so I've decided to install Eclipse to use for my C programming. I wanted to write a small program, just to test that everything works, however it seems that Eclipse won't let me scan in any C inputs. For any other program, that requires no input, it works fine but it seems for some reason Eclipse won't run any program that requires a use to input. I'm running the programs by going to Run->Run As-> Local C/C++ Applications. I've also tried running these programs through the command line, and they turn out fine. Any ideas?
Code:
#include <stdio.h>
int main(void) {
int length, width, height, volume, weight;
printf("Enter the length of box: ");
scanf("%d", &length);
printf("Enter the height of box: ");
scanf("%d", &height);
printf("Enter the width of box: ");
scanf("%d", &width);
volume = length * width * height;
weight = (volume+165)/166;
printf("Volume(cubic inches) %d\n", volume);
printf("Dimensional weight(pounds): %d\n", weight);
return 0;
}
Installed Packages:
After I try to run these programs, nothing appears in the console window, but after I press stop this is what comes out:
Here's a better pic: http://i.imgur.com/zgV1r.png
Try adding an fflush(stdout) after each of your printf() calls as suggested here.
Here is some more discussion of why fflush is required.
Related
I try This code
#include <stdio.h>
int main() {
int testInteger;
printf("Enter an integer: \n");
scanf("%d", &testInteger);
return 0;
}
But in Netbeans, I can't Run this code because It only blank output
Like this
I have same err in VS code but I fix it with run in terminal
Can you help me
This problem is about Netbean's internal terminal/console section. The internal console is not able to run scanf function. So use an external terminal for your project. To do this:
first right click on your project, and select properties.
In that window select "Run" tab at the bottom.
in there, there is "Console Type", change this console type from "internal terminal" to "external terminal".
That is all.
try this code
Add a space in scanf
#include <stdio.h>
int main() {
int testInteger;
printf("Enter an integer: \n");
scanf(" %d", &testInteger);
return 0;
}
I have recently started to learn programming in c language. I installed Mingw and vista studio code for the same. However, when I wrote my first program it just keeps showing error and won't run. I made a program to calculate simple interest. I have checked the syntax multiple times. Please help in pointing out the error.
#include <stdio.h>
int main()
{
int p, n;
float r, si;
printf("Enter principal\n Enter no. of years\n Enter rate\n");
scanf("%d, %d, %f", &p, &n, &r);
si = p * r * n / 100;
printf("%f\n", si);
return 0;
}
Picture of the error
The gcc executable is not on your PATH, and so the system can't find it (and thus not execute it)
Update the PATH environment variable so that the directory where gcc is installed is part of it.
See here for how to do that.
I can't properly run/debug my code in VS Code using the C language. I've installed C/C++ package on VSC, Mingw & applied the path for Mingw. All my files are running .c format as well.
Only the last part of my code keeps crashing in VSC, when I run this same code on website compilers, it works!
Here is my code:
#include <stdio.h>
int main(void) {
int num1;
int num2;
printf("Enter a number: ");
scanf("%d", &num1);
printf("Enter another number: ");
scanf("%d", &num2);
printf("Answer: %d ", num1 + num2);
return 0;
}
That last printf is where VSC just shuts down the output window, so I never get to see the end result of my code. Anyone have any solutions to fix this? It'd be greatly appreciated!
When you run your console program from Visual Studio, it opens a terminal window, runs the program and the terminal window closes automatically when the program exits. This is a classic problem with the Microsoft Windows platform that they do not seem to care about despite millions of newbie programmers like you experiencing the same problem.
If you open the terminal window yourself, by running the CMD command from the start menu, you will be able to run your program manually after changing the current directory to that of the program binary.
To prevent the terminal window from closing immediately when running directly from Visual Studio, you should add 2 getchar(); statements before returning from main() to wait for user input and get a chance to see the output. Just reading a single byte with getchar() will not suffice because it will just read the pending newline entered by the user in response to the second prompt.
Also note that it is preferable to output a trailing newline to ensure the output is properly flushed on some legacy systems:
printf("Answer: %d\n", num1 + num2);
Here is a modified program you can test:
#include <stdio.h>
int main(void) {
int num1 = 0, num2 = 0;
printf("Enter a number: ");
scanf("%d", &num1);
printf("Enter another number: ");
scanf("%d", &num2);
printf("Answer: %d\n", num1 + num2);
getchar(); // read the pending newline
getchar(); // read at least another byte from the user.
return 0;
}
run you program from the console:
In the search box type cmd
cd \path_to_your_executable
run your program.
I'm trying to execute a program from the book by K. N. King "C Programming, A Modern Approach, 2 Edition", in NetBeans 8.0.2, using MinGW compiler. The program looks like this:
#include <stdio.h>
int main(void) {
int height, length, width, volume, weight;
printf("Enter height of box: ");
scanf("%d", &height);
printf("Enter length of box: ");
scanf("%d", &length);
printf("Enter width of box: ");
scanf("%d", &width);
volume = height * length * width;
weight = (volume + 165) / 166;
printf("Volume (cubic inches): %d\n", volume);
printf("Dimensional weight (pounds): %d\n", weight);
return 0;
}
So, I press "Run Project", the program builds successfully without any errors, then it begins to run and nothing happens, no console or something like that appears to input data like height, length, etc.
In the output window, after the program builded, it begins to run and nothing is displayed in the window except for a thick cursor. When I press any button being in that window, the program ends and this is what is displayed:
Enter height of box: Enter length of box: Enter width of box: Volume (cubic inches): 0 Dimensional weight (pounds): 0
RUN SUCCESSFUL (total time: 6s)
I'm completely new to C, so I don't know, what should appear when the program runs. When launching programs written in Python the console appeared, and now I'm confused.
When I tried to debug, it builded successfully again and then the console appeared with the line: "Enter height of box: ", so it worked like I thought it should work, but I don't think this is the proper way to run programs.
stdio streams are buffered. You need to fflush() stdout before using stdin, if you want the output to be displayed before the program blocks waiting on input. Alternatively, you can end all output lines with '\n', as newline implicitly flushes the output.
Edit: If you're entering data that scanf() cannot match using %d, such as alphabetic characters, scanf() will fail. You can check for this failure by comparing the return value of scanf() with the number of matches you expected (one in this case). As it stands, you don't check for this, and the characters stay in the input buffer, where the next scanf() will again try and fail to match them.
I'm capturing some user input and saving it to both a struct and a file.
For each field, I first write a prompt using printf, and then capture data to the struct using scanf, and finally write to file using fprintf.
The program works fine, but only on one computer, one scanf executes before its corresponding printf.
Here's the core of the problem:
printf("\n color: ");
scanf("%s",&robot1.color);
fputs(robot1.color, f);
fputs("\n",f);
printf("\n energy: ");
scanf("%d",&robot1.energy);
fprintf(f,"%d",robot1.energy);
fputs("\n",f);
printf("\n height: ");
scanf("%f",&robot1.height);
fprintf(f,"%.2f",robot1.height);
fputs("\n",f);
printf("\n weight: ");
scanf("%f",&robot1.weight);
fprintf(f,"%.2f",robot1.weight);
fputs("\n",f);
I tested it on two Windows PCs using Dev-C++, and on a Mac using GCC. One of the Windows machines is the one causing all this mess.
The correct execution (user input included) is:
color: red
energy: 100
height: 30.5
weight: 500.0
But in the troublesome computer, after I input the energy value, it shows nothing, and to continue I have to input the height value.
After that, I see the height and weight prompts, and finish by capturing the weight:
color: red
energy: 100
30.5
height:
weight: 500.0
The file is written correctly in all cases so, why is only one computer having trouble with scanf and printf?
The struct definition is:
typedef struct roboto
{
char name[10];
char color[10];
int energy;
float height;
float weight;
}robot;
I am guessing its an issue with stdout not being flushed before the user is being prompted for input. To fix this you could try flushing stdout after each print statement using fflush(stdout);. For example:
printf("\n color: ");
fflush(stdout);
scanf("%s",&robot1.color);
fputs(robot1.color, f);
fputs("\n",f);
The standard output is buffered so you cannot be sure when it will be written.
Call fflush(stdout) to force the output to be written after calling printf, then you can be sure that the output will be written.
Maybe checking the return value from scanf would give you some clues. Ignoring that value is just asking for trouble.