strip-unneeded

重新編譯程式。

[dywang@dyH gcc]$ gcc -g -o stripex1 stripex1.c

先移除除錯的資訊，以 -a 選項觀看所有 elf 檔案資訊並存檔。

[dywang@dyH gcc]$ strip --strip-debug stripex1
[dywang@dyH gcc]$ readelf -a stripex1 | tee elfad.txt

移除不需要的資訊，以 -a 選項觀看所有 elf 檔案資訊並存檔。

[dywang@dyH gcc]$ strip --strip-unneeded stripex1
[dywang@dyH gcc]$ readelf -a stripex1 | tee elfadun.txt
[dywang@dyH gcc]$ diff elfad.txt elfadun.txt

比較兩個檔案。

[dywang@dyH gcc]$ diff elfad.txt elfadun.txt | tee elfaundiff.txt

修整後的執行檔，符號項目都被移除了。

13c13
<   Start of section headers:          2592 (bytes into file)
---
>   Start of section headers:          2576 (bytes into file)
19c19
<   Number of section headers:         30
---
>   Number of section headers:         28
80,84c80
<        00000000000000fe  0000000000000000           0     0     1
<   [28] .symtab           SYMTAB           0000000000000000  000011a0
<        0000000000000618  0000000000000018          29    45     8
<   [29] .strtab           STRTAB           0000000000000000  000017b8
<        00000000000001fd  0000000000000000           0     0     1
---
>        00000000000000ee  0000000000000000           0     0     1
165,232d160
< Symbol table '.symtab' contains 65 entries:
<    Num:    Value          Size Type    Bind   Vis      Ndx Name
<      0: 0000000000000000     0 NOTYPE  LOCAL  DEFAULT  UND 
<      1: 000000000040040c     0 FUNC    LOCAL  DEFAULT   13 call_gmon_start
<      2: 0000000000600700     0 OBJECT  LOCAL  DEFAULT   18 __CTOR_LIST__
<      3: 0000000000600710     0 OBJECT  LOCAL  DEFAULT   19 __DTOR_LIST__
<      4: 0000000000600720     0 OBJECT  LOCAL  DEFAULT   20 __JCR_LIST__
<      5: 0000000000400430     0 FUNC    LOCAL  DEFAULT   13 __do_global_dtors_aux
<      6: 00000000006008f8     1 OBJECT  LOCAL  DEFAULT   25 completed.6349
<      7: 0000000000600900     8 OBJECT  LOCAL  DEFAULT   25 dtor_idx.6351
<      8: 00000000004004a0     0 FUNC    LOCAL  DEFAULT   13 frame_dummy
<      9: 0000000000600708     0 OBJECT  LOCAL  DEFAULT   18 __CTOR_END__
<     10: 00000000004006f8     0 OBJECT  LOCAL  DEFAULT   17 __FRAME_END__
<     11: 0000000000600720     0 OBJECT  LOCAL  DEFAULT   20 __JCR_END__
<     12: 00000000004005d0     0 FUNC    LOCAL  DEFAULT   13 __do_global_ctors_aux
<     13: 00000000006008ec     4 OBJECT  LOCAL  DEFAULT   24 i
<     14: 0000000000600908     4 OBJECT  LOCAL  DEFAULT   25 local.2052
<     15: 00000000006008c0     0 OBJECT  LOCAL  DEFAULT   23 _GLOBAL_OFFSET_TABLE_
<     16: 00000000006006fc     0 NOTYPE  LOCAL  DEFAULT   18 __init_array_end
<     17: 00000000006006fc     0 NOTYPE  LOCAL  DEFAULT   18 __init_array_start
<     18: 0000000000600728     0 OBJECT  LOCAL  DEFAULT   21 _DYNAMIC
<     19: 0000000000400200     0 SECTION LOCAL  DEFAULT    1 
<     20: 000000000040021c     0 SECTION LOCAL  DEFAULT    2 
<     21: 000000000040023c     0 SECTION LOCAL  DEFAULT    3 
<     22: 0000000000400260     0 SECTION LOCAL  DEFAULT    4 
<     23: 0000000000400280     0 SECTION LOCAL  DEFAULT    5 
<     24: 00000000004002e0     0 SECTION LOCAL  DEFAULT    6 
<     25: 0000000000400320     0 SECTION LOCAL  DEFAULT    7 
<     26: 0000000000400328     0 SECTION LOCAL  DEFAULT    8 
<     27: 0000000000400348     0 SECTION LOCAL  DEFAULT    9 
<     28: 0000000000400360     0 SECTION LOCAL  DEFAULT   10 
<     29: 0000000000400390     0 SECTION LOCAL  DEFAULT   11 
<     30: 00000000004003a8     0 SECTION LOCAL  DEFAULT   12 
<     31: 00000000004003e0     0 SECTION LOCAL  DEFAULT   13 
<     32: 0000000000400608     0 SECTION LOCAL  DEFAULT   14 
<     33: 0000000000400618     0 SECTION LOCAL  DEFAULT   15 
<     34: 0000000000400634     0 SECTION LOCAL  DEFAULT   16 
<     35: 0000000000400660     0 SECTION LOCAL  DEFAULT   17 
<     36: 0000000000600700     0 SECTION LOCAL  DEFAULT   18 
<     37: 0000000000600710     0 SECTION LOCAL  DEFAULT   19 
<     38: 0000000000600720     0 SECTION LOCAL  DEFAULT   20 
<     39: 0000000000600728     0 SECTION LOCAL  DEFAULT   21 
<     40: 00000000006008b8     0 SECTION LOCAL  DEFAULT   22 
<     41: 00000000006008c0     0 SECTION LOCAL  DEFAULT   23 
<     42: 00000000006008e8     0 SECTION LOCAL  DEFAULT   24 
<     43: 00000000006008f8     0 SECTION LOCAL  DEFAULT   25 
<     44: 0000000000000000     0 SECTION LOCAL  DEFAULT   26 
<     45: 00000000006008e8     0 NOTYPE  WEAK   DEFAULT   24 data_start
<     46: 0000000000000000     0 FUNC    GLOBAL DEFAULT  UND printf@@GLIBC_2.2.5
<     47: 0000000000400530     2 FUNC    GLOBAL DEFAULT   13 __libc_csu_fini
<     48: 00000000004003e0     0 FUNC    GLOBAL DEFAULT   13 _start
<     49: 0000000000000000     0 NOTYPE  WEAK   DEFAULT  UND __gmon_start__
<     50: 0000000000000000     0 NOTYPE  WEAK   DEFAULT  UND _Jv_RegisterClasses
<     51: 0000000000400608     0 FUNC    GLOBAL DEFAULT   14 _fini
<     52: 0000000000000000     0 FUNC    GLOBAL DEFAULT  UND __libc_start_main@@GLIBC_
<     53: 00000000006008f0     4 OBJECT  GLOBAL DEFAULT   24 global
<     54: 0000000000400618     4 OBJECT  GLOBAL DEFAULT   15 _IO_stdin_used
<     55: 00000000006008e8     0 NOTYPE  GLOBAL DEFAULT   24 __data_start
<     56: 0000000000400620     0 OBJECT  GLOBAL HIDDEN    15 __dso_handle
<     57: 0000000000600718     0 OBJECT  GLOBAL HIDDEN    19 __DTOR_END__
<     58: 0000000000400540   137 FUNC    GLOBAL DEFAULT   13 __libc_csu_init
<     59: 00000000006008f4     0 NOTYPE  GLOBAL DEFAULT  ABS __bss_start
<     60: 0000000000600910     0 NOTYPE  GLOBAL DEFAULT  ABS _end
<     61: 00000000006008f4     0 NOTYPE  GLOBAL DEFAULT  ABS _edata
<     62: 00000000004004c4    27 FUNC    GLOBAL DEFAULT   13 inc_func
<     63: 00000000004004df    67 FUNC    GLOBAL DEFAULT   13 main
<     64: 0000000000400390     0 FUNC    GLOBAL DEFAULT   11 _init
<

查看檔案大小，從 8195 bytes 降至 4368 bytes。

[dywang@dyH gcc]$ ll stripex1*
-rwxrwxr-x. 1 dywang dywang 4368 Sep  1 08:34 stripex1
-rw-rw-r--. 1 dywang dywang  323 Aug 31 22:19 stripex1.c