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24.\" $Id: elf_open.3 3643 2018-10-14 21:09:24Z jkoshy $
25.\"
26.Dd May 31, 2012
27.Dt ELF_OPEN 3
28.Os
29.Sh NAME
30.Nm elf_open
31.Nd open ELF objects and ar(1) archives
32.Sh LIBRARY
33.Lb libelf
34.Sh SYNOPSIS
35.In libelf.h
36.Ft "Elf *"
37.Fn elf_open "int fd"
38.Ft "Elf *"
39.Fn elf_openmemory "char *image" "size_t sz"
40.Sh DESCRIPTION
41.Em Important :
42The functions
43.Fn elf_open
44and
45.Fn elf_openmemory
46are extensions to the ELF(3) API, for the internal use of the
47Elftoolchain project.
48Portable applications should not use these functions.
49.Pp
50The function
51.Fn elf_open
52returns an Elf descriptor opened with mode
53.Dv ELF_C_READ
54for the ELF object or
55.Xr ar 1
56archive referenced by the file descriptor in argument
57.Ar fd .
58.Pp
59The function
60.Fn elf_openmemory
61returns an ELF descriptor opened with mode
62.Dv ELF_C_READ
63for the ELF object or
64.Xr ar 1
65archive contained in the memory area pointed to by the argument
66.Ar image .
67The argument
68.Ar sz
69specifies the size of the memory area in bytes.
70.Sh RETURN VALUES
71The function returns a pointer to a ELF descriptor if successful, or
72NULL if an error occurred.
73.Sh COMPATIBILITY
74These functions are non-standard extensions to the ELF(3) API set.
75.Pp
76The behavior of these functions differs from their counterparts
77.Xr elf_begin 3
78and
79.Xr elf_memory 3
80in that these functions will successfully open malformed ELF objects
81and
82.Xr ar 1
83archives, returning an Elf descriptor of type
84.Dv ELF_K_NONE .
85.Sh ERRORS
86These functions can fail with the following errors:
87.Bl -tag -width "[ELF_E_RESOURCE]"
88.It Bq Er ELF_E_ARGUMENT
89The argument
90.Ar fd
91was of an unsupported file type.
92.It Bq Er ELF_E_ARGUMENT
93The argument
94.Ar sz
95was zero, or the argument
96.Ar image
97was NULL.
98.It Bq Er ELF_E_IO
99The file descriptor in argument
100.Ar fd
101was invalid.
102.It Bq Er ELF_E_IO
103The file descriptor in argument
104.Ar fd
105could not be read.
106.It Bq Er ELF_E_RESOURCE
107An out of memory condition was encountered.
108.It Bq Er ELF_E_SEQUENCE
109Functions
110.Fn elf_open
111or
112.Fn elf_openmemory
113was called before a working version was established with
114.Xr elf_version 3 .
115.El
116.Sh SEE ALSO
117.Xr elf 3 ,
118.Xr elf_begin 3 ,
119.Xr elf_errno 3 ,
120.Xr elf_memory 3 ,
121.Xr gelf 3
122