.\" $NetBSD: elf_getscn.3,v 1.1.1.1 2009/12/19 05:43:39 thorpej Exp $ .\" .\" Copyright (c) 2006,2007 Joseph Koshy. All rights reserved. .\" .\" Redistribution and use in source and binary forms, with or without .\" modification, are permitted provided that the following conditions .\" are met: .\" 1. Redistributions of source code must retain the above copyright .\" notice, this list of conditions and the following disclaimer. .\" 2. Redistributions in binary form must reproduce the above copyright .\" notice, this list of conditions and the following disclaimer in the .\" documentation and/or other materials provided with the distribution. .\" .\" This software is provided by Joseph Koshy ``as is'' and .\" any express or implied warranties, including, but not limited to, the .\" implied warranties of merchantability and fitness for a particular purpose .\" are disclaimed. in no event shall Joseph Koshy be liable .\" for any direct, indirect, incidental, special, exemplary, or consequential .\" damages (including, but not limited to, procurement of substitute goods .\" or services; loss of use, data, or profits; or business interruption) .\" however caused and on any theory of liability, whether in contract, strict .\" liability, or tort (including negligence or otherwise) arising in any way .\" out of the use of this software, even if advised of the possibility of .\" such damage. .\" .\" $FreeBSD: src/lib/libelf/elf_getscn.3,v 1.3.2.1.2.1 2009/10/25 01:10:29 kensmith Exp $ .\" .Dd October 22, 2007 .Os .Dt ELF_GETSCN 3 .Sh NAME .Nm elf_getscn , .Nm elf_ndxscn , .Nm elf_newscn , .Nm elf_nextscn .Nd get/allocate section information for an ELF object .Sh LIBRARY .Lb libelf .Sh SYNOPSIS .In libelf.h .Ft "Elf_Scn *" .Fn elf_getscn "Elf *elf" "size_t index" .Ft size_t .Fn elf_ndxscn "Elf_Scn *scn" .Ft "Elf_Scn *" .Fn elf_newscn "Elf *elf" .Ft "Elf_Scn *" .Fn elf_nextscn "Elf *elf" "Elf_Scn *scn" .Sh DESCRIPTION These functions are used to iterate through the sections associated with an ELF descriptor. .Pp Function .Fn elf_getscn will return a section descriptor for the section at index .Ar index in the object denoted by ELF descriptor .Ar elf . An error will be signalled if the specified section does not exist. .Pp Function .Fn elf_ndxscn returns the section table index associated with section descriptor .Ar scn . .Pp Function .Fn elf_newscn creates a new section and appends it to the list of sections associated with descriptor .Ar elf . The library will automatically increment the .Va e_shnum field of the ELF header associated with descriptor .Ar elf , and will set the .Dv ELF_F_DIRTY flag on the returned section descriptor. For ELF descriptors opened for writing, the ELF library will automatically create an empty section at index zero .Dv ( SHN_UNDEF ) on the first call to .Fn elf_newscn . .Pp Function .Fn elf_nextscn takes a section descriptor .Ar scn and returns a pointer to the section descriptor at the next higher index. Argument .Ar scn is allowed to be NULL, in which case this function will return a pointer to the section descriptor at index 1. If no further sections are present, function .Fn elf_nextscn will return a NULL pointer. .Sh RETURN VALUES Functions .Fn elf_getscn , .Fn elf_newscn and .Fn elf_nextscn return a valid pointer to a section descriptor if successful, or NULL if an error occurs. .Pp Function .Fn elf_ndxscn returns a valid section table index if successful, or .Dv SHN_UNDEF if an error occurs. .Sh ERRORS These functions may fail with the following errors: .Bl -tag -width "[ELF_E_RESOURCE]" .It Bq Er ELF_E_ARGUMENT Arguments .Ar elf or .Ar scn were NULL. .It Bq Er ELF_E_ARGUMENT Argument .Ar index exceeded the current number of sections in the ELF object. .It Bq Er ELF_E_ARGUMENT Argument .Ar elf was not a descriptor for an ELF file. .It Bq Er ELF_E_ARGUMENT Section descriptor .Ar scn was not associated with ELF descriptor .Ar elf . .It Bq Er ELF_E_CLASS Descriptor .Ar elf was of an unknown ELF class. .It Bq Er ELF_E_SECTION Argument .Ar elf specified extended section numbering in the ELF header with the section header at index .Dv SHN_UNDEF not being of type .Dv SHT_NULL . .El .Sh SEE ALSO .Xr elf 3 , .Xr elf_flagdata 3 , .Xr elf_flagscn 3 , .Xr elf_getdata 3 , .Xr elf_getshdr 3 , .Xr gelf 3