binutils.texi

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are extracted.

@end table

A number of modifiers (@var{mod}) may immediately follow the @var{p}
keyletter, to specify variations on an operation's behavior:

@table @code
@item a
@cindex relative placement in archive
Add new files @emph{after} an existing member of the
archive.  If you use the modifier @samp{a}, the name of an existing archive
member must be present as the @var{relpos} argument, before the
@var{archive} specification.

@item b
Add new files @emph{before} an existing member of the
archive.  If you use the modifier @samp{b}, the name of an existing archive
member must be present as the @var{relpos} argument, before the
@var{archive} specification.  (same as @samp{i}).

@item c
@cindex creating archives
@emph{Create} the archive.  The specified @var{archive} is always
created if it did not exist, when you request an update.  But a warning is
issued unless you specify in advance that you expect to create it, by
using this modifier.

@item f
Truncate names in the archive.  @sc{gnu} @code{ar} will normally permit file
names of any length.  This will cause it to create archives which are
not compatible with the native @code{ar} program on some systems.  If
this is a concern, the @samp{f} modifier may be used to truncate file
names when putting them in the archive.

@item i
Insert new files @emph{before} an existing member of the
archive.  If you use the modifier @samp{i}, the name of an existing archive
member must be present as the @var{relpos} argument, before the
@var{archive} specification.  (same as @samp{b}).

@item l
This modifier is accepted but not used.
@c whaffor ar l modifier??? presumably compat; with
@c what???---doc@@cygnus.com, 25jan91 

@item N
Uses the @var{count} parameter.  This is used if there are multiple
entries in the archive with the same name.  Extract or delete instance
@var{count} of the given name from the archive.

@item o
@cindex dates in archive
Preserve the @emph{original} dates of members when extracting them.  If
you do not specify this modifier, files extracted from the archive
are stamped with the time of extraction.

@item P
Use the full path name when matching names in the archive.  @sc{gnu}
@code{ar} can not create an archive with a full path name (such archives
are not POSIX complaint), but other archive creators can.  This option
will cause @sc{gnu} @code{ar} to match file names using a complete path
name, which can be convenient when extracting a single file from an
archive created by another tool.

@item s
@cindex writing archive index
Write an object-file index into the archive, or update an existing one,
even if no other change is made to the archive.  You may use this modifier
flag either with any operation, or alone.  Running @samp{ar s} on an
archive is equivalent to running @samp{ranlib} on it.

@item S
@cindex not writing archive index
Do not generate an archive symbol table.  This can speed up building a
large library in several steps.  The resulting archive can not be used
with the linker.  In order to build a symbol table, you must omit the
@samp{S} modifier on the last execution of @samp{ar}, or you must run
@samp{ranlib} on the archive.

@item u
@cindex updating an archive
Normally, @samp{ar r}@dots{} inserts all files
listed into the archive.  If you would like to insert @emph{only} those
of the files you list that are newer than existing members of the same
names, use this modifier.  The @samp{u} modifier is allowed only for the
operation @samp{r} (replace).  In particular, the combination @samp{qu} is
not allowed, since checking the timestamps would lose any speed
advantage from the operation @samp{q}.

@item v
This modifier requests the @emph{verbose} version of an operation.  Many
operations display additional information, such as filenames processed,
when the modifier @samp{v} is appended.

@item V
This modifier shows the version number of @code{ar}.
@end table

@code{ar} ignores an initial option spelt @code{-X32_64}, for
compatibility with AIX.  The behaviour produced by this option is the
default for GNU @code{ar}.  @code{ar} does not support any of the other
@code{-X} options; in particular, it does not support @code{-X32}
which is the default for AIX @code{ar}.

@node ar scripts
@section Controlling @code{ar} with a script

@smallexample
ar -M [ <@var{script} ]
@end smallexample

@cindex MRI compatibility, @code{ar}
@cindex scripts, @code{ar}
If you use the single command-line option @samp{-M} with @code{ar}, you
can control its operation with a rudimentary command language.  This
form of @code{ar} operates interactively if standard input is coming
directly from a terminal.  During interactive use, @code{ar} prompts for
input (the prompt is @samp{AR >}), and continues executing even after
errors.  If you redirect standard input to a script file, no prompts are
issued, and @code{ar} abandons execution (with a nonzero exit code)
on any error.

The @code{ar} command language is @emph{not} designed to be equivalent
to the command-line options; in fact, it provides somewhat less control
over archives.  The only purpose of the command language is to ease the
transition to @sc{gnu} @code{ar} for developers who already have scripts
written for the MRI ``librarian'' program.

The syntax for the @code{ar} command language is straightforward:
@itemize @bullet
@item
commands are recognized in upper or lower case; for example, @code{LIST}
is the same as @code{list}.  In the following descriptions, commands are
shown in upper case for clarity.

@item
a single command may appear on each line; it is the first word on the
line.

@item
empty lines are allowed, and have no effect.

@item
comments are allowed; text after either of the characters @samp{*}
or @samp{;} is ignored.

@item
Whenever you use a list of names as part of the argument to an @code{ar}
command, you can separate the individual names with either commas or
blanks.  Commas are shown in the explanations below, for clarity.

@item
@samp{+} is used as a line continuation character; if @samp{+} appears
at the end of a line, the text on the following line is considered part
of the current command.
@end itemize

Here are the commands you can use in @code{ar} scripts, or when using
@code{ar} interactively.  Three of them have special significance:

@code{OPEN} or @code{CREATE} specify a @dfn{current archive}, which is
a temporary file required for most of the other commands.

@code{SAVE} commits the changes so far specified by the script.  Prior
to @code{SAVE}, commands affect only the temporary copy of the current
archive.

@table @code
@item ADDLIB @var{archive} 
@itemx ADDLIB @var{archive} (@var{module}, @var{module}, @dots{} @var{module})
Add all the contents of @var{archive} (or, if specified, each named
@var{module} from @var{archive}) to the current archive.

Requires prior use of @code{OPEN} or @code{CREATE}.

@item ADDMOD @var{member}, @var{member}, @dots{} @var{member}
@c FIXME! w/Replacement??  If so, like "ar r @var{archive} @var{names}"
@c        else like "ar q..."
Add each named @var{member} as a module in the current archive.

Requires prior use of @code{OPEN} or @code{CREATE}.

@item CLEAR
Discard the contents of the current archive, canceling the effect of
any operations since the last @code{SAVE}.  May be executed (with no
effect) even if  no current archive is specified.

@item CREATE @var{archive}
Creates an archive, and makes it the current archive (required for many
other commands).  The new archive is created with a temporary name; it
is not actually saved as @var{archive} until you use @code{SAVE}.
You can overwrite existing archives; similarly, the contents of any
existing file named @var{archive} will not be destroyed until @code{SAVE}.

@item DELETE @var{module}, @var{module}, @dots{} @var{module}
Delete each listed @var{module} from the current archive; equivalent to
@samp{ar -d @var{archive} @var{module} @dots{} @var{module}}.

Requires prior use of @code{OPEN} or @code{CREATE}.

@item DIRECTORY @var{archive} (@var{module}, @dots{} @var{module})
@itemx DIRECTORY @var{archive} (@var{module}, @dots{} @var{module}) @var{outputfile}
List each named @var{module} present in @var{archive}.  The separate
command @code{VERBOSE} specifies the form of the output: when verbose
output is off, output is like that of @samp{ar -t @var{archive}
@var{module}@dots{}}.  When verbose output is on, the listing is like
@samp{ar -tv @var{archive} @var{module}@dots{}}.

Output normally goes to the standard output stream; however, if you
specify @var{outputfile} as a final argument, @code{ar} directs the
output to that file.

@item END
Exit from @code{ar}, with a @code{0} exit code to indicate successful
completion.  This command does not save the output file; if you have
changed the current archive since the last @code{SAVE} command, those
changes are lost.

@item EXTRACT @var{module}, @var{module}, @dots{} @var{module}
Extract each named @var{module} from the current archive, writing them
into the current directory as separate files.  Equivalent to @samp{ar -x
@var{archive} @var{module}@dots{}}.

Requires prior use of @code{OPEN} or @code{CREATE}.

@ignore
@c FIXME Tokens but no commands???
@item FULLDIR

@item HELP
@end ignore

@item LIST
Display full contents of the current archive, in ``verbose'' style
regardless of the state of @code{VERBOSE}.  The effect is like @samp{ar
tv @var{archive}}.  (This single command is a @sc{gnu} @code{ar}
enhancement, rather than present for MRI compatibility.)

Requires prior use of @code{OPEN} or @code{CREATE}.

@item OPEN @var{archive}
Opens an existing archive for use as the current archive (required for
many other commands).  Any changes as the result of subsequent commands
will not actually affect @var{archive} until you next use @code{SAVE}.

@item REPLACE @var{module}, @var{module}, @dots{} @var{module}
In the current archive, replace each existing @var{module} (named in
the @code{REPLACE} arguments) from files in the current working directory.
To execute this command without errors, both the file, and the module in
the current archive, must exist. 

Requires prior use of @code{OPEN} or @code{CREATE}.

@item VERBOSE
Toggle an internal flag governing the output from @code{DIRECTORY}.
When the flag is on, @code{DIRECTORY} output matches output from
@samp{ar -tv }@dots{}.

@item SAVE
Commit your changes to the current archive, and actually save it as a
file with the name specified in the last @code{CREATE} or @code{OPEN}
command. 

Requires prior use of @code{OPEN} or @code{CREATE}.

@end table

@iftex
@node ld
@chapter ld
@cindex linker
@kindex ld
The @sc{gnu} linker @code{ld} is now described in a separate manual.
@xref{Top,, Overview,, Using LD: the @sc{gnu} linker}.
@end iftex

@node nm
@chapter nm
@cindex symbols
@kindex nm

@smallexample
nm [ -a | --debug-syms ]  [ -g | --extern-only ]
   [ -B ]  [ -C | --demangle[=@var{style}] ] [ -D | --dynamic ]
   [ -s | --print-armap ]  [ -A | -o | --print-file-name ]
   [ -n | -v | --numeric-sort ]  [ -p | --no-sort ]
   [ -r | --reverse-sort ]  [ --size-sort ] [ -u | --undefined-only ]
   [ -t @var{radix} | --radix=@var{radix} ] [ -P | --portability ]
   [ --target=@var{bfdname} ] [ -f @var{format} | --format=@var{format} ]
   [ --defined-only ] [-l | --line-numbers ]  [ --no-demangle ]
   [ -V | --version ]  [ -X 32_64 ]  [ --help ]  [ @var{objfile}@dots{} ]
@end smallexample

@sc{gnu} @code{nm} lists the symbols from object files @var{objfile}@dots{}.
If no object files are listed as arguments, @code{nm} assumes the file
@file{a.out}.

For each symbol, @code{nm} shows:

@itemize @bullet
@item
The symbol value, in the radix selected by options (see below), or
hexadecimal by default.

@item
The symbol type.  At least the following types are used; others are, as
well, depending on the object file format.  If lowercase, the symbol is
local; if uppercase, the symbol is global (external).

@c Some more detail on exactly what these symbol types are used for
@c would be nice.
@table @code
@item A
The symbol's value is absolute, and will not be changed by further
linking.

@item B
The symbol is in the uninitialized data section (known as BSS).

@item C
The symbol is common.  Common symbols are uninitialized data.  When
linking, multiple common symbols may appear with the same name.  If the
symbol is defined anywhere, the common symbols are treated as undefined
references.  For more details on common symbols, see the discussion of
--warn-common in @ref{Options,,Linker options,ld.info,The GNU linker}.

@item D
The symbol is in the initialized data section.

@item G
The symbol is in an initialized data section for small objects.  Some
object file formats permit more efficient access to small data objects,
such as a global int variable as opposed to a large global array.

@item I
The symbol is an indirect reference to another symbol.  This is a GNU
extension to the a.out object file format which is rarely used.

@item N
The symbol is a debugging symbol.

@item R
The symbol is in a read only data section.

@item S
The symbol is in an uninitialized data section for small objects.

@item T
The symbol is in the text (code) section.