xref: /freebsd/contrib/elftoolchain/libelf/elf_cntl.3 (revision d4eeb02986980bf33dd56c41ceb9fc5f180c0d47)
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24.\" $Id: elf_cntl.3 3639 2018-10-14 14:07:02Z jkoshy $
25.\"
26.Dd August 9, 2006
27.Dt ELF_CNTL 3
28.Os
29.Sh NAME
30.Nm elf_cntl
31.Nd control an elf file descriptor
32.Sh LIBRARY
33.Lb libelf
34.Sh SYNOPSIS
35.In libelf.h
36.Ft int
37.Fn elf_cntl "Elf *elf" "Elf_Cmd cmd"
38.Sh DESCRIPTION
39Function
40.Fn elf_cntl
41controls the ELF library's subsequent use of the file descriptor
42used to create ELF descriptor
43.Ar elf .
44.Pp
45Argument
46.Ar cmd
47informs the library of the action to be taken:
48.Bl -tag -width "ELF_C_FDDONE"
49.It Dv ELF_C_FDDONE
50This value instructs the ELF library not to perform any further
51I/O on the file descriptor associated with argument
52.Ar elf .
53For ELF descriptors opened with mode
54.Ar ELF_C_WRITE
55or
56.Ar ELF_C_RDWR
57subsequent
58.Fn elf_update
59operations on the descriptor will fail.
60.It Dv ELF_C_FDREAD
61This value instructs the ELF library to read in all necessary
62data associated with ELF descriptor
63.Ar elf
64into memory so that the underlying file descriptor can be
65safely closed with command
66.Dv ELF_C_FDDONE .
67.El
68.Pp
69Argument
70.Ar elf
71must be an ELF descriptor associated with a file system object
72(e.g., an
73.Xr ar 1
74archive, an ELF file, or other data file).
75.Sh IMPLEMENTATION NOTES
76Due to use of
77.Xr mmap 2
78internally, this function is a no-op for ELF objects opened in
79.Dv ELF_C_READ
80mode.
81.Sh RETURN VALUES
82Function
83.Fn elf_cntl
84returns 0 on success, or -1 if an error was detected.
85.Sh ERRORS
86.Bl -tag -width "[ELF_E_RESOURCE]"
87.It Bq Er ELF_E_ARCHIVE
88Argument
89.Ar elf
90is a descriptor for an archive member.
91.It Bq Er ELF_E_ARGUMENT
92Argument
93.Ar elf
94was NULL.
95.It Bq Er ELF_E_ARGUMENT
96Argument
97.Ar cmd
98was not recognized.
99.It Bq Er ELF_E_MODE
100An
101.Dv ELF_C_FDREAD
102operation was requested on an ELF descriptor opened
103for writing.
104.El
105.Sh SEE ALSO
106.Xr elf 3 ,
107.Xr elf_begin 3 ,
108.Xr elf_end 3 ,
109.Xr elf_next 3 ,
110.Xr elf_update 3 ,
111.Xr gelf 3
112