.\" header.tmac. GetData manual macros. .\" .\" Copyright (C) 2016 D. V. Wiebe .\" .\"""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""" .\" .\" This file is part of the GetData project. .\" .\" Permission is granted to copy, distribute and/or modify this document .\" under the terms of the GNU Free Documentation License, Version 1.2 or .\" any later version published by the Free Software Foundation; with no .\" Invariant Sections, with no Front-Cover Texts, and with no Back-Cover .\" Texts. A copy of the license is included in the `COPYING.DOC' file .\" as part of this distribution. .\" Format a function name with optional trailer: func_name()trailer .de FN \" func_name [trailer] .nh .BR \\$1 ()\\$2 .hy .. .\" Format a reference to section 3 of the manual: name(3)trailer .de F3 \" func_name [trailer] .nh .BR \\$1 (3)\\$2 .hy .. .\" Format the header of a list of definitons .de DD \" name alt... .ie "\\$2"" \{ \ .TP 8 .PD .B \\$1 \} .el \{ \ .PP .B \\$1 .PD 0 .DD \\$2 \\$3 \} .. .\" Start a code block: Note: groff defines an undocumented .SC for .\" Bell Labs man legacy reasons. .de SC .fam C .na .nh .. .\" End a code block .de EC .hy .ad .fam .. .\" Format a structure pointer member: struct->member\fRtrailer .de SPM \" struct member trailer .nh .ie "\\$3"" .IB \\$1 ->\: \\$2 .el .IB \\$1 ->\: \\$2\fR\\$3 .hy .. .\" Format a function argument .de ARG \" name trailer .nh .ie "\\$2"" .I \\$1 .el .IR \\$1 \\$2 .hy .. .\" Hyphenation exceptions .hw sarray carray lincom linterp .\" gd_alter_endianness.3. The gd_alter_endianness man page. .\" .\" man/gd_alter_endianness.3in. Generated from gd_alter_endianness.3in.in by configure. .\" .\" Copyright (C) 2008, 2010, 2012, 2014, 2016 D. V. Wiebe .\" .\"""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""" .\" .\" This file is part of the GetData project. .\" .\" Permission is granted to copy, distribute and/or modify this document .\" under the terms of the GNU Free Documentation License, Version 1.2 or .\" any later version published by the Free Software Foundation; with no .\" Invariant Sections, with no Front-Cover Texts, and with no Back-Cover .\" Texts. A copy of the license is included in the `COPYING.DOC' file .\" as part of this distribution. .\" .TH gd_alter_endianness 3 "25 December 2016" "Version 0.10.0" "GETDATA" .SH NAME gd_alter_endianness \(em modify the byte sex of fields in a Dirfile .SH SYNOPSIS .SC .B #include .HP .BI "int gd_alter_endianness(DIRFILE *" dirfile ", unsigned long" .IB byte_sex ", int " fragment_index ", int " recode ); .EC .SH DESCRIPTION The .FN gd_alter_endianness function sets the byte sex of the format specification fragment given by .ARG fragment_index to .ARG byte_sex in the dirfile(5) database specified by .ARG dirfile . The byte sex of a fragment indicate the endianness of data stored in binary files associated with .B RAW fields defined in the specified fragment. The byte sex of a fragment containing no .B RAW fields is ignored. The .ARG byte_sex argument should be one of the following: .DD "0\fR (zero)" Indicating that the byte sex should be the native endianness of the host, whichever that may be. .DD GD_BIG_ENDIAN Indicating that the byte sex should be big endian. .DD GD_LITTLE_ENDIAN Indicating that the byte sex should be little endian. .TP .RB ( 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. .PP Furthermore, any of these may be bitwise or'd with .B GD_ARM_ENDIAN or .B GD_NOT_ARM_ENDIAN indicating that the floating point data are stored in the ARM middle-endian format. .PP In addition to being simply a valid fragment index, .ARG fragment_index may also be the special value .BR GD_ALL_FRAGMENTS , which indicates that the byte sex of all fragments in the database should be changed. If the .ARG recode argument is non-zero, this call will byte swap the binary data of affected .B 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 .B RAW fields is reset to the beginning-of-frame. If .ARG recode is zero, affected binary files are left untouched. .SH RETURN VALUE Upon successful completion, .FN gd_alter_endianness returns zero. On error, it returns a negative-valued error code. Possible error codes are: .DD GD_E_ACCMODE The specified dirfile was opened read-only. .DD GD_E_ALLOC The library was unable to allocate memory. .DD GD_E_ARGUMENT The supplied .ARG byte_sex was invalid. .DD GD_E_BAD_DIRFILE The supplied dirfile was invalid. .DD GD_E_BAD_INDEX The supplied index was out of range. .DD GD_E_IO An I/O error occurred while attempting to byte swap a binary file. .DD 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. .DD 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 .B 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. .DD GD_E_UNKNOWN_ENCODING The encoding scheme of the fragment is unknown. .DD GD_E_UNSUPPORTED The encoding scheme of the fragment does not support binary file byte swapping. .PP The error code is also stored in the .B DIRFILE object and may be retrieved after this function returns by calling .F3 gd_error . A descriptive error string for the error may be obtained by calling .F3 gd_error_string . .SH 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 .B RAW fields in the fragment both before and after translation. If all fragments are updated by specifying .BR GD_ALL_FRAGMENTS , the byte swapping occurs one fragment at a time. An error code of .B 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. .SH HISTORY The function .FN dirfile_alter_endianness appeared in GetData-0.5.0. In GetData-0.7.0, this function was renamed to .FN gd_alter_endianness . The .B GD_E_ARM_ENDIAN and .B 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. .SH SEE ALSO .F3 gd_open , .F3 gd_error , .F3 gd_error_string , .F3 gd_endianness , dirfile(5), dirfile-format(5)