Memory Layout of a Program in UNIX

Memory layout of a Program in a UNIX-environment:



Reference : "The Environment of a Unix Process" in Advanced Programming in the UNIX Environment Richard Stevens, p.168

(High address)
+-------------------+
|                   |  cmd line args and env vars
|                   |
+-------------------+
|    stack          | 
+-------------------+
|       ↓           |
|                   |
|       ↑           |
+-------------------+
|    heap           | 
+-------------------+
|Uninitialized data | init to zero by exec
|   (bss)           |
+-------------------+  _
| initialized data  |   |
+-------------------+   |--read from program file by exec
|    text           |   |
+-------------------+  _|
(Low address)