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Conversion functions for double arguments.
Note that these functions are not located in the default library, libc.a, but in the mathematical library, libm.a. So when linking the application, the -lm option needs to be specified.

Code:
 
#define  DTOSTR_ALWAYS_SIGN   0x01 
#define  DTOSTR_PLUS_SIGN   0x02 
#define  DTOSTR_UPPERCASE   0x04 
char *  dtostre (double __val, char *__s, unsigned char __prec, unsigned char __flags) 
char *  dtostrf (double __val, char __width, char __prec, char *__s)