I'd like to develop character based program with Tiny C Compiler.
The putc works fine, but I want to print the character in a specific place on the character screen. Like in turbo pascal with gotoxy. Is there such a possibility?
I'm looking through a bunch of header files, but couldn't find one.
#include <stdio.h>
int main(int argc, char **argv) {
// gotoxy(1,15); // ???????
putc(65,stdout);
}
I am currently trying to check the number of arguments supplied in the command line before my program executes. However, when I write argc within the main function, argc is underlined in red. When I hover over argc, I see a message saying, "Symbol argc could not be resolved." What could be happening?
int main(int argc, char **argv)
{
printf("%d", argc);
}
I can access argv without any issues. I am using the GCC C Compiler and working in Eclipse in a Unix environment.
EDIT: Renaming argc to something else, restarting Eclipse, and then changing that name back to argc resolved my issue. Thank you to everyone who helped me.
I have created wit_func.exe using Matlab. Now I am trying to run the program using C.
I have written the following code:
#include <stdio.h>
#include<stdlib.h>
int main(int argc, char **argv)
{
int r;
r=system("C:\\Users\\mails\\OneDrive\\Documents\\MATLAB\\Testing for the executable files\\wit_func.exe");
printf("%d",r);
getchar();
return 0;
}
I provided the path to that .exe file. I getting this following output:
'C:\Users\mails\OneDrive\Documents\MATLAB\Testing' is not recognized as an internal or external command,
operable program or batch file.
1
I also need to pass some integer arguments to this executable file. Can somebody help me run this program properly?
#include "hmap.h"
int main(char* argv[], int argc)
{
printf("%s", argv[0]); <---- fails here
system("pause");
fileOpen(argv[1]);
return 0;
}
I am using MSVS 2012. I'm wondering if I'm using the command line arguments wrong. The text file is in the same folder. All my header file has is the #include libraries I will using, some #define's I'll be using, and extern function prototypes.
When I run the program it says "expand.exe has stopped working...."
I usually program in a Linux environment using GCC but I'm trying to learn MSVS environment. Getting a little frustrated on how much of a hassle to input command line arguments :.
I think the arguments for main() are around the wrong way.
That is, the first argument should be the argument count (argv), and the second one the argument vector (argv).
int main(int argc, char* argv[]) {}
It fails because a subscript should be used only with an array or pointer.
I have made little program for computing pi (π) as an integral. Now I am facing a question how to extend it to compute an integral, which will be given as an extra parameter when starting an application. How do I deal with such a parameter in a program?
When you write your main function, you typically see one of two definitions:
int main(void)
int main(int argc, char **argv)
The second form will allow you to access the command line arguments passed to the program, and the number of arguments specified (arguments are separated by spaces).
The arguments to main are:
int argc - the number of arguments passed into your program when it was run. It is at least 1.
char **argv - this is a pointer-to-char *. It can alternatively be this: char *argv[], which means 'array of char *'. This is an array of C-style-string pointers.
Basic Example
For example, you could do this to print out the arguments passed to your C program:
#include <stdio.h>
int main(int argc, char **argv)
{
for (int i = 0; i < argc; ++i)
{
printf("argv[%d]: %s\n", i, argv[i]);
}
}
I'm using GCC 4.5 to compile a file I called args.c. It'll compile and build a default a.out executable.
[birryree#lilun c_code]$ gcc -std=c99 args.c
Now run it...
[birryree#lilun c_code]$ ./a.out hello there
argv[0]: ./a.out
argv[1]: hello
argv[2]: there
So you can see that in argv, argv[0] is the name of the program you ran (this is not standards-defined behavior, but is common. Your arguments start at argv[1] and beyond.
So basically, if you wanted a single parameter, you could say...
./myprogram integral
A Simple Case for You
And you could check if argv[1] was integral, maybe like strcmp("integral", argv[1]) == 0.
So in your code...
#include <stdio.h>
#include <string.h>
int main(int argc, char **argv)
{
if (argc < 2) // no arguments were passed
{
// do something
}
if (strcmp("integral", argv[1]) == 0)
{
runIntegral(...); //or something
}
else
{
// do something else.
}
}
Better command line parsing
Of course, this was all very rudimentary, and as your program gets more complex, you'll likely want more advanced command line handling. For that, you could use a library like GNU getopt.
#include <stdio.h>
#include <stdlib.h>
int main(int argc, char **argv) {
int i, parameter = 0;
if (argc >= 2) {
/* there is 1 parameter (or more) in the command line used */
/* argv[0] may point to the program name */
/* argv[1] points to the 1st parameter */
/* argv[argc] is NULL */
parameter = atoi(argv[1]); /* better to use strtol */
if (parameter > 0) {
for (i = 0; i < parameter; i++) printf("%d ", i);
} else {
fprintf(stderr, "Please use a positive integer.\n");
}
}
return 0;
}
Parsing command line arguments in a primitive way as explained in the above answers is reasonable as long as the number of parameters that you need to deal with is not too much.
I strongly suggest you to use an industrial strength library for handling the command line arguments.
This will make your code more professional.
Such a library for C++ is available in the following website. I have used this library in many of my projects, hence I can confidently say that this one of the easiest yet useful library for command line argument parsing. Besides, since it is just a template library, it is easier to import into your project.
http://tclap.sourceforge.net/
A similar library is available for C as well.
http://argtable.sourceforge.net/
There's also a C standard built-in library to get command line arguments: getopt
You can check it on Wikipedia or in Argument-parsing helpers for C/Unix.