2.14 gvcvt, gcvtf—format double or float as string

Synopsis

     #include <stdlib.h>
     
     char *gcvt(double val, int precision, char *buf);
     char *gcvtf(float val, int precision, char *buf);
     

Description
gcvt writes a fully formatted number as a null-terminated string in the buffer *buf. gdvtf produces corresponding character representations of float numbers.

gcvt uses the same rules as the printf format `%.precisiong'—only negative values are signed (with `-'), and either exponential or ordinary decimal-fraction format is chosen depending on the number of significant digits (specified by precision).

Returns
The result is a pointer to the formatted representation of val (the same as the argument buf).

Portability
Neither function is ANSI C.

Supporting OS subroutines required: close, fstat, isatty, lseek, read, sbrk, write.