---
name: "qecvt"
section: "3"
platform: "linux"
package: "man-pages"
version: "6.19-1"
release: "Arch Linux 2026-11-01"
platforms: ["linux"]
url: "https://new.carta.tech/qecvt"
---

# qecvt(3)

convert a floating-point number to a string

## NAME

qecvt, qfcvt, qgcvt - convert a floating-point number to a string

## LIBRARY

Standard C library (*libc*, *-lc*)

## SYNOPSIS

```
#include <stdlib.h>
```

**\[\[deprecated\]\] char \*qecvt(long double** *number***, int** *ndigits***,**                            **int \*restrict** *decpt***, int \*restrict** *sign***);** **\[\[deprecated\]\] char \*qfcvt(long double** *number***, int** *ndigits***,**                            **int \*restrict** *decpt***, int \*restrict** *sign***);** **\[\[deprecated\]\] char \*qgcvt(long double** *number***, int** *ndigit***, char \****buf***);**

Feature Test Macro Requirements for glibc (see [**feature\_test\_macros**(7)](/feature_test_macros/7.md)):

**qecvt**(), **qfcvt**(), **qgcvt**():

```
    Since glibc 2.19:
        _DEFAULT_SOURCE
    In glibc up to and including 2.19:
        _SVID_SOURCE
```

## DESCRIPTION

The functions **qecvt**(), **qfcvt**(), and **qgcvt**() are identical to [**ecvt**(3)](/ecvt/3.md), [**fcvt**(3)](/fcvt/3.md), and [**gcvt**(3)](/gcvt/3.md) respectively, except that they use a *long double* argument *number*. See [**ecvt**(3)](/ecvt/3.md) and [**gcvt**(3)](/gcvt/3.md).

## ATTRIBUTES

For an explanation of the terms used in this section, see [**attributes**(7)](/attributes/7.md).

| | | |
| --- | --- | --- |
| **Interface** | **Attribute** | **Value** |
| **qecvt**() | Thread safety | MT-Unsafe race:qecvt |
| **qfcvt**() | Thread safety | MT-Unsafe race:qfcvt |
| **qgcvt**() | Thread safety | MT-Safe |

## STANDARDS

None.

## HISTORY

SVr4, SunOS, GNU.

These functions are obsolete. Instead, [**snprintf**(3)](/snprintf/3.md) is recommended.

## SEE ALSO

[**ecvt**(3)](/ecvt/3.md), [**ecvt\_r**(3)](/ecvt_r/3.md), [**gcvt**(3)](/gcvt/3.md), [**sprintf**(3)](/sprintf/3.md)