--- name: "gd_alter_endianness" section: "3" platform: "linux" package: "libgetdata-doc" version: "0.11.0-15" release: "Debian 13 (Trixie)" platforms: ["linux"] url: "https://new.carta.tech/gd_alter_endianness" --- # gd\_alter\_endianness(3) modify the byte sex of fields in a Dirfile ## NAME gd\_alter\_endianness — modify the byte sex of fields in a Dirfile ## SYNOPSIS **#include \** **int gd\_alter\_endianness(DIRFILE \****dirfile***, unsigned long** *byte\_sex***, int** *fragment\_index***, int** *recode***);** ## DESCRIPTION The **gd\_alter\_endianness**() function sets the byte sex of the format specification fragment given by *fragment\_index* to *byte\_sex* in the [dirfile(5)](/dirfile/5.md) database specified by *dirfile*. The byte sex of a fragment indicate the endianness of data stored in binary files associated with **RAW** fields defined in the specified fragment. The byte sex of a fragment containing no **RAW** fields is ignored. The *byte\_sex* argument should be one of the following:\ .TP 8 **0 (zero)** Indicating that the byte sex should be the native endianness of the host, whichever that may be.\ .TP 8 **GD\_BIG\_ENDIAN** Indicating that the byte sex should be big endian.\ .TP 8 **GD\_LITTLE\_ENDIAN** Indicating that the byte sex should be little endian. - (**GD\_BIG\_ENDIAN** \| **GD\_LITTLE\_ENDIAN**) Indicating that the byte sex should be the opposite of the native endianness of the host, whichever that may be. Furthermore, any of these may be bitwise or'd with **GD\_ARM\_ENDIAN** or **GD\_NOT\_ARM\_ENDIAN** indicating that the floating point data are stored in the ARM middle-endian format. In addition to being simply a valid fragment index, *fragment\_index* may also be the special value **GD\_ALL\_FRAGMENTS**, which indicates that the byte sex of all fragments in the database should be changed. If the *recode* argument is non-zero, this call will byte swap the binary data of affected **RAW** fields to account for the change in byte sex. If the encoding of the fragment is endianness insensitive, or if the data type is only one byte in size, no change is made. The I/O pointer of all affected **RAW** fields is reset to the beginning-of-frame. If *recode* is zero, affected binary files are left untouched. ## RETURN VALUE Upon successful completion, **gd\_alter\_endianness**() returns zero. On error, it returns a negative-valued error code. Possible error codes are:\ .TP 8 **GD\_E\_ACCMODE** The specified dirfile was opened read-only.\ .TP 8 **GD\_E\_ALLOC** The library was unable to allocate memory.\ .TP 8 **GD\_E\_ARGUMENT** The supplied *byte\_sex* was invalid.\ .TP 8 **GD\_E\_BAD\_DIRFILE** The supplied dirfile was invalid.\ .TP 8 **GD\_E\_BAD\_INDEX** The supplied index was out of range.\ .TP 8 **GD\_E\_IO** An I/O error occurred while attempting to byte swap a binary file.\ .TP 8 **GD\_E\_PROTECTED** The metadata of the indicated format specification fragment was protected from change, or the binary data of the fragment was protected from change and binary file byte swapping was requested.\ .TP 8 **GD\_E\_UNCLEAN\_DB** An error occurred while moving the byte-swapped file into place. As a result, the database may be in an unclean state. See the **NOTES** section below for recovery instructions. In this case, the dirfile will be flagged as invalid, to prevent further database corruption. It should be immediately closed.\ .TP 8 **GD\_E\_UNKNOWN\_ENCODING** The encoding scheme of the fragment is unknown.\ .TP 8 **GD\_E\_UNSUPPORTED** The encoding scheme of the fragment does not support binary file byte swapping. 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). ## NOTES A binary file byte swap occurs out-of-place. As a result, sufficient space must be present on the filesystem for the binary files of all **RAW** fields in the fragment both before and after translation. If all fragments are updated by specifying **GD\_ALL\_FRAGMENTS**, the byte swapping occurs one fragment at a time. An error code of **GD\_E\_UNCLEAN\_DB** indicates a system error occurred while moving the byte-swapped binary data into place or when deleting the old data. If this happens, the database may be left in an unclean state. The caller should check the filesystem directly to ascertain the state of the dirfile data before continuing. For recovery instructions, see the file /usr/share/doc/getdata/unclean\_database\_recovery.txt. ## HISTORY The function **dirfile\_alter\_endianness**() appeared in GetData-0.5.0. In GetData-0.7.0, this function was renamed to **gd\_alter\_endianness**(). The **GD\_E\_ARM\_ENDIAN** and **GD\_NOT\_ARM\_ENDIAN** flags also appeared in this version. in GetData-0.10.0, the error return from this function changed from -1 to a negative-valued error code. ## SEE ALSO [**gd\_open**(3)](/gd_open/3.md), [**gd\_error**(3)](/gd_error/3.md), [**gd\_error\_string**(3)](/gd_error_string/3.md), [**gd\_endianness**(3)](/gd_endianness/3.md), [dirfile(5)](/dirfile/5.md), [dirfile-format(5)](/dirfile-format/5.md)