I want to display output on different screen, but how?
For example:
I want to display " hello world " on the first black screen, and when I press enter button, the old screen will disappear and another new black screen will display "thank you" .
Just how to do that in c?
Depending on what you want but just clear the screen after getting an enter.
puts("\033[2J"); will work on most terminal using VT100 escape codes.
clrscr() is a nonstandard function defined in <conio.h> that some older compilers use.
system("cls"); works with Windows and system("clear"); with Linux and is in <stdlib.h>.
These options would cover most environments that you would encounter when using C.
This is platform-dependent.
In Unix you have to call the corresponding APIs, Qt or GTK, to create a new terminal console.
In Windows you have to call WinAPI such as CreateConsole and such.
It would be easier if you only want to clear your current console. Using ASCII CSI escape sequence works on most Unix & Linux systems, just
printf("\x1B[2J");
Or in Windows, call
system("cls");
There's actually a more native approach which calls FillConsoleOutputCharacter and FillConsoleOutputAttribute, which introduces extra code that I'm not talking about here.
Related
I'm new to C and I came across this code and it was confusing me:
sprintf(banner1, "\e[37╔═╗\e[37┌─┐\e[37┌┐┌\e[37┌─┐\e[37┌─┐\e[37┌─┐\e[37┌─┐\e[37m\r\n");
sprintf(banner2, "\e[37╠═╝\e[37├─┤\e[37│││\e[37│ ┬\e[37├─┤\e[37├┤\e[37 ├─┤\e[37m\r\n");
sprintf(banner3, "\e[37╩ \e[37┴ ┴┘\e[37└┘\e[37└─┘\e[37┴ ┴\e[37└─┘\e[37┴ ┴\e[37m\r\n");
I was just confused as I don't know what do \e[37 and \r\n mean. And can I change the colors?
This looks like an attempt to use ANSI terminal color escapes and Unicode box drawing characters to write the word "PANGAEA" in a large, stylized, colorful manner. I'm guessing it's part of a retro-style BBS or MUD system, intended to be interacted with over telnet or ssh. It doesn't work, because whoever wrote it made a bunch of mistakes. Here's a corrected, self-contained program:
#include <stdio.h>
int main(void)
{
printf("\e[31m╔═╗\e[32m┌─┐ \e[33m┌┐┌\e[34m┌─┐\e[35m┌─┐\e[36m┌─┐\e[37m┌─┐\e[0m\n");
printf("\e[31m╠═╝\e[32m├─┤ \e[33m│││\e[34m│ ┬\e[35m├─┤\e[36m├┤ \e[37m├─┤\e[0m\n");
printf("\e[31m╩ \e[32m┴ ┴┘\e[33m┘└┘\e[34m└─┘\e[35m┴ ┴\e[36m└─┘\e[37m┴ ┴\e[0m\n");
return 0;
}
The mistakes were: using \r\n instead of plain \n, leaving out the m at the end of each and every escape sequence, and a number of typos in the actual letters (missing spaces and the like).
I deliberately changed sprintf(bannerN, ... to printf to make it a self-contained program instead of a fragment of a larger system, and changed the actual color codes used for each letter to make it a more interesting demo. When I run this program on my computer I get this output:
The program will only work on your computer if your terminal emulator supports both ANSI color escapes and printing UTF-8 with no special ceremony. Most Unix-style operating systems nowadays support both by default; I don't know about Windows.
I've wrote this very basic code-lines with colored output:
printf("\033[1;32m"); // boldgreen code: \033[1;32m according to:
http://web.theurbanpenguin.com/adding-color-to-your-output-from-c/
puts("Enter username:");
gets(user);
In my computer evreything works fine and I get colored output as expected:
but in other computers I get this Output:
\033[1;32mEnter username:
I have to say that all my #includes are fine, Im just doing copy-paste to another computer & if thats important Im using Visual Studio in both Computers.
seems like basic thing but I don't understand why thats happend.
Thanks for helpers.
Most terminals support colors. The problem is sending the right escape code. For the Windows command line, you have do a different escape sequence. There is a wikipedia entry that describes how to do an escape in different environments.
Is this possible?
I know it's possible in the command prompt using COLOR ##
but is it possible in C using bloodshed?
Thanks,
What operating system? What terminal do you have available? Note that this has nothing to do with C, let alone bloodshed. You output a string which the terminal may or may not choose to interpret as a color. You have to see how to do that with your terminal. The solution of course is not portable. One such example for a terminal supporting escape sequences is
printf("\\x1b[1;33mThis is yellow\\x1b[m(Back to default)\n");
You may be interested in ANSI terminal's color escape sequences
You may also want to look for libraries that do that for limited number of terminals. For example, ncurses could help you in Linux.
If you're on *nix, osx, or using cygwin msys on windows, your terminal should support the ANSI sequences Fred Larson mentions (not sure about osx). The normal windows terminal does not. But bloodshed can use cygwin, so you're in luck.
Here's an example:
#include <stdio.h>
#define BOLDMAGENTA "\033[1;35m"
#define BOLDGREEN "\033[1;32m"
int main(void) {
printf("%shello %sworld\n", BOLDMAGENTA, BOLDGREEN);
return 0;
}
Note that this leaves the terminal in bright green, but if your prompt sets colours, that will get reset.
Here's some explanation of ANSI escape codes:
http://en.wikipedia.org/wiki/ANSI_escape_code
Is it possible to color the console output in just plain ANSI C? Without an external library? Can this be done in Windows, Linux, or Mac OS X?
just plain ANSI C?
No. The C standard doesn't assume the stdout is a console or has color.
Can this be done in Windows, Linux, or Mac OS X?
Yes. See How can I print to the console in color on Mac OS X in a cross-platform manner? for Linux and Mac OS X.
For Windows, you may need to directly access the Console Functions if you want to avoid external libraries.
Yes, in Linux/ Mac it is possible using ANSI C89.
You can either manipulate the font and the color of the text.
using the following command:
printf("%c[0;00mHello, world!\n", 27); /* White color */
printf("%c[1;33mHello, world!\n", 27); /* Yellowish color */
printf("%c[1;34mHello, world!\n", 27); /* Blueish color */
Notice that the left part of the ";" (where the numbers 0, 1 are) manipulates the text font,
the right part of ";" manipulates the colors. You can experiment on your own and find out new colors.
This code compiles using "-ansi -pedantic" command with no warnings nor errors.
***** Edit *****
In Windows based systems you can achieve colorful console text/background of text using the following example:
#include <stdio.h>
#include <windows.h>
int main(void)
{
/* Point to our console */
HANDLE hConsole = GetStdHandle(STD_OUTPUT_HANDLE);
int i = 0;
/* Iterate through colors */
for(; i < 255; i++)
{ /* i stands for color type: could refer to actual text color or background color of text */
SetConsoleTextAttribute(hConsole, i);
printf("Colorful text");
}
getchar();
return 0;
}
Good luck!
in Linux this can be done, if you you know the shell-specific control codes / Escape sequences.
Linux/OSX/Unix
On posix systems you can use the ANSI escape sequences.
Windows
On windows it is a bit more complicated, there are multiple solutions:
Win32 API
Using the Win32 API to set the output color before printing to the console using SetConsoleTextAttribute and friends. This is a lot more cumbersome than simply embedding ANSI escape sequences in your strings, and requires you to handle Windows as a special case.
Windows ANSI.SYS and Replacement
Older version of windows contained ANSI.SYS, but this has been removed in later versions. ANSICON is a replacement for this that you can install to get ANSI color code support in the windows command prompt: https://github.com/adoxa/ansicon
Embeddable no external dependencies solution
Here is a project that can be easily integrated into any existing project without relying on ANSI.SYS or ANSICON being installed.
It takes a string containing ANSI escape sequences and translates them to the relevant Win32 equivalent API functions: https://github.com/mattn/ansicolor-w32.c
It is true that ISO C knows nothing about the console being capable of displaying colors, however there is an ANSI norm for console capabilities management, based on escape character controls. This works transparently in Linux and Mac OS X, however it fails in Windows, in which you need to use the primitives of the Win32 API.
You can find below a very simple library that allows to clear the screen, show colors and locate the cursor in a specific coordinate, in a multiplatform way (Win32 & Unix-like systems).
It comes with plain C source files (.c and .h), doxygen documentation in Spanish (doc/), and a simple demo (main.c)
http://github.com/Baltasarq/cscrutil/
I'm looking to follow along with The C Programming Language (Second Addition) on a machine running Vista.
So far, I've found Dev-C++ the easiest IDE to do this in. However, I still have one problem. Whenever I run my compiled code, for example: a simple hello world program, it runs, but the console window just flickers on the screen, and I can't see the output.
How can I see an the output of my C programs using Dev-C++? I found a C++ specific solution, System("pause"), and a really ugly C solution, while looping fflush(stdout), but nothing nice and pretty.
I put a getchar() at the end of my programs as a simple "pause-method". Depending on your particular details, investigate getchar, getch, or getc
In Windows when a process terminates, the OS closes the associated window. This happens with all programs (and is generally desirable behaviour), but people never cease to be surprised when it happens to the ones they write themselves.
I am being slightly harsh perhaps; many IDE's execute the user's process in a shell as a child process, so that it does not own the window so it won't close when the process terminates. Although this would be trivial, Dev-C++ does not do that.
Be aware that when Dev-C++ was popular, this question appeard at least twice a day on Dev-C++'s own forum on Sourceforge. For that reason the forum has a "Read First" thread that provides a suggested solution amongst solutions to many other common problems. You should read it here.
Note that Dev-C++ is somewhat old and no longer actively maintained. It suffers most significantly from an almost unusable and very limited debugger integration. Traffic on the Dev-C++ forum has been dropping off since the release of VC++ 2005 Express, and is now down to a two or three posts a week rather than the 10 or so a day it had in 2005. All this suggest that you should consider an alternative tool IMO.
Use #include conio.h
Then add getch(); before return 0;
The easiest thing to do is to run your program directly instead of through the IDE. Open a command prompt (Start->Run->Cmd.exe->Enter), cd to the folder where your project is, and run the program from there. That way, when the program exits, the prompt window sticks around and you can read all of the output.
Alternatively, you can also re-direct standard output to a file, but that's probably not what you are going for here.
For Dev-C++, the bits you need to add are:-
At the Beginning
#include <stdlib.h>
And at the point you want it to stop - i.e. before at the end of the program, but before the final }
system("PAUSE");
It will then ask you to "Press any key to continue..."
Add this to your header file #include
and then in the end add this line : getch();
You can open a command prompt (Start -> Run -> cmd, use the cd command to change directories) and call your program from there, or add a getchar() call at the end of the program, which will wait until you press Enter. In Windows, you can also use system("pause"), which will display a "Press enter to continue..." (or something like that) message.
Add a line getchar(); or system("pause"); before your return 0; in main function.
It will work for you.
;
It works...
#include <iostream>
using namespace std;
int main ()
{
int x,y; // (Or whatever variable you want you can)
your required process syntax type here then;
cout << result
(or your required output result statement); use without space in getchar and other syntax.
getchar();
}
Now you can save your file with .cpp extension and use ctrl + f 9 to compile and then use ctrl + f 10 to execute the program.
It will show you the output window and it will not vanish with a second Until you click enter to close the output window.
i think you should link your project in console mode
just press Ctrl+h and in General tab select console.
When a program is not showing or displaying an output on the screen, using system("pause"); is the solution to it on a Windows profile.
The use of line system("PAUSE") will fix that problem and also include the pre processor directory #include<stdlib.h>.
Well when you are writing a c program and want the output log to stay instead of flickering away you only need to import the stdlib.h header file and type "system("PAUSE");" at the place you want the output screen to halt.Look at the example here.The following simple c program prints the product of 5 and 6 i.e 30 to the output window and halts the output window.
#include <stdio.h>
#include <stdlib.h>
int main()
{
int a,b,c;
a=5;b=6;
c=a*b;
printf("%d",c);
system("PAUSE");
return 0;
}
Hope this helped.