# Signal Handler Inheritance
###### tags: `APUE`
#### 整理：BY.Y, 2021/06/01
#### src:
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1. https://www.programmersought.com/article/34074981263/

### Signal handlers are "inherited but not shared"
節錄自
https://stackoverflow.com/questions/23181282/sharing-vs-inheriting-signal-handlers-on-linux

**Signal handlers are inherited.**
This means the children inherit the same handlers as the parent has.

**Signal handlers are not shared.**
Calling the parent's handlers is not the same as calling a child's handlers. As the man page says, the signal is delivered to the parent after it is delivered to the children: hence different calls.

### Self-defined Sighandler Inheritance
child會繼承parent的所有記憶體區段，包括.text section(signal handler)

為什麼exec會讓自定義的signal handler失效，最主要的原因是 exec 會覆蓋掉原本 child 的記憶體,使得自定義的函式無法被取得

> The child is a copy of the parent. For example, the child gets a copy of the parent’s data space, heap, and stack. Note that this is a copy for the child; the parent and the child do not share these portions of memory. The parent and the child share the text segment, however.
> *ref. APUE Section8.3 fork Function*
[name=SleepyCat1108]

**Who knows what piece of code would be at that address when you replace the entire text segment?**
*節錄自*[stack-overflow](https://stackoverflow.com/questions/2333637/is-it-possible-to-signal-handler-to-survive-after-exec)