라이브러리 분석 - ar / ldd

$ldd ps         linux-gate.so.1 =>  (0x00110000)         libproc-3.2.7.so => /lib/libproc-3.2.7.so (0x00b23000)         libdl.so.2 => /lib/libdl.so.2 (0x00b4c000)         libc.so.6 => /lib/libc.so.6 (0x009e1000)         /lib/ld-linux.so.2 (0x009c4000)

$ar -t libdevmapper.a bitset.o hash.o libdm-common.o libdm-file.o libdm-deptree.o libdm-string.o dbg_malloc.o pool.o libdm-iface.o

ldd 라는 녀석은 실행파일이 동적으로 사용하고 있는 라이브러리의 목록을 보여주고

ar 이라는 녀석은 라이브러리에 포함되어 있는 목록을 보여준다.

[참조 : http://www.misofruit.co.kr/seojewoo/embedded/linuxschedule/030312study.htm]

man page for ldd & ar

man ldd

LDD(1)                                                                  LDD(1) NAME        ldd - print shared library dependencies SYNOPSIS        ldd [OPTION]...  FILE... DESCRIPTION        ldd prints the shared libraries required by each program or shared library specified on the command line. OPTIONS        --version               Print the version number of ldd.        -v --verbose               Print all information, including e.g. symbol versioning information.        -u --unused               Print unused direct dependencies.        -d --data-relocs               Perform relocations and report any missing objects (ELF only).        -r --function-relocs               Perform  relocations  for  both data objects and functions, and report any missing objects or functions               (ELF only).        --help Usage information. NOTES        The standard version of ldd comes with glibc2. Libc5 came with an older version, still present  on  some  sys-        tems. The long options are not supported by the libc5 version.  On the other hand, the glibc2 version does not        support -V and only has the equivalent --version.        The libc5 version of this program will use the name of a library given on the command line as-is when it  con-        tains a ’/’; otherwise it searches for the library in the standard locations. To run it on a shared library in        the current directory, prefix the name with "./". BUGS        ldd does not work on a.out shared libraries.        ldd does not work with some extremely old a.out programs which were built before ldd support was added to  the        compiler releases.  If you use ldd on one of these programs, the program will attempt to run with argc = 0 and        the results will be unpredictable. SEE ALSO        ld.so(8), ldconfig(8) Linux Programmer’s Manual       30 October 2000                         LDD(1)

man ar

AR(1)                        GNU Development Tools                       AR(1) NAME        ar - create, modify, and extract from archives SYNOPSIS        ar [-X32_64] [-]p[mod [relpos] [count]] archive [member...] DESCRIPTION        The  GNU ar program creates, modifies, and extracts from archives.  An archive is a single file holding a col-        lection 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 can be restored on extraction.        GNU ar can maintain archives whose members have names of any length; however, depending on how ar  is  config-        ured on your system, a limit on member-name length may be imposed for compatibility with archive formats main-        tained 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 com-        monly needed subroutines.        ar creates 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.        GNU ar is designed to be compatible with two different facilities.  You can control its  activity  using  com-        mand-line  options, like the different varieties of ar on Unix systems; or, if you specify the single command-        line option -M, you can control it with a script supplied via standard input, like the  MRI  "librarian"  pro-        gram.