2.14 gcvt, 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. gcvtf 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.