1.\" Copyright (c) 2006,2008 Joseph Koshy. All rights reserved. 2.\" 3.\" Redistribution and use in source and binary forms, with or without 4.\" modification, are permitted provided that the following conditions 5.\" are met: 6.\" 1. Redistributions of source code must retain the above copyright 7.\" notice, this list of conditions and the following disclaimer. 8.\" 2. Redistributions in binary form must reproduce the above copyright 9.\" notice, this list of conditions and the following disclaimer in the 10.\" documentation and/or other materials provided with the distribution. 11.\" 12.\" This software is provided by Joseph Koshy ``as is'' and 13.\" any express or implied warranties, including, but not limited to, the 14.\" implied warranties of merchantability and fitness for a particular purpose 15.\" are disclaimed. in no event shall Joseph Koshy be liable 16.\" for any direct, indirect, incidental, special, exemplary, or consequential 17.\" damages (including, but not limited to, procurement of substitute goods 18.\" or services; loss of use, data, or profits; or business interruption) 19.\" however caused and on any theory of liability, whether in contract, strict 20.\" liability, or tort (including negligence or otherwise) arising in any way 21.\" out of the use of this software, even if advised of the possibility of 22.\" such damage. 23.\" 24.\" $Id: elf_rand.3 189 2008-07-20 10:38:08Z jkoshy $ 25.\" 26.Dd June 17, 2006 27.Os 28.Dt ELF_RAND 3 29.Sh NAME 30.Nm elf_rand 31.Nd provide sequential access to the next archive member 32.Sh LIBRARY 33.Lb libelf 34.Sh SYNOPSIS 35.In libelf.h 36.Ft off_t 37.Fn elf_rand "Elf *archive" "off_t offset" 38.Sh DESCRIPTION 39The 40.Fn elf_rand 41function causes the ELF descriptor 42.Ar archive 43to be adjusted so that the next call to 44.Xr elf_begin 3 45will provide access to the archive member at byte offset 46.Ar offset 47in the archive. 48Argument 49.Ar offset 50is the byte offset from the start of the archive to the beginning of 51the archive header for the desired member. 52.Pp 53Archive member offsets may be retrieved using the 54.Xr elf_getarsym 3 55function. 56.Sh RETURN VALUES 57Function 58.Fn elf_rand 59returns 60.Ar offset 61if successful or zero in case of an error. 62.Sh EXAMPLES 63To process all the members of an archive use: 64.Bd -literal -offset indent 65off_t off; 66Elf *archive, *e; 67\&... 68cmd = ELF_C_READ; 69archive = elf_begin(fd, cmd, NULL); 70while ((e = elf_begin(fd, cmd, archive)) != (Elf *) 0) 71{ 72 ... process `e' here ... 73 elf_end(e); 74 75 off = ...new value...; 76 if (elf_rand(archive, off) != off) { 77 ... process error ... 78 } 79} 80elf_end(archive); 81.Ed 82.Pp 83To rewind an archive, use: 84.Bd -literal -offset indent 85Elf *archive; 86\&... 87if (elf_rand(archive, SARMAG) != SARMAG) { 88 ... error ... 89} 90.Ed 91.Sh ERRORS 92Function 93.Fn elf_rand 94may fail with the following errors: 95.Bl -tag -width "[ELF_E_RESOURCE]" 96.It Bq Er ELF_E_ARGUMENT 97Argument 98.Ar archive 99was null. 100.It Bq Er ELF_E_ARGUMENT 101Argument 102.Ar archive 103was not a descriptor for an 104.Xr ar 1 105archive. 106.It Bq Er ELF_E_ARCHIVE 107Argument 108.Ar offset 109did not correspond to the start of an archive member header. 110.El 111.Sh SEE ALSO 112.Xr ar 1 , 113.Xr elf 3 , 114.Xr elf_begin 3 , 115.Xr elf_end 3 , 116.Xr elf_getarsym 3 , 117.Xr elf_next 3 , 118.Xr gelf 3 119