I'm trying to make a program to open a file, called "write.txt".
#include <stdio.h>
main() {
FILE *fp;
fp = fopen("write.txt", "w");
return 0;
}
Should this work? Because it returns nothing.
Other than an old variant of main
, there's not really much wrong with that code. It should, barring errors, create the file.
However, since you're not checking the return value from fopen
, you may get an error of some sort and not know about it.
I'd start with:
#include <stdio.h>
#include <errno.h>
int main (void) {
FILE *fp;
fp = fopen ("write.txt","w");
if (fp == NULL) {
printf ("File not created okay, errno = %d\n", errno);
return 1;
}
//fprintf (fp, "Hello, there.\n"); // if you want something in the file.
fclose (fp);
printf ("File created okay\n");
return 0;
}
If you're adamant that the file isn't being created but the above code says it is, then you may be a victim of the dreaded "IDE is working in a different directory from what you think" syndrome :-)
Some IDEs (such as Visual Studio) will actually run your code while they're in a directory like <solution-name>\bin
or <solution-name>\debug
. You can find out by putting:
system ("cd"); // for Windows
system ("pwd") // for UNIXy systems
in to your code to see where it's running. That's where a file will be created if you specify a relative path line "write.txt"
. Otherwise, you can specify an absolute path to ensure it tries to create it at a specific point in the file system.