Linux

Process Management

Compile C

4-steps

  1. pre-processing
  2. compilation
  3. assembly
  4. linking

Types of Object Files

  1. Executable object file
  2. Relocatable object file
  3. Shared object file
  4. Core file

Formats of Object Files

  1. a.out
    • initial version of UNIX
  2. COFF
    • SVR3 UNIX
  3. PE
    • Win. NT
  4. ELF
    • SVR4 Linux

ELF format of a program

ELF Header
Program Header Table
.text
.rodata
.data
.bss
.symtab
.rel.text
.rel.data
.debug
.line
.strtab
Section Header Table

可參考: http://ccckmit.wikidot.com/lk:elf

Process

Instance of a program running on a computer

Process Control Block

task_struct

  1. Process Identification
    • PID, PPID, SID, UID, EUID..
  2. Process State Information
  3. Process Control Information