'\" t
.\" Copyright 1993 David Metcalfe (david@prism.demon.co.uk)
.\"
.\" SPDX-License-Identifier: Linux-man-pages-copyleft
.\"
.\" References consulted:
.\"     Linux libc source code
.\"     Lewine's _POSIX Programmer's Guide_ (O'Reilly & Associates, 1991)
.\"     386BSD man pages
.\" Modified Sat Jul 24 19:32:25 1993 by Rik Faith (faith@cs.unc.edu)
.TH gcvt 3 2023-03-30 "Linux man-pages 6.04"
.SH NAME
gcvt \- convert a floating-point number to a string
.SH LIBRARY
Standard C library
.RI ( libc ", " \-lc )
.SH SYNOPSIS
.nf
.B #include <stdlib.h>
.PP
.BI "char *gcvt(double " number ", int " ndigit ", char *" buf );
.fi
.PP
.RS -4
Feature Test Macro Requirements for glibc (see
.BR feature_test_macros (7)):
.RE
.PP
.BR gcvt ():
.nf
    Since glibc 2.17
        (_XOPEN_SOURCE >= 500 && ! (_POSIX_C_SOURCE >= 200809L))
            || /* glibc >= 2.20 */ _DEFAULT_SOURCE
            || /* glibc <= 2.19 */ _SVID_SOURCE
    glibc 2.12 to glibc 2.16:
        (_XOPEN_SOURCE >= 500 && ! (_POSIX_C_SOURCE >= 200112L))
            || _SVID_SOURCE
    Before glibc 2.12:
        _SVID_SOURCE || _XOPEN_SOURCE >= 500
.\"        || _XOPEN_SOURCE && _XOPEN_SOURCE_EXTENDED
.fi
.SH DESCRIPTION
The
.BR gcvt ()
function converts \fInumber\fP to a minimal length null-terminated
ASCII string and stores the result in \fIbuf\fP.
It produces \fIndigit\fP significant digits in either
.BR printf (3)
F format or E format.
.SH RETURN VALUE
The
.BR gcvt ()
function returns
\fIbuf\fP.
.SH ATTRIBUTES
For an explanation of the terms used in this section, see
.BR attributes (7).
.ad l
.nh
.TS
allbox;
lbx lb lb
l l l.
Interface	Attribute	Value
T{
.BR gcvt ()
T}	Thread safety	MT-Safe
.TE
.hy
.ad
.sp 1
.SH STANDARDS
None.
.SH HISTORY
Marked as LEGACY in POSIX.1-2001.
POSIX.1-2008 removed it,
recommending the use of
.BR sprintf (3)
instead (though
.BR snprintf (3)
may be preferable).
.SH SEE ALSO
.BR ecvt (3),
.BR fcvt (3),
.BR sprintf (3)