---
name: "gd_frameoffset"
section: "3"
platform: "linux"
package: "libgetdata-doc"
version: "0.11.0-15"
release: "Debian 13 (Trixie)"
platforms: ["linux"]
url: "https://new.carta.tech/gd_frameoffset"
---

# gd\_frameoffset(3)

report the starting frame of fields in a Dirfile

## NAME

gd\_frameoffset — report the starting frame of fields in a Dirfile

## SYNOPSIS

**#include \<getdata.h\>**

**off\_t gd\_frameoffset(DIRFILE \****dirfile***, int** *fragment\_index***);**

## DESCRIPTION

The **gd\_frameoffset**() function queries a [dirfile(5)](/dirfile/5.md) database specified by *dirfile* and returns the frame offset (see [dirfile-format(5)](/dirfile-format/5.md)) for the fragment indexed by *fragment\_index*. The frame offset of a fragment indicate the frame number of the first sample of data stored in binary files associated with **RAW** fields defined in the specified fragment.  The frame offset of a fragment containing no **RAW** fields is ignored.

The *dirfile* argument must point to a valid DIRFILE object previously created by a call to [**gd\_open**(3)](/gd_open/3.md).

## RETURN VALUE

Upon successful completion, **gd\_frameoffset**() returns a non-negative integer containing the frame offset of the specified fragment.  On error, it returns a negative-valued error code.  Possible error codes are:\
  .TP 8 **GD\_E\_BAD\_DIRFILE** The supplied dirfile was invalid.\
  .TP 8 **GD\_E\_BAD\_INDEX** The supplied index was out of range.

The error code is also stored in the **DIRFILE** object and may be retrieved after this function returns by calling [**gd\_error**(3)](/gd_error/3.md). A descriptive error string for the error may be obtained by calling [**gd\_error\_string**(3)](/gd_error_string/3.md).

## HISTORY

The **get\_frameoffset**() function appeared in GetData-0.5.0.

In GetData-0.7.0, this function was renamed to **gd\_frameoffset**().

In GetData-0.10.0, the error return from this function changed from -1 to a negative-valued error code.

## SEE ALSO

[**gd\_alter\_frameoffset**(3)](/gd_alter_frameoffset/3.md), [**gd\_error**(3)](/gd_error/3.md), [**gd\_error\_string**(3)](/gd_error_string/3.md), [**gd\_open**(3)](/gd_open/3.md), [dirfile(5)](/dirfile/5.md), [dirfile-format(5)](/dirfile-format/5.md)