME% %DATE% %TIME% %LOGFILE%

echo ...
echo Analyzing log file for warnings...
findstr /I /C:"Export terminated successfully with warnings" %LOGFILE%
if errorlevel 0 if not errorlevel 1 echo WARNING: %FILENAME% %TNS_ALIAS% %COMPUTERNAME% %DATE% %TIME% %LOGFILE%

echo ...
echo Analyzing log file for errors...
findstr /I /C:"Export terminated unsuccessfully" %LOGFILE%
if errorlevel 0 if not errorlevel 1 echo ERROR: %FILENAME% %TNS_ALIAS% %COMPUTERNAME% %DATE% %TIME% %LOGFILE%

echo ...
echo END OF FILE REPORT
echo Filename      : %FILENAME%
echo Database      : %TNS_ALIAS%
echo Hostname      : %COMPUTERNAME%
echo Date          : %DATE%
echo Time          : %TIME%
echo EXP Log File : %LOGFILE%

重点在SCAN THE EXPORT LOGFILE FROM ERRORS里面，看到了有这样一些判断IF ERRORLEVEL，这个就是判断是是否正确导出的标志，在MOS里面看到这样一些描述：

A. Successful export/import.
-------------------------
Result : Export terminated successfully without warnings
Import terminated successfully without warnings
Exit Code : EX_SUCC
Exit Level: 0

[2]ios中NSUserDefaults的使用

来源: 互联网发布时间: 2013-11-10

创建一个user defaults方法有多个，最简单得快速创建方法:

NSUserDefaults *accountDefaults = [NSUserDefaults standardUserDefaults];

添加数据到 user defaults:

[accountDefaults setObject:nameField.text forKey:UserDefaultNameKey];

也可以添加基本数据类型int, float, bool等，有相应得方法

[accountDefaults setBool:YES forKey:UserDefaultBoolKey];

从user defaults中获取数据:

[accountDefaults objectForKey:NCUserDefaultNameKey]  
[accountDefaults boolForKey: UserDefaultBoolKey];

要点：

NSUserDefaults非常好用，并不需要用户在程序中设置NSUserDefaults的全局变量，需要在哪里使用NSUserDefaults的数据，那么就在哪里创建一个NSUserDefaults对象，然后进行读或者写操作。

针对同一个关键字对应的对象或者数据，可以对它进行重写，重写之后关键字就对应新的对象或者数据，旧的对象或者数据会被自动清理。

以下是一个我自己写的例子,通过checkBtn按钮进行保存用户名和密码：

图片一：保存数据之前；或者上一次没有保存数据，第二次启动的界面

图片二：保存了数据，第二次打开所看到的启动初始界面

- (void)defaultCheck:(id)sender
{   
 NSLog(@" check按钮被按下   ");
 NSUserDefaults *accountDefaults = [NSUserDefaults standardUserDefaults];
 if ([accountDefaults boolForKey:NCUserDefaultBoolForRegister] == NO)
 {
  ((UIButton*)sender).selected = YES;
  [accountDefaults setBool:YES forKey:NCUserDefaultBoolForRegister];
  [accountDefaults setObject:nameField.text forKey:NCUserDefaultNameKey];
  [accountDefaults setObject:pwdField.text forKey:NCUserDefaultPasswordKey];
 }
 else {//YES
  ((UIButton*)sender).selected = NO;
  [accountDefaults setBool:NO forKey:NCUserDefaultBoolForRegister];
  [accountDefaults setObject:nil forKey:NCUserDefaultNameKey];
  [accountDefaults setObject:nil forKey:NCUserDefaultPasswordKey];
 }
}

- (void)loadView {
  [super loadView];

 nameField = [[UITextField alloc]initWithFrame:CGRectMake(0, 0, 100, 30)];
 pwdField = [[UITextField alloc]initWithFrame:CGRectMake(0, 0, 100, 30)];
 [nameField setCenter:CGPointMake(160, 100)];
 [pwdField setCenter:CGPointMake(160, 150)];
 
 NSUserDefaults *accountDefaults = [NSUserDefaults standardUserDefaults];
 
        //存的是bool值一定要用boolForKey:获取
        //如果之前已经保存了User Defaults,那么在读取的时候就要将数据读取出来，显示在用户名和密码框中（

[3]输出流效率测试

来源: 互联网发布时间: 2013-11-10

这个问题Effective STL中有讲过，但当时没怎么留意。今天编程时由于涉及到输出的效率，所以做了一测试。

测试对象：

1.cout<<

2.ostream_iterator

3.ostreambuf_iterator

4.printf

5.cout.put

6.rdbuf()->sputn

测试平台：

1.6GHz处理器

测试代码：

#include <iostream>
#include <iterator>
#include <cstdio>
#include <ctime>
#include <iomanip>
using namespace std;

int main()
{
   /*以10000个'a'作为输出目标*/
   char a[10000] = {'a'};

   clock_t start1, end1, start2, end2, start3, end3, start4, end4, start5, end5, start6, end6;

   /*测试ostream_iterator*/
   start1 = clock();
   copy(a, a + 10000, ostream_iterator<char>(cout));
   end1 = clock();

   /*测试ostreambuf_iterator*/
   start2 = clock();
   copy(a, a + 10000, ostreambuf_iterator<char>(cout));
   end2 = clock();

   /*测试cout<<*/
   start3 = clock();
   for (char x: a)
	   cout << x;
   end3 = clock();

   /*测试printf*/
   start4 = clock();
   for (char x: a)
	   printf("%c", x);
   end4 = clock();

   /*测试cout.put*/
   start5 = clock();
   for (char x: a)
	   cout.put(x);
   end5 = clock();

   /*测试rdbuf()->sputn*/
   start6 = clock();
   cout.rdbuf()->sputn(a, 10000);
   end6 = clock();

   cout << endl;
   cout << setw(25) << "ostream_iterator: " << static_cast<double>(end1 - start1) / CLOCKS_PER_SEC << " seconds"<< endl;
   cout << setw(25) << "ostreambuf_iterator: " << static_cast<double>(end2 - start2) / CLOCKS_PER_SEC << " seconds"<< endl;
   cout << setw(25) <<  "cout<<: " << static_cast<double>(end3 - start3) / CLOCKS_PER_SEC << " seconds"<< endl;
   cout << setw(25) <<  "printf: " << static_cast<double>(end4 - start4) / CLOCKS_PER_SEC << " seconds"<< endl;
   cout << setw(25) <<  "cout.put: " << static_cast<double>(end5 - start5) / CLOCKS_PER_SEC << " seconds"<< endl;
   cout << setw(25) <<  "rdbuf()->sputn: " << static_cast<double>(end6 - start6) / CLOCKS_PER_SEC << " seconds"<< endl; 
   return 0;
}

测试结果：

1.用MinGW编译

ostream_iterator: 6.806 seconds ostreambuf_iterator: 0.142 seconds cout<<: 6.712 seconds printf: 7.173 seconds cout.put: 6.652 seconds rdbuf()->sputn: 0.118 seconds

2.用Borland C++编译

ostream_iterator: 5.569 seconds ostreambuf_iterator: 0.203 seconds cout<<: 4.789 seconds printf: 4.493 seconds cout.put: 4.555 seconds rdbuf()->sputn: 0.141 seconds

3.用VS2012编译

ostream_iterator: 4.809 seconds ostreambuf_iterator: 4.659 seconds cout<<