The header file <stdio.h> defines a number of functions to format and output values. The format-control directives that for the formatted input and output function are described in Formatted input control strings and Formatted output control strings.

Character and string I/O functions
getchar Read a character from standard input
gets Read a string from standard input
putchar Write a character to standard output
puts Write a string to standard output
Formatted input functions
scanf Read formatted text from standard input
sscanf Read formatted text from a string
vscanf Read formatted text from standard input using a va_list argument
vsscanf Read formatted text from a string using a va_list argument
Formatted output functions
printf Write formatted text to standard output
snprintf Write formatted text to a string with truncation
sprintf Write formatted text to a string
vprintf Write formatted text to standard output using a va_list argument
vsnprintf Write formatted text to a string with truncation using a va_list argument
vsprintf Write formatted text to a string using a va_list argument