119 lines
		
	
	
		
			3.1 KiB
		
	
	
	
		
			Groff
		
	
	
	
	
	
			
		
		
	
	
			119 lines
		
	
	
		
			3.1 KiB
		
	
	
	
		
			Groff
		
	
	
	
	
	
.\" Copyright (c) 2006,2008 Joseph Koshy.  All rights reserved.
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.\"
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.\" Redistribution and use in source and binary forms, with or without
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.\" modification, are permitted provided that the following conditions
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.\" are met:
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.\" 1. Redistributions of source code must retain the above copyright
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.\"    notice, this list of conditions and the following disclaimer.
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.\" 2. Redistributions in binary form must reproduce the above copyright
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.\"    notice, this list of conditions and the following disclaimer in the
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.\"    documentation and/or other materials provided with the distribution.
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.\"
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.\" This software is provided by Joseph Koshy ``as is'' and
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.\" any express or implied warranties, including, but not limited to, the
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.\" implied warranties of merchantability and fitness for a particular purpose
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.\" are disclaimed.  in no event shall Joseph Koshy be liable
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.\" for any direct, indirect, incidental, special, exemplary, or consequential
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.\" damages (including, but not limited to, procurement of substitute goods
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.\" or services; loss of use, data, or profits; or business interruption)
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.\" however caused and on any theory of liability, whether in contract, strict
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.\" liability, or tort (including negligence or otherwise) arising in any way
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.\" out of the use of this software, even if advised of the possibility of
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.\" such damage.
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.\"
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.\" $Id$
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.\"
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.Dd June 17, 2006
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.Os
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.Dt ELF_RAND 3
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.Sh NAME
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.Nm elf_rand
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.Nd provide sequential access to the next archive member
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.Sh LIBRARY
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.Lb libelf
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.Sh SYNOPSIS
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.In libelf.h
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.Ft off_t
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.Fn elf_rand "Elf *archive" "off_t offset"
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.Sh DESCRIPTION
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The
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.Fn elf_rand
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function causes the ELF descriptor
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.Ar archive
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to be adjusted so that the next call to
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.Xr elf_begin 3
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will provide access to the archive member at byte offset
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.Ar offset
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in the archive.
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Argument
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.Ar offset
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is the byte offset from the start of the archive to the beginning of
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the archive header for the desired member.
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.Pp
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Archive member offsets may be retrieved using the
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.Xr elf_getarsym 3
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function.
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.Sh RETURN VALUES
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Function
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.Fn elf_rand
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returns
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.Ar offset
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if successful or zero in case of an error.
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.Sh EXAMPLES
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To process all the members of an archive use:
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.Bd -literal -offset indent
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off_t off;
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Elf *archive, *e;
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\&...
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cmd = ELF_C_READ;
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archive = elf_begin(fd, cmd, NULL);
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while ((e = elf_begin(fd, cmd, archive)) != (Elf *) 0)
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{
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	... process `e' here ...
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	elf_end(e);
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	off = ...new value...;
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	if (elf_rand(archive, off) != off) {
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		... process error ...
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	}
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}
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elf_end(archive);
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.Ed
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.Pp
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To rewind an archive, use:
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.Bd -literal -offset indent
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Elf *archive;
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\&...
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if (elf_rand(archive, SARMAG) != SARMAG) {
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	... error ...
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}
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.Ed
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.Sh ERRORS
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Function
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.Fn elf_rand
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may fail with the following errors:
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.Bl -tag -width "[ELF_E_RESOURCE]"
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.It Bq Er ELF_E_ARGUMENT
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Argument
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.Ar archive
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was null.
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.It Bq Er ELF_E_ARGUMENT
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Argument
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.Ar archive
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was not a descriptor for an
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.Xr ar 1
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archive.
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.It Bq Er ELF_E_ARCHIVE
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Argument
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.Ar offset
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did not correspond to the start of an archive member header.
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.El
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.Sh SEE ALSO
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.Xr ar 1 ,
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.Xr elf 3 ,
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.Xr elf_begin 3 ,
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.Xr elf_end 3 ,
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.Xr elf_getarsym 3 ,
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.Xr elf_next 3 ,
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.Xr gelf 3
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