fopen / fopen_s and writing to files
- by yCalleecharan
Hi,
I'm using fopen in C to write the output to a text file. The function declaration is (where ARRAY_SIZE has been defined earlier):
void create_out_file(char file_name[],long double *z1){
FILE *out;
int i;
if((out = fopen(file_name, "w+")) == NULL){
fprintf(stderr, "* Open error on output file %s", file_name);
exit(-1);
}
for(i = 0; i < ARRAY_SIZE; i++)
fprintf(out, "%.16Le\n", z1[i]);
fclose(out);
}
My questions:
On compilation with MVS2008 I get the warning: warning C4996: 'fopen': This function or variable may be unsafe. Consider using fopen_s instead. I haven't see much information on fopen_s so that I can change my code. Any suggestions?
Can one instruct fprintf to write at desired precision? If I'm using long double then I assume that my answers are good till 15 digits after the decimal point. Am I right?
Thanks a lot...