* Binutils: (binutils). The GNU binary utilities "ar", "ld", "objdump", "nm", "size", "strip", and "ranlib".

Introduction
************

This brief manual contains preliminary documentation for the GNU binary utilities (collectively version 1.90):

ar
     Create, modify, and extract from archives

nm
     List symbols from object files

objdump
     Display information from object files

ranlib
     Generate index to archive contents

size
     List section sizes and total size

strip
     Discard symbols

Copyright © 1991 Free Software Foundation, Inc.

Permission is granted to make and distribute verbatim copies of this manual provided the copyright notice and this permission notice are preserved on all copies.

Permission is granted to copy and distribute modified versions of this manual under the conditions for verbatim copying, provided also that the entire resulting derived work is distributed under the terms of a permission notice identical to this one.

Permission is granted to copy and distribute translations of this manual into another language, under the above conditions for modified versions.

ar
**

       ar [-]PMOD [ MEMBERNAME ] ARCHIVE FILES...

The GNU ar program creates, modifies, and extracts from archives.  An archive is a single file holding a collection of other files in a structure that makes it possible to retrieve the original individual files (called members of the archive).

The original files' contents, mode (permissions), timestamp, owner, and group are preserved in the archive, and may be reconstituted on extraction.

GNU ar can maintain archives whose members have names of any length; however, depending on how ar is configured on your system, a limit on member-name length may be imposed (for compatibility with archive formats maintained with other tools).  If it exists, the limit is often 15 characters (typical of formats related to a.out) or 16 characters (typical of formats related to coff).

ar is considered a binary utility because archives of this sort are most often used as libraries holding commonly needed subroutines.

ar will create an index to the symbols defined in relocatable object modules in the archive when you specify the modifier s. Once created, this index is updated in the archive whenever ar makes a change to its contents (save for the q update operation). An archive with such an index speeds up linking to the library, and allows routines in the library to call each other without regard to their placement in the archive.

You may use nm -s or nm +print-armap to list this index table.  If an archive lacks the table, another form of ar called ranlib can be used to add just the table.

ar insists on at least two arguments to execute: one keyletter specifying the operation (optionally accompanied by other keyletters specifying modifiers), and the archive name to act on.

Most operations can also accept further FILES arguments, specifying particular files to operate on.

GNU ar allows you to mix the operation code P and modifier flags MOD in any order, within the first command-line argument.

If you wish, you may begin the first command-line argument with a dash.

The P keyletter specifies what operation to execute; it may be any of the following, but you must specify only one of them:

d
     Delete modules from the archive.  Specify the names of modules to be deleted as FILES; the archive is untouched if you specify no files to delete.

     If you specify the v modifier, ar will list each module as it is deleted.

m
     Use this operation to move members in an archive.

     The ordering of members in an archive can make a difference in how programs are linked using the library, if a symbol is defined in more than one member.

     If no modifiers are used with m, any members you name in the FILES arguments are moved to the end of the archive; you can use the a, b, or i modifiers to move them to a specified place instead.

p
     Print the specified members of the archive, to the standard output file.  If the v modifier is specified, show the member name before copying its contents to standard output.

     If you specify no FILES, all the files in the archive are printed.

q
     Quick append; add FILES to the end of ARCHIVE, without checking for replacement.

     The modifiers a, b, and i do not affect this operation; new members are always placed at the end of the archive.

     The modifier v makes ar list each file as it is appended.

     Since the point of this operation is speed, the archive's symbol table index is not updated, even if it already existed; you can use ar s or ranlib explicitly to update the symbol table index.

r
     Insert FILES into ARCHIVE (with replacement). This operation differs from q in that any previously existing members are deleted if their names match those being added.

     If one of the files named in FILES doesn't exist, ar displays an error message, and leaves undisturbed any existing members of the archive matching that name.

     By default, new members are added at the end of the file; but you may use one of the modifiers a, b, or i to request placement relative to some existing member.

     The modifier v used with this operation elicits a line of output for each file inserted, along with one of the letters a or r to indicate whether the file was appended (no old member deleted) or replaced.

t
     Display a table listing the contents of ARCHIVE, or those of the files listed in FILES that are present in the archive.  Normally only the member name is shown; if you also want to see the modes (permissions), timestamp, owner, group, and size, you can request that by also specifying the v modifier.

     If you do not specify any FILES, all files in the archive are listed.

     If there is more than one file with the same name (say, fie) in an archive (say b.a), ar t b.a fie will list only the first instance; to see them all, you must ask for a complete listing---in our example, ar t b.a.

x
     Extract members (named FILES) from the archive.  You can use the v modifier with this operation, to request that ar list each name as it extracts it.

     If you do not specify any FILES, all files in the archive are extracted.

A number of modifiers (MOD) may immediately follow the P keyletter, to specify variations on an operation's behavior:

a
     Add new files after an existing member of the archive.  If you use the modifier a, the name of an existing archive member must be present as the MEMBERNAME argument, before the ARCHIVE specification.

b
     Add new files before an existing member of the archive.  If you use the modifier b, the name of an existing archive member must be present as the MEMBERNAME argument, before the ARCHIVE specification.  (same as i).

c
     Create the archive.  The specified ARCHIVE is always created if it didn't 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.

i
     Insert new files before an existing member of the archive.  If you use the modifier i, the name of an existing archive member must be present as the MEMBERNAME argument, before the ARCHIVE specification.  (same as b).

l
     This modifier is accepted but not used.

o
     Preserve the original dates of members when extracting them.  If you do not specify this modifier, files extracted from the archive will be stamped with the time of extraction.

s
     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 ar s on an archive is equivalent to running ranlib on it.

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

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

ld
**

The GNU linker ld is now described in a separate manual. See Overview (GLD: the GNU linker).

nm
**

       nm [ -a | +debug-syms ]  [ -g | +extern-only ]
           [ -s | +print-armap ]  [ -o | +print-file-name ]
           [ -n | +numeric-sort ]  [ -p | +no-sort ]
           [ -r | +reverse-sort ]  [ -u | +undefined-only ]
           [ +target BFDNAME ]
           [ OBJFILES... ]

GNU nm will list the symbols from object files OBJFILES.

The long and short forms of options, shown here as alternatives, are equivalent.

OBJFILES...
     Object files whose symbols are to be listed.  If no object files are listed as arguments, nm assumes a.out.

-a
+debug-syms
     Display debugger-only symbols; normally these are not listed.

-g
+extern-only
     Display only external symbols.

-p
+no-sort
     Don't bother to sort the symbols in any order; just print them in the order encountered.

-n
+numeric-sort
     Sort symbols numerically by their addresses, not alphabetically by their names.

-s
+print-armap
     When listing symbols from archive members, include the index: a mapping (stored in the archive by ar or ranlib) of what modules contain definitions for what names.

-o
+print-file-name
     Precede each symbol by the name of the input file where it was found, rather than identifying the input file once only before all of its symbols.

-r
+reverse-sort
     Reverse the sense of the sort (whether numeric or alphabetic); let the last come first.

+target BFDNAME
     Specify an object code format other than your system's default format. See objdump, for information on listing available formats.

-u
+undefined-only
     Display only undefined symbols (those external to each object file).

objdump
*******

       objdump [ -a ]  [ -b BFDNAME ]  [ -d ]  [ -f ]
               [ -h | +header ]  [ -i ]  [ -j SECTION ]  [ -l ]
               [ -m MACHINE ]  [ -r | +reloc ]  [ -s ]
               [ -t | +syms ]  [ -x ]
               OBJFILES...

objdump displays information about one or more object files. The options control what particular information to display.  This information is mostly useful to programmers who are working on the compilation tools, as opposed to programmers who just want their program to compile and work.

The long and short forms of options, shown here as alternatives, are equivalent.

OBJFILES...
     The object files to be examined.  When you specify archives, objdump shows information on each of the member object files.

-a
     If any files from OBJFILES are archives, display the archive header information (in a format similar to ls -l).  Besides the information you could list with ar tv, objdump -a shows the object file format of each archive member.

-b BFDNAME
     You can specify a particular object-code format for your object files as BFDNAME.  This may not be necessary; OBJDUMP can automatically recognize many formats.  For example,

          objdump -b oasys -m vax -h fu.o

     Displays summary information from the section headers (-h) of fu.o, which is explicitly identified (-m) as a Vax object file in the format produced by Oasys compilers.  You can list the formats available with the -i option.

-d
     Disassemble.  Display the assembler mnemonics for the machine instructions from OBJFILES.

-f
     File header.  Display summary information from the overall header of each file in OBJFILES.

-h
+header
     Header.  Display summary information from the section headers of the object file.

-i
     Display a list showing all architectures and object formats available for specification with -b or -m.

-j NAME
     Display information only for section NAME

-l
     Label the display (using debugging information) with the source filename and line numbers corresponding to the object code shown.

-m MACHINE
     Specify the object files OBJFILES are for architecture MACHINE.  You can list available architectures using the -i option.

-r
+reloc
     Relocation.  Print the relocation entries of the file.

-s
     Display the full contents of any sections requested.

-t
+syms
     Symbol Table.  Print the symbol table entries of the file. This is similar to the information provided by the nm program.

-x
     Display all available header information, including the symbol table and relocation entries.  Using -x is equivalent to specifying all of -a -f -h -r -t.

ranlib
******

       ranlib ARCHIVE

ranlib generates an index to the contents of an archive, and stores it in the archive.  The index lists each symbol defined by a member of an archive that is a relocatable object file.

You may use nm -s or nm +print-armap to list this index.

An archive with such an index speeds up linking to the library, and allows routines in the library to call each other without regard to their placement in the archive.

The GNU ranlib program is another form of GNU ar; running ranlib is completely equivalent to executing ar -s. See ar.

size
****

       size [ -A | -B | +format COMPATIBILITY ]
            [ +help ]  [ -d | -o | -x | +radix NUMBER ]
            [ +target BFDNAME ]  [ -V | +version ]
            OBJFILES...

The GNU size utility lists the section sizes---and the total size---for each of the object files OBJFILES in its argument list. By default, one line of output is generated for each object file or each module in an archive.

The command line options have the following meanings:

OBJFILES...
     The object files to be examined.

-A
-B
+format COMPATIBILITY
     Using one of these options, you can choose whether the output from GNU size resembles output from System V size (using -A, or +format sysv), or Berkeley size (using -B, or +format berkeley).  The default is the one-line format similar to Berkeley's.

     Here is an example of the Berkeley (default) format of output from size:

           eg$  size +format Berkeley ranlib size
          text    data    bss     dec     hex     filename
          294880  81920   11592   388392  5ed28   ranlib
          294880  81920   11888   388688  5ee50   size

     This is the same data, but displayed closer to System V conventions:

           eg$  size +format SysV ranlib size
          ranlib  :
          section         size         addr
          .text         294880         8192
          .data          81920       303104
          .bss           11592       385024
          Total         388392

          size  :
          section         size         addr
          .text         294880         8192
          .data          81920       303104
          .bss           11888       385024
          Total         388688

+help
     Show a summary of acceptable arguments and options.

-d
-o
-x
+radix NUMBER
     Using one of these options, you can control whether the size of each section is given in decimal (-d, or +radix 10); octal (-o, or +radix 8); or hexadecimal (-x, or +radix 16).  In +radix NUMBER, only the three values (8, 10, 16) are supported.  The total size is always given in two radices; decimal and hexadecimal for -d or -x output, or octal and hexadecimal if you're using -o.

+target BFDNAME
     You can specify a particular object-code format for OBJFILES as BFDNAME.  This may not be necessary; SIZE can automatically recognize many formats.  See objdump, for information on listing available formats.

-V
+version
     Display version number information on size itself.

strip
*****

       strip [ -s | +strip-all ]  [ -g | -S | +strip-debug ]
              [ -x | +discard-all ]  [ -X | +discard-locals ]
              [ -T BFDNAME ]
              OBJFILES...

GNU strip will discard all symbols from object files OBJFILES, if no options are specified; or only certain symbols, depending on its command-line options.

strip will not execute unless at least one object file is listed.

     WARNING: strip modifies the files named in its argument, rather than writing modified copies under different names.

The long and short forms of options, shown here as alternatives, are equivalent.

-s
+strip-all
     This is the default case: strip all symbol entries from OBJFILES.

-g
-S
+strip-debug
     Discard only debugging symbol information from OBJFILES.

-x
+discard-all
     Discard all symbols local to each file in OBJFILES. WARNING: Note that +discard-all discards only local symbols, in spite of its name.

-X
+discard-locals
     Discard local symbols starting with L from each file in OBJFILES.  (Some compilers produce internally-used symbols that begin with L.)

-T BFDNAME
     You can specify a particular object-code format BFDNAME for OBJFILES.  This may not be necessary; STRIP can automatically recognize many formats.  See objdump, for information on listing available formats.