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bit 0.4.90 (Default branch)
11-03-2008
bit is a library that makes it easier to dynamically manipulate data buffers containing fields that do not have octet (byte) boundaries. An example is the IP header, which is generally dealt with at compile time via bit fields in a structure. A key feature of the bit library is support for loading data formats described in XML files and dynamically parsing those fields at run time. This library was initially created to support reading various kinds of robotic device I/O (IR sensors, motors), but it has also been used for run time parsing of IP, TCP, UDP, and RTP headers. License: GNU General Public License v3 Changes:|
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elf_flag(3E) elf_flag(3E) NAME
elf_flagdata, elf_flagehdr, elf_flagelf, elf_flagphdr, elf_flagscn, elf_flagshdr - manipulate flags SYNOPSIS
[flag... ] file... [library] ... DESCRIPTION
These functions manipulate the flags associated with various structures of an ELF file. Given an ELF descriptor elf, a data descriptor data, or a section descriptor scn, the functions may set or clear the associated status bits, returning the updated bits. A null descriptor is allowed, to simplify error handling; all functions return zero for this degenerate case. cmd may have the following values: The functions clear the bits that are asserted in flags. Only the non-zero bits in flags are cleared; zero bits do not change the status of the descriptor. The functions set the bits that are asserted in flags. Only the non-zero bits in flags are set; zero bits do not change the status of the descriptor. Descriptions of the defined flags bits appear below. When the program intends to write an ELF file, this flag asserts the associated information needs to be written to the file. Thus, for example, a program that wished to update the ELF header of an existing file would call with this bit set in flags and cmd equal to A later call to would write the marked header to the file. Normally, the library decides how to arrange an output file. That is, it automatically decides where to place sections, how to align them in the file, etc. If this bit is set for an ELF descriptor, the program assumes responsibility for determining all file positions. This bit is meaningful only for and applies to the entire file associated with the descriptor. When a flag bit is set for an item, it affects all the subitems as well. Thus, for example, if the program sets the bit with the entire logical file is ``dirty.'' EXAMPLES
The following fragment shows how one might mark the ELF header to be written to the output file. SEE ALSO
elf(3E), elf_end(3E), elf_getdata(3E), elf_getehdr(3E), elf_update(3E). elf_flag(3E)