1## Command functions ##
2
3The `functions` command will list all of
4the [convenience functions](https://sourceware.org/gdb/onlinedocs/gdb/Convenience-Funs.html)
5provided by GEF.
6
7- `$_base([filepath])`    -- Return the matching file's base address plus an
8  optional offset. Defaults to the current file. Note that quotes need to be
9  escaped.
10- `$_bss([offset])`       -- Return the current bss base address plus the given
11  offset.
12- `$_got([offset])`       -- Return the current bss base address plus the given
13  offset.
14- `$_heap([offset])`      -- Return the current heap base address plus an
15  optional offset.
16- `$_stack([offset])`     -- Return the current stack base address plus an
17  optional offset.
18
19These functions can be used as arguments to other commands to dynamically
20calculate values.
21
22```
23gef➤  deref -l 4 $_heap()
240x0000000000602000│+0x00: 0x0000000000000000	 ← $r8
250x0000000000602008│+0x08: 0x0000000000000021 ("!"?)
260x0000000000602010│+0x10: 0x0000000000000000	 ← $rax, $rdx
270x0000000000602018│+0x18: 0x0000000000000000
28gef➤  deref -l 4 $_heap(0x20)
290x0000000000602020│+0x00: 0x0000000000000000	 ← $rsi
300x0000000000602028│+0x08: 0x0000000000020fe1
310x0000000000602030│+0x10: 0x0000000000000000
320x0000000000602038│+0x18: 0x0000000000000000
33gef➤  deref -l 4 $_base(\"libc\")
340x00007ffff7da9000│+0x0000: 0x03010102464c457f
350x00007ffff7da9008│+0x0008: 0x0000000000000000
360x00007ffff7da9010│+0x0010: 0x00000001003e0003
370x00007ffff7da9018│+0x0018: 0x0000000000027c60
38```
39