MCS(1)MCS(1)NAMEmcs - manipulate the comment section of an object file
SYNOPSISmcs [-cdpVz] [-a string] [-n name] file...
The mcs command is used to manipulate a section, by default the .com‐
ment section, in an ELF object file. It is used to add to, delete,
print, and compress the contents of a section in an ELF object file,
and print only the contents of a section in a COFF object file. mcs
cannot add, delete, or compress the contents of a section that is con‐
tained within a segment.
If the input file is an archive (see ar.h(3HEAD)), the archive is
treated as a set of individual files. For example, if the -a option is
specified, the string is appended to the comment section of each ELF
object file in the archive; if the archive member is not an ELF object
file, then it is left unchanged.
mcs must be given one or more of the options described below. It
applies, in order, each of the specified options to each file.
For operations other than delete, if the object does not already con‐
tain a section with the specified name, mcs will create a new empty
section with that name before performing the specified operation.
The following options are supported:
Appends string to the comment section of the ELF object
files. If string contains embedded blanks, it must be
enclosed in quotation marks.
Compresses the contents of the comment section of the ELF
object files. All duplicate entries are removed. The
ordering of the remaining entries is not disturbed.
Deletes the contents of the specified section from the ELF
object files. The section header for the comment section
is also removed.
Specifies the name of the section to access if other than
.comment. By default, mcs deals with the section named
.comment. This option can be used to specify another sec‐
tion. mcs can take multiple -n options to allow for speci‐
fication of multiple sections.
Prints the contents of the comment section on the standard
output. Each section printed is tagged by the name of the
file from which it was extracted, using the format
file[member_name]: for archive files and file: for other
Prints on standard error the version number of mcs.
Replaces any SHT_PROGBITS sections with zeros while
retaining the original attributes of the sections.
Example 1 Printing a file's comment section
The following entry
example% mcs-p elf.file
prints the comment section of the file elf.file.
Example 2 Appending a string to a comment section
The following entry
example% mcs-a xyz elf.file
appends string xyz to elf.file's comment section.
Example 3 Stripping a specified non-allocable section
Although used primarily with comment sections, mcs can operate on any
non-allocable section. In contrast to the strip command, which removes
a predefined selection of non-allocable sections, mcs can be used to
delete a specific section. The following entry
example% mcs-d -n .annotate elf.file
removes the section named .annotate from the file elf.file.
See attributes(5) for descriptions of the following attributes:
│ ATTRIBUTE TYPE │ ATTRIBUTE VALUE │
│Interface Stability │ Stable │
SEE ALSOar(1), as(1), ld(1), strip(1), ar.h(3HEAD), elf(3ELF), tmpnam(3C),
When mcs deletes a section using the -d option, it tries to bind
together sections of type SHT_REL and target sections pointed to by the
sh_info section header field. If one is to be deleted, mcs attempts to
delete the other of the pair.
By using the -z option, it is possible to make an object file by remov‐
ing the contents of SHT_PROGBITS sections while retaining the object
file's original structure as an ELF file. The need for use of the -z
option is limited. However, the option can be used to deliver an object
file when the contents of SHT_PROGBITS sections are not relevant.
Oct 5, 2007 MCS(1)