Linux is a multi-user, multi-tasking operating system that has a UNIX-like way of handling processes. Execution speed of commands can depend on a thousand tiny things. Among others, we learned a lot of new commands to visualize and handle processes. Here's a list:
Table 4-3. New commands in chapter 4: Processes
| Command | Meaning | 
|---|---|
| at | Queue jobs for later execution. | 
| atq | Lists the user's pending jobs. | 
| atrm | Deletes jobs, determined by their job number. | 
| batch | Executes commands when system load level permits. | 
| crontab | Maintain crontab files for individual users. | 
| halt | Stop the system. | 
| init run level | Process control initialization. | 
| jobs | Lists currently executing jobs. | 
| kill | Terminate a process. | 
| mesg | Control write access to your terminal. | 
| netstat | Display network connections, routing tables, interface statistics, masquerade connections and multicast memberships. | 
| nice | Run a program with modified scheduling priority. | 
| pgrep | Display processes. | 
| ps | Report process status. | 
| pstree | Display a tree of processes. | 
| reboot | Stop the system. | 
| renice | Alter priority of running processes. | 
| shutdown | Bring the system down. | 
| sleep | Delay for a specified time. | 
| time | Time a command or report resource usage. | 
| top | Display top CPU processes. | 
| uptime | Show how long the system has been running. | 
| vmstat | Report virtual memory statistics. | 
| w | Show who is logged on and what they are doing. | 
| wall | Send a message to everybody's terminals. | 
| who | Show who is logged on. | 
| write | Send a message to another user. |