This appendix summarizes all the format specifications you have available for stream input and output. You use these with the standard streams
stdin, stdout, and
stderr, as well as text file streams.
There are three standard library functions for formatted output: the
printf() that writes to the standard output stream
stdout (which by default is the command line), the
sprintf() function that writes to a string, and the
fprintf() function that writes to a file. These functions have the following form:
int printf(const char* format_string, . . .); int sprintf(char* source_string, const char* format_string, . . .); int fprintf(FILE* file_stream, const char* format_string, ...