Process Status

Comments

• IDK

  May 2006

  : Hello guys,
  : Is there a system call which i can use to get the process information of some other process using C language. some process control block or something like that
  :
  :
  I'm a noob...
  Maybe look at the source for top...
  
• nugent

  June 2006

  as far as i know there is no system command to get process info, but if you look in the /proc directory you will see a load of folder that contain only numbers, these are process ID. So if you know the pid of a process you can find certain information about that process by parsing the files in the processes folder under /proc.
  
  In the folder you'll find files like:
  
  cmdline - this holds the complete command line of the process
  
  cwd - a link to the present working directory of the process
  
  environ - contains the environment for the process (null seperated)
  
  exe - sym link to the executed command
  
  fd - a directory containing an entry for each file the process has opened, which is a symlink to the actual file
  
  maps - contains the currently mapped memory regions and their permissions
  
  mem - can be used to access the pages of a processes memory through system calls like open and fread
  
  root - a symlink that points to the processes root of the filesystem (UNIX / Linux support per-process filesystem roots, set by chroot)
  
  stat - status info of process (used by ps) [should be defined in /usr/src/linux/fs/proc/array.c]
  
  statm - info about memory status in pages
  
  status - human readable format of stat and statm
  
  you can find out pretty much anything you want to about a process by parsing these files.
  
  ------
  nugent