system pause - Why is it wrong

Question

Here s a question that I don t quite understand   The command  system  pause    is taught to new programmers as a way to pause a program and wait for a keyboard input to continue  However  it seems to be frowned on by many veteran programmers as something that should not be done in varying degrees   Some people say it is fine to use  Some say it is only to be used when you are locked in your room and no one is watching  Some say that they will personally come to your house and kill you if you use it    I  myself am a new programmer with no formal programming training  I use it because I was taught to use it  What I don t understand is that if it is not something to be used  then why was I taught to use it  Or  on the flip side  is it really not that bad after all   What are your thoughts on this subject

User · Answer

You can use std  cin get   from iostream    include  lt iostream gt     std  cout  std  cin using namespace std   int main        do        cout  lt  lt    n   lt  lt   Press the Enter key to continue         while  cin get        n        return 0      Besides  system  pause   is slow  and includes a file you probably don t need  stdlib h  It is platform-dependent  and actually calls up a  virtual  OS

User · Answer

In summary  it has to pause the programs execution and make a system call and allocate unnecessary resources when you could be using something as simple as cin get    People use System  PAUSE   because they want the program to wait until they hit enter to they can see their output  If you want a program to wait for input  there are built in functions for that which are also cross platform and less demanding   Further explanation in this article

User · Answer

the pro s to using system  PAUSE    while creating the small portions of your program is for debugging it yourself   if you use it to get results of variables before during and after each process you are using to assure that they are working properly   After testing and moving it into full swing with the rest of the solution you should remove these lines   it is really good when testing an user-defined algorithm and assuring that you are doing things in the proper order for results that you want   In no means do you want to use this in an application after you have tested it and assured that it is working properly   However it does allow you to keep track of everything that is going on as it happens   Don t use it for End-User apps at all

User · Answer

It s slow  It s platform dependent  It s insecure   First  What it does  Calling  system  is literally like typing a command into the windows command prompt  There is a ton of setup and teardown for your application to make such a call - and the overhead is simply ridiculous   What if a program called  pause  was placed into the user s PATH  Just calling system  pause   only guarantees that a program called  pause  is executed  hope that you don t have your executable named  pause     Simply write your own  Pause    function that uses  getch  OK  sure   getch is platform dependent as well  note  it s defined in  conio h   - but it s much nicer than system   if you are developing on Windows and it has the same effect  though it is your responsibility to provide the text with cout or so    Basically  why introduce so many potential problems when you can simply add two lines of code and one include and get a much more flexible mechanism

User · Answer

system  pause        is wrong because it s part of Windows API and so it won t work in other operation systems     You should try to use just objects from C   standard library  A better solution will be to write     cin get    return 0    But it will also cause problems if you have other cins in your code  Because after each cin  you ll tap an Enter or  n which is a white space character  cin ignores this character and leaves it in the buffer zone but cin get    gets this remained character  So the control of the program reaches the line return 0 and the console gets closed before letting you see the results  To solve this  we write the code as follows     cin ignore      cin get      return 0

User · Answer

Because it is not portable     pause   is a windows   dos only program  so this your code won t run on linux   Moreover  system is not generally regarded as a very good way to call another program - it is usually better to use CreateProcess or fork or something similar

User · Answer

Here s one reason you shouldn t use it  it s going to piss off most anti-virus programs running on Windows if you re passing the program over to another machine because it s a security threat  Even if your program only consists of a simple cout  lt  lt   hello world n   system  pause    It s resource heavy and the program gets access to the cmd command  which anti viruses see as a threat

User · Answer

Using system  pause    is Ungood Practice trade  because   It s completely unnecessary  To keep the program s console window open at the end when you run it from Visual Studio  use Ctrl F5 to run it without debugging  or else place a breakpoint at the last right brace   of main  So  no problem in Visual Studio  And of course no problem at all when you run it from the command line  It s problematic  amp  annoying when you run the program from the command line  For interactive execution you have to press a key at the end to no purpose whatsoever  And for use in automation of some task that pause is very much undesired  It s not portable  Unix-land has no standard pause command    The pause command is an internal cmd exe command and can t be overridden  as is erroneously claimed in at least one other answer  I e  it s not a security risk  and the claim that AV programs diagnose it as such is as dubious as the claim of overriding the command  after all  a C   program invoking system is in position to do itself all that the command interpreter can do  and more   Also  while this way of pausing is extremely inefficient by the usual standards of C   programming  that doesn t matter at all at the end of a novice s program   So  the claims in the horde of answers before this are not correct  and the main reason you shouldn t use system  pause   or any other wait command at the end of your main  is the first point above  it s completely unnecessary  it serves absolutely no purpose  it s just very silly

User · Answer

For me it doesn t make sense in general to wait before exiting without reason  A program that has done its work should just end and hand over its resources back to its creator   One also doesn t silently wait in a dark corner after a work day  waiting for someone tipping ones shoulder

User · Answer

It s frowned upon because it s a platform-specific hack that has nothing to do with actually learning programming  but instead to get around a feature of the IDE OS - the console window launched from Visual Studio closes when the program has finished execution  and so the new user doesn t get to see the output of his new program   Bodging in System  pause   runs the Windows command-line  pause  program and waits for that to terminate before it continues execution of the program - the console window stays open so you can read the output   A better idea would be to put a breakpoint at the end and debug it  but that again has problems

User · Answer

It s all a matter of style  It s useful for debugging but otherwise it shouldn t be used in the final version of the program  It really doesn t matter on the memory issue because I m sure that those guys who invented the system  pause   were anticipating that it d be used often  In another perspective  computers get throttled on their memory for everything else we use on the computer anyways and it doesn t pose a direct threat like dynamic memory allocation  so I d recommend it for debugging code  but nothing else

User · Answer

slow  it has to jump through lots of unnecessary Windows code and a separate program for a simple operation  not portable  dependent on the pause program  not good style  making a System call should only be done when really necessary more typing  System  pause   is longer than getchar     a simple getchar   should do just fine

User · Answer

As listed on the other answers  there are many reasons you can find to avoid this  It all boils down to one reason that makes the rest moot  The System   function is inherently insecure untrusted  and should not be introduced into a program unless necessary   For a student assignment  this condition was never met  and for this reason I would fail an assignment without even running the program if a call to this method was present   This was made clear from the start

[c++] system("pause"); - Why is it wrong?

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