可以用readelf命令来查看elf文件内容，跟objdump相比，这个命令更详细。
1、 readelf -h SimpleSection.o
ELF Header: Magic: 7f 45 4c 46 02 01 01 00 00 00 00 00 00 00 00 00 45为E 4C为L 46为F Class: ELF64 Data: 2's complement, little endian Version: 1 (current) OS/ABI: UNIX - System V ABI Version: 0 Type: REL (Relocatable file) Machine: Advanced Micro Devices X86-64 Version: 0x1 Entry point address: 0x0 Start of program headers: 0 (bytes into file) Start of section headers: 1056 (bytes into file) 段表在文件中的偏移 Flags: 0x0 Size of this header: 64 (bytes) 文件头大小 Size of program headers: 0 (bytes) Number of program headers: 0 Size of section headers: 64 (bytes) 每个段表结构大小 Number of section headers: 13 段表头数目 Section header string table index: 12
2、readelf -S 查看段表结构
There are 13 section headers, starting at offset 0x420: Section Headers: [Nr] Name Type Address Offset Size EntSize Flags Link Info Align [ 0] NULL 0000000000000000 00000000 0000000000000000 0000000000000000 0 0 0 [ 1] .text PROGBITS 0000000000000000 00000040 0000000000000054 0000000000000000 AX 0 0 1 [ 2] .rela.text RELA 0000000000000000 00000310 0000000000000078 0000000000000018 I 10 1 8 [ 3] .data PROGBITS 0000000000000000 00000094 0000000000000008 0000000000000000 WA 0 0 4 [ 4] .bss NOBITS 0000000000000000 0000009c 0000000000000004 0000000000000000 WA 0 0 4 [ 5] .rodata PROGBITS 0000000000000000 0000009c 0000000000000004 0000000000000000 A 0 0 1 [ 6] .comment PROGBITS 0000000000000000 000000a0 000000000000002e 0000000000000001 MS 0 0 1 [ 7] .note.GNU-stack PROGBITS 0000000000000000 000000ce 0000000000000000 0000000000000000 0 0 1 [ 8] .eh_frame PROGBITS 0000000000000000 000000d0 0000000000000058 0000000000000000 A 0 0 8 [ 9] .rela.eh_frame RELA 0000000000000000 00000388 0000000000000030 0000000000000018 I 10 8 8 [10] .symtab SYMTAB 0000000000000000 00000128 0000000000000180 0000000000000018 11 11 8 [11] .strtab STRTAB 0000000000000000 000002a8 0000000000000066 0000000000000000 0 0 1 [12] .shstrtab STRTAB 0000000000000000 000003b8 0000000000000061 0000000000000000 0 0 1 Key to Flags: W (write), A (alloc), X (execute), M (merge), S (strings), I (info), L (link order), O (extra OS processing required), G (group), T (TLS), C (compressed), x (unknown), o (OS specific), E (exclude), l (large), p (processor specific)
There are 13 section headers, starting at offset 0x420:
目标文件大小1888字节，段表在0x420开始，每个section header 64 bytes(见头文件)
因而: 0x420 + 64*13(dec)=1056 + 832 =1888正好。
3、查看字符串表与段表字符串表内容
od --skip-bytes 0x000002a8 --read-bytes 0x66 -t x2z SimpleSection.o（参数见2中段表信息 偏移与大小）
0001250 5300 6d69 6c70 5365 6365 6974 6e6f 632e >.SimpleSection.c< 0001270 7300 6174 6974 5f63 6176 2e72 3731 3033 >.static_var.1730< 0001310 7300 6174 6974 5f63 6176 3272 312e 3337 >.static_var2.173< 0001330 0031 6c67 626f 6c61 695f 696e 5f74 6176 >1.global_init_va< 0001350 0072 6c67 626f 6c61 755f 696e 696e 5f74 >r.global_uninit_< 0001370 6176 0072 7566 636e 0031 7270 6e69 6674 >var.func1.printf< 0001410 6d00 6961 006e >.main.< 0001416
4、查看段表字符串表内容
od --skip-bytes 0x000003b8 --read-bytes 0x61 -t x1z SimpleSection.o
0001670 00 2e 73 79 6d 74 61 62 00 2e 73 74 72 74 61 62 >..symtab..strtab< 0001710 00 2e 73 68 73 74 72 74 61 62 00 2e 72 65 6c 61 >..shstrtab..rela< 0001730 2e 74 65 78 74 00 2e 64 61 74 61 00 2e 62 73 73 >.text..data..bss< 0001750 00 2e 72 6f 64 61 74 61 00 2e 63 6f 6d 6d 65 6e >..rodata..commen< 0001770 74 00 2e 6e 6f 74 65 2e 47 4e 55 2d 73 74 61 63 >t..note.GNU-stac< 0002010 6b 00 2e 72 65 6c 61 2e 65 68 5f 66 72 61 6d 65 >k..rela.eh_frame< 0002030 00 >.< 0002031
5、查看符号表信息
readelf -s SimpleSection.c （小 写 s）
Symbol table '.symtab' contains 16 entries: Num: Value(符号值) Size Type Bind Vis Ndx Name 0: 0000000000000000 0 NOTYPE LOCAL DEFAULT UND 1: 0000000000000000 0 FILE LOCAL DEFAULT ABS SimpleSection.c 2: 0000000000000000 0 SECTION LOCAL DEFAULT 1 3: 0000000000000000 0 SECTION LOCAL DEFAULT 3 4: 0000000000000000 0 SECTION LOCAL DEFAULT 4 5: 0000000000000000 0 SECTION LOCAL DEFAULT 5 6: 0000000000000004 4 OBJECT LOCAL DEFAULT 3 static_var.1730 7: 0000000000000000 4 OBJECT LOCAL DEFAULT 4 static_var2.1731 8: 0000000000000000 0 SECTION LOCAL DEFAULT 7 9: 0000000000000000 0 SECTION LOCAL DEFAULT 8 10: 0000000000000000 0 SECTION LOCAL DEFAULT 6 11: 0000000000000000 4 OBJECT GLOBAL DEFAULT 3 global_init_var 全局变量，定义在第 3 段 （.data） 12: 0000000000000004 4 OBJECT GLOBAL DEFAULT COM global_uninit_var 13: 0000000000000000 33 FUNC GLOBAL DEFAULT 1 func1 14: 0000000000000000 0 NOTYPE GLOBAL DEFAULT UND printf 15: 0000000000000021 51 FUNC GLOBAL DEFAULT 1 main