mcs(1)mcs(1)NAMEmcs - Manipulates object file comment sections
SYNOPSISmcs [-v] [-V] [[-a|r|R data] | [-D key] | [-d] ] [-t tag] [-g flags]
Add a new subsection or append to existing subsection data. By default,
the data is treated as a character string and appended to the generic
string space subsection. Use -t to specify a subsection. Delete a sub‐
section. Use -t to specify the subsection that you want to delete.
Delete one entry within a subsection. Use -t to specify the subsection
that this operation applies to. Currently, this option can only be used
with the system subsections TAGDESC and TOOLVER. Set tag descriptor
flags for a subsection. Use -t to specify the subsection. If flag set‐
tings already exist for this tag value, they are overwritten by the new
settings. Print a subsection or the entire comment section. By
default, the whole section is dumped. Use -t to specify a subsection.
By default, raw data is dumped in hexadecimal. Special formatting can
be used for system-defined subsections.
Use with -v to view contents symbolically.
This option produces the same output as odump -cm. Use odump -j
to view compact relocations data stored in the comment section.
Replace subsection data. Use -t to specify the subsection that
you want to replace. The same data interpretation applies to
both -r and -a. Replace one entry of a subsection with the
given data. Use -t to specify the subsection that this applies
to. Currently, this option can only be used with the system sub‐
sections TAGDESC and TOOLVER. Specify subsection. Within an
object, a tag is a unique identifier; only one subsection is
permitted of each tag type. Produce verbose output. Can be used
with -p. Print version information for the mcs tool.
Character string. Character strings containing white space must be
enclosed in quotes.
For certain subsections, specially formatted data is accepted.
See Special Sections for more information. Unique identifier
for an entry within a subsection. See Special Sections for more
information. An unsigned integer value or a system-defined tag
name. Comma-separated tag descriptor flag names. See Special
Sections for more information. A Tru64 UNIX object file that
contains a comment section header. Archive files are not sup‐
ported. The object file can be a file, an executable, or a
shared library. It can be either compressed or uncompressed.
The mcs command allows users to perform operations on the comment sec‐
tion (.comment) of HP (e)COFF object files. The comment section of an
object can contain information such as the “ident” string from a source
file and other information used by components of the Tru64 UNIX devel‐
opment environment. Users can optionally add their own information to
the comment section by using the mcs tool.
Definitions for symbols related to the comment section are located in
/usr/include/scncomment.h. The symbols recognized by mcs are shortened
forms of the names defined in the header file. The symbols consist of
the names of system-defined tags and tag descriptor flags.
System-defined tag names can be used with the -t option to specify a
subsection. These tags are:
Tag descriptor flag names can be used with the -g option to specify how
other tools should treat a specified subsection. The flag names recog‐
nized by mcs are:
See Special Sections for more information on the TAGDESC and TOOLVER
Processing of the TAGDESC and TOOLVER subsections differs from other
sections due to the following factors: The -R and -D options can be
used for per-entry operations. The data entry format is unique. Sys‐
tem tools that create or modify objects rely on tag descriptor flags in
the TAGDESC section to know how to process subsections that are not
recognized by the tool. This allows new subsection types to be added
without requiring changes to system tools that control how they process
the new subsections.
Three sets of flags are supported:
Strip Combine Modify
KEEP APPEND COPY
STRIP CHOOSE DELETE
LSTRIP DELETE ERROR
The “strip” flags tell the linker or stripping tools what sub‐
sections belong in a stripped or locally-stripped object: KEEP
means do not strip. STRIP means delete if removing the symbol
table. LSTRIP means delete if removing local symbol informa‐
The “combine” flags tell tools such as the linker and mcs how to
combine data from multiple input subsections of the same type:
APPEND means to concatenate raw data for each subsection.
CHOOSE means to choose one (random) subsection's data. DELETE
tells the tools that this subsection does not belong in an out‐
put object. ERRMULT means raise an error if multiple instances
of the tag value are found. ERROR means raise an error if the
tag value identifies an unknown subsection type.
The “modify” flags tell a tool that is modifying a single object
what to do with subsections it does not understand: COPY means
output a subsection identical to the one found in the input
object. DELETE means do not output the subsection. ERROR means
raise an error if a subsection of this type is encountered.
One value from each set is defined for each subsection. The
default flag settings are KEEP, APPEND, COPY.
Flags are specified symbolically on the command line. The
accepted format is a comma-separated list of three flag names
with no white space. For example, the default flag setting for
a subsection with the tag TAG# is specified as follows:
mcs-t TAG# -gKEEP,APPEND,COPY obj
The key for a TAGDESC entry is the tag value being described.
The TOOLVER subsection accepts data of the form:
The variables tool_name and version_string are character
strings, and tool_version_number is a numeric value. For exam‐
ple, to add tool version information for a program named mytool,
the command is:
mcs-t TOOLVER -a "mytool,0,Beta, 1/1/99" obj
This creates a new entry for the tool named mytool in the
TOOLVER subsection. To update this entry, use the -R option:
mcs-t TOOLVER -R "mytool,1,SSB, 1/1/99" obj
Note that double quotes have to be passed through the shell for
strings containing white space or commas. Make sure that the
separator commas have no spaces around them.
The key for the TOOLVER entry is the tool name.
The comment section of an executable file might appear as follows:
% mcs-pv objname
Tag Length Value Flags: Strip Combine Modify
CMSTAMP 0x0 0x0 KEEP CHOOSE COPY
COMPACT_RLC 0x208 0x30 STRIP DELETE DELETE
--- freeform data --- Use odump -j to view com‐
---- end data --- END 0x0 0x0
KEEP CHOOSE COPY
If you want to delete compact relocations: % mcs-d -t COMPACT_RLC obj‐
If you want to add a subsection and specify flags for it: % mcs-a DATA
-t0x80000000 -g STRIP,APPEND,COPY objname
The new subsection, identified by a tag value of 0x80000000, contains
the string “DATA” in its associated freeform data. The flag settings
indicate that the section should be stripped if the symbol table is
removed, have data appended if objects with this section are linked or
otherwise combined, and left unchanged by an object modifier.
The following environment variables affect the execution of mcs: If
set, this path is used for the creation of a temporary file. A tempo‐
rary file is used if an input object is compressed.