printf
A format specifier follows this prototype:
%[flags][width][.precision][length]specifier
Where the specifier character at the end is the most significant component, since it defines the type and the interpretation of its corresponding argument:
| specifier | Output | Example |
|---|---|---|
| d or i | Signed decimal integer | 392 |
| u | Unsigned decimal integer | 7235 |
| o | Unsigned octal | 610 |
| x | Unsigned hexadecimal integer | 7fa |
| X | Unsigned hexadecimal integer (uppercase) | 7FA |
| f | Decimal floating point, lowercase | 392.65 |
| F | Decimal floating point, uppercase | 392.65 |
| e | Scientific notation (mantissa/exponent), lowercase | 3.9265e+2 |
| E | Scientific notation (mantissa/exponent), uppercase | 3.9265E+2 |
| g | Use the shortest representation: %e or %f | 392.65 |
| G | Use the shortest representation: %E or %F | 392.65 |
| a | Hexadecimal floating point, lowercase | -0xc.90fep-2 |
| A | Hexadecimal floating point, uppercase | -0XC.90FEP-2 |
| c | Character | a |
| s | String of characters | sample |
| p | Pointer address | b8000000 |
| n | Nothing printed. The corresponding argument must be a pointer to a signed int. The number of characters written so far is stored in the pointed location. | |
| % | A % followed by another % character will write a single % to the stream. | % |
Return Value
On success, the total number of characters written is returned.
If a writing error occurs, theerror indicator(ferror) is set and a negative number is returned.
If a multibyte character encoding error occurs while writing wide characters, errno is set toEILSEQand a negative number is returned.