readelf coloumns

Question

Could someone explain me the column headers when you display the symbol table using readelf ?

Answer 1

You can either:

man readelf

or look at these tutorials:

• The ELF Object File Format by Dissection
• Understanding ELF using readelf and objdump.

Answer 2

Consider the Following:

`Symbol table '.symtab' contains 1203 entries:

Num: Value Size Type Bind Vis Ndx Name
310: a0008120 0 NOTYPE GLOBAL DEFAULT ABS _gp
734: a0000010 32 OBJECT GLOBAL DEFAULT 77 v
818: 9d000018 496 FUNC GLOBAL DEFAULT 71 main
849: a0000124 4 OBJECT GLOBAL DEFAULT 78 phrase
955: a0000000 9 OBJECT GLOBAL DEFAULT 77 peppers
1020: a000023c 192 OBJECT GLOBAL DEFAULT 80 bins

Num: = The Symbol number

Value = The Address of the Symbol

Size = The size of the symbol

Type = Fairly easy, it's the type of the symbol. Func = Function, etc

Bind = GLOBAL binding means the symbol is visible outside the file. LOCAL binding is visible only in the file. WEAK is like global, the symbol can be overridden.

Vis = Symbols can be default, protected, hidden or internal.

No clue what Ndx is.

Name = It's name.

Hope it helps.