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$FreeBSD$
.Dd October 22, 2007 .Dt ELF_GETSCN 3 .Os .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 n 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.
p 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.
p Function .Fn elf_ndxscn returns the section table index associated with section descriptor .Ar scn .
p 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 .
p 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.
p 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: l -tag -width "[ELF_E_RESOURCE]" t Bq Er ELF_E_ARGUMENT Arguments .Ar elf or .Ar scn were NULL. t Bq Er ELF_E_ARGUMENT Argument .Ar index exceeded the current number of sections in the ELF object. t Bq Er ELF_E_ARGUMENT Argument .Ar elf was not a descriptor for an ELF file. t Bq Er ELF_E_ARGUMENT Section descriptor .Ar scn was not associated with ELF descriptor .Ar elf . t Bq Er ELF_E_CLASS Descriptor .Ar elf was of an unknown ELF class. t 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