The sprintf() function is just like printf(), except that the output is sent to buffer. The return value is the number of characters written

example:

char string[50];
int file_number = 0;

sprintf( string, "file.%d", file_number );
file_number++;
output_file = fopen( string, "w" );
Note that sprintf() does the opposite of a function like atoi() -- where atoi() converts a string into a number, sprintf() can be used to convert a number into a string.

For example, the following code uses sprintf() to convert an integer into a string of characters:

char result[100];
int num = 24;
sprintf( result, "%d", num );

This code is similar, except that it converts a floating-point number into an array of characters:

char result[100];
float fnum = 3.14159;
sprintf( result, "%f", fnum );