Posted By: Zheka
FILE *p as a global var; fflush() in lite-c - 02/16/18 12:46
Hello,
There are several things which I cannot get to work (Zorro).
Consider the following code;
Questions:
1. If I skip closing the file in main() and re-opening it in run(), the result of printf() is 0.
Since *p is defined globally, I would expect it to keep its value, and then be able to read from the file p, still seemingly open.
Why doesn't that work?
2. to implement (1), If I do fflush(p) in main() instead of fclose(), I can see that the data are not physically written to a file (as would be expected).
Are there any nuances to it?
Thank you in advance for help.
There are several things which I cannot get to work (Zorro).
Consider the following code;
Quote:
FILE *p;
main ()
{
int tmp=3;
p=fopen("d:\myfile.csv",w+b);
fwrite(&tmp,sizeof(int),1,p);
fclose(p);
}
run()
{
int tmp;
p=fopen("d:\myfile.csv",rb);
fread(&tmp,sizeof(int),1,p);
printf(" n PB=%i", tmp);
fclose(p);
}
main ()
{
int tmp=3;
p=fopen("d:\myfile.csv",w+b);
fwrite(&tmp,sizeof(int),1,p);
fclose(p);
}
run()
{
int tmp;
p=fopen("d:\myfile.csv",rb);
fread(&tmp,sizeof(int),1,p);
printf(" n PB=%i", tmp);
fclose(p);
}
Questions:
1. If I skip closing the file in main() and re-opening it in run(), the result of printf() is 0.
Since *p is defined globally, I would expect it to keep its value, and then be able to read from the file p, still seemingly open.
Why doesn't that work?
2. to implement (1), If I do fflush(p) in main() instead of fclose(), I can see that the data are not physically written to a file (as would be expected).
Are there any nuances to it?
Thank you in advance for help.