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.\" $Id: gelf_newphdr.3,v 1.3 2020/05/18 06:46:23 jsg Exp $
.\"
.Dd June 12, 2019
.Dt GELF_NEWPHDR 3
.Os
.Sh NAME
.Nm elf32_newphdr ,
.Nm elf64_newphdr ,
.Nm gelf_newphdr
.Nd allocate an ELF program header table
.Sh LIBRARY
.Lb libelf
.Sh SYNOPSIS
.In libelf.h
.Ft "Elf32_Phdr *"
.Fn elf32_newphdr "Elf *elf" "size_t count"
.Ft "Elf64_Phdr *"
.Fn elf64_newphdr "Elf *elf" "size_t count"
.In gelf.h
.Ft "void *"
.Fn gelf_newphdr "Elf *elf" "size_t count"
.Sh DESCRIPTION
These functions allocate an ELF Program Header table
for an ELF descriptor.
.Vt Elf32_Phdr
and
.Vt Elf64_Phdr
descriptors are described further in
.Xr elf 5 .
.Pp
Functions
.Fn elf32_newphdr
and
.Fn elf64_newphdr
allocate a table of
.Ar count
.Vt Elf32_Phdr
and
.Vt Elf64_Phdr
descriptors respectively,
discarding any existing program header table
already present in the ELF descriptor
.Ar elf .
A value of zero for argument
.Ar count
may be used to delete an existing program header table
from an ELF descriptor.
.Pp
Function
.Fn gelf_newphdr
will return a table of
.Vt Elf32_Phdr
or
.Vt Elf64_Phdr
with
.Ar count
elements depending on the ELF class of ELF descriptor
.Ar elf .
.Pp
The functions set the
.Dv ELF_F_DIRTY
flag on the program header table.
All members of the returned array of Phdr structures
will be initialized to zero.
.Pp
After a successful call to these functions, the pointer returned
by a prior call to
.Fn elf32_getphdr
or
.Fn elf64_getphdr
on the same descriptor
.Ar elf
will no longer be valid.
.Sh RETURN VALUES
The functions a valid pointer if successful, or NULL in case an error
was encountered.
.Sh COMPATIBILITY
The
.Fn gelf_newphdr
function uses a type of
.Ft "void *"
for its returned value.
This differs from some other implementations of the
.Xr elf 3
API, which use an
.Ft "unsigned long"
return type.
.Sh ERRORS
These functions may fail with the following errors:
.Bl -tag -width "[ELF_E_RESOURCE]"
.It Bq Er ELF_E_ARGUMENT
Argument
.Ar elf
was NULL.
.It Bq Er ELF_E_ARGUMENT
Argument
.Ar elf
was not a descriptor for an ELF object.
.It Bq Er ELF_E_CLASS
ELF descriptor
.Ar elf
was of an unrecognized class.
.It Bq Er ELF_E_RESOURCE
An out of memory condition was detected.
.It Bq Er ELF_E_SEQUENCE
An executable header was not allocated for ELF descriptor
.Ar elf
before using these APIs.
.El
.Sh SEE ALSO
.Xr elf 3 ,
.Xr elf32_getphdr 3 ,
.Xr elf32_newehdr 3 ,
.Xr elf64_getphdr 3 ,
.Xr elf64_newehdr 3 ,
.Xr elf_flagphdr 3 ,
.Xr elf_getphnum 3 ,
.Xr gelf 3 ,
.Xr gelf_getphdr 3 ,
.Xr gelf_newehdr 3 ,
.Xr elf 5