'\" 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 2024-05-02 "Linux man-pages 6.9.1" .SH NAME gcvt \- convert a floating-point number to a string .SH LIBRARY Standard C library .RI ( libc ", " \-lc ) .SH SYNOPSIS .nf .B #include .P .BI "char *gcvt(double " number ", int " ndigit ", char *" buf ); .fi .P .RS -4 Feature Test Macro Requirements for glibc (see .BR feature_test_macros (7)): .RE .P .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). .TS allbox; lbx lb lb l l l. Interface Attribute Value T{ .na .nh .BR gcvt () T} Thread safety MT-Safe .TE .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)