.TH GELF_NEWEHDR 3 2025-09-17 "Libelf" "Libelf Programmer's Manual"

.SH NAME
gelf_newehdr \- allocate and initialize a new ELF file header

.SH SYNOPSIS
.nf
.B #include <gelf.h>

.BI "void *gelf_newehdr(Elf *" elf ", int " class ");"
.fi

.SH DESCRIPTION
.BR gelf_newehdr ()
allocates and initializes a new ELF header for
.IR elf ,
if a header does not already exist.  When a new ELF header is created,
all of its fields are zero-initialized.

.PP
The caller must specify the ELF class via
.IR class ,
which must be either:
.TP
.B ELFCLASS32
Request a 32\-bit ELF file header.
.TP
.B ELFCLASS64
Request a 64\-bit ELF file header.

.SH PARAMETERS
.TP
.I elf
Pointer to an ELF descriptor of kind
.BR ELF_K_ELF .

.TP
.I class
The requested ELF class for the new header. Must be
.B ELFCLASS32
or
.BR ELFCLASS64 .

.SH RETURN VALUE
On success,
.BR gelf_newehdr ()
will return a non-zero value.  The ELF header of
.I elf
can be retrieved using
.BR gelf_getehdr ().
.BR elf32_getehdr ()
or
.BR elf64_getehdr ()
can also be used depending on the ELF class specified by
.IR class .

On failure, NULL is returned and elf_errno is set.  If
.I elf
is NULL then NULL is returned without setting elf_errno.

In other libelf implementations the
.BR gelf_newehdr ()
return value may be a different type.

.SH SEE ALSO
.BR elf32_getehdr ()
.BR elf64_getehdr ()
.BR gelf_getehdr (3),
.BR gelf_update_ehdr (3),
.BR libelf (3),
.BR elf (5)

.SH ATTRIBUTES
.TS
allbox;
lbx lb lb
l l l.
Interface	Attribute	Value
T{
.na
.nh
.BR gelf_newehdr ()
T}	Thread safety	MT-Safe
.TE

.SH REPORTING BUGS
Report bugs to <elfutils-devel@sourceware.org> or https://sourceware.org/bugzilla/.