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24.\" $Id: elf_open.3 3743 2019-06-12 19:36:30Z jkoshy $
25.\"
26.Dd June 12, 2019
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
47.Xr elf 3
48API, for the internal use of the
49Elftoolchain project.
50Portable applications should not use these functions.
51.Pp
52The function
53.Fn elf_open
54returns an Elf descriptor opened with mode
55.Dv ELF_C_READ
56for the ELF object or
57.Xr ar 1
58archive referenced by the file descriptor in argument
59.Ar fd .
60.Pp
61The function
62.Fn elf_openmemory
63returns an ELF descriptor opened with mode
64.Dv ELF_C_READ
65for the ELF object or
66.Xr ar 1
67archive contained in the memory area pointed to by the argument
68.Ar image .
69The argument
70.Ar sz
71specifies the size of the memory area in bytes.
72.Sh RETURN VALUES
73The function returns a pointer to a ELF descriptor if successful, or
74NULL if an error occurred.
75.Sh COMPATIBILITY
76These functions are non-standard extensions to the
77.Xr elf 3
78API set.
79.Pp
80The behavior of these functions differs from their counterparts
81.Xr elf_begin 3
82and
83.Xr elf_memory 3
84in that these functions will successfully open malformed ELF objects
85and
86.Xr ar 1
87archives, returning an Elf descriptor of type
88.Dv ELF_K_NONE .
89.Sh ERRORS
90These functions can fail with the following errors:
91.Bl -tag -width "[ELF_E_RESOURCE]"
92.It Bq Er ELF_E_ARGUMENT
93The argument
94.Ar fd
95was of an unsupported file type.
96.It Bq Er ELF_E_ARGUMENT
97The argument
98.Ar sz
99was zero, or the argument
100.Ar image
101was NULL.
102.It Bq Er ELF_E_IO
103The file descriptor in argument
104.Ar fd
105was invalid.
106.It Bq Er ELF_E_IO
107The file descriptor in argument
108.Ar fd
109could not be read.
110.It Bq Er ELF_E_RESOURCE
111An out of memory condition was encountered.
112.It Bq Er ELF_E_SEQUENCE
113Functions
114.Fn elf_open
115or
116.Fn elf_openmemory
117was called before a working version was established with
118.Xr elf_version 3 .
119.El
120.Sh SEE ALSO
121.Xr elf 3 ,
122.Xr elf_begin 3 ,
123.Xr elf_errno 3 ,
124.Xr elf_memory 3 ,
125.Xr gelf 3
126