can't understand offset member in program header and section header - c

Question

I read man page. it says that
in ELF header:
e_phoff - This member holds the program header table's file offset in bytes.
e_shoff - This member holds the section header table's file offset in bytes.
In Program Header
p_offset This member holds the offset from the beginning of the file
at which the first byte of the segment resides.
In Section Header
sh_offset This member's value holds the byte offset from the beginning of the file to the first byte in the section
I'm confused. In my opinion, this means that in Elf header i can see offset to all program and section headers. And in the program header, i can see offset to the concrete segment in the file. In section header, i can see offset to the concrete section in the file. But it is not true. I found simple elf parse and i have seen this result
segment offset: 52
section offset: 6032
Program Entry point: 0x8048420
Section header list:
.interp: 0x8048154
offset: 340
.note.ABI-tag: 0x8048168
offset: 360
.note.gnu.build-id: 0x8048188
offset: 392
.gnu.hash: 0x80481ac
offset: 428
.dynsym: 0x80481e8
offset: 488
.dynstr: 0x80482b8
offset: 696
.gnu.version: 0x8048342
offset: 834
.gnu.version_r: 0x804835c
offset: 860
.rel.dyn: 0x804837c
offset: 892
.rel.plt: 0x8048394
offset: 916
.init: 0x80483ac
offset: 940
.plt: 0x80483d0
offset: 976
.plt.got: 0x8048410
offset: 1040
.text: 0x8048420
offset: 1056
.fini: 0x8048604
offset: 1540
.rodata: 0x8048618
offset: 1560
.eh_frame_hdr: 0x8048628
offset: 1576
.eh_frame: 0x8048664
offset: 1636
.init_array: 0x8049efc
offset: 3836
.fini_array: 0x8049f00
offset: 3840
.dynamic: 0x8049f04
offset: 3844
.got: 0x8049ff4
offset: 4084
.got.plt: 0x804a000
offset: 4096
.data: 0x804a018
offset: 4120
.bss: 0x804a020
offset: 4128
.comment: 0x0
offset: 4128
.symtab: 0x0
offset: 4172
.strtab: 0x0
offset: 5244
.shstrtab: 0x0
offset: 5768
Program header list
Phdr segment: 0x8048034
offset: 52
Interpreter: /lib/ld-linux.so.2
offset: 340
Text segment: 0x8048000
offset: 0
Data segment: 0x8049efc
offset: 3836
Dynamic segment: 0x8049f04
offset: 3844
Note segment: 0x8048168
offset: 360
PT_GNU_EH_FRAME: 0x8048628
offset: 1576
PT_GNU_STACK: 0x0
offset: 0
PT_GNU_RELRO: 0x8049efc
offset: 3836
As you can see Elf offset have section offset = 6032, but all sections offset less than Elf offset. Actually all sections in this program have offset like 6032 + (n * sizeof(Elf32_Shdr)). in this case, I can’t understand what does the offset in the section header mean? I thought, that it is offset in process image, but man page is talking about the offset inside the file. the same question about the offset in the program header. Please clarify what all the same mean section header offset and program header offset.
the parser is too large, so I did not attach it. But if someone needs it, I will do it

Answer 1

Actually all sections in this program have offset like 6032 + (n * sizeof(Elf32_Shdr)).
No, not all sections have this offsets, but all section entries of the section header table.
What you see is that the table is placed at a higher offset than the sections that are defined in its entries.
In your example:
At offset 1056 of the file starts the ".text" section.
At offset 6032 of the file starts the section header table. Its 14th entry (at 6032 + 13 * sizeof(Elf32_Shdr)) defines the ".text" section and gives its offset as 1056.