1. Linux Help Commands
apropos apropos keyword – Show all commands with the keyword in their description. The same as the “man -k” command.
help Bash shell help for the bash builtin command list. The help command gets help for a particular command.
man Get help from the manual for a command.
man man -k keyword – Show all commands with the keyword in their description
“man 2 kill” – Display page 2 of the kill command
manpath Determine user’s searchpath for manpages.
info Documentation on Linux commands and programs similar to the man pages but navigation is organized different.
2. Linux Job Management
at Similar to cron but run only once.
atq Lists the user’s pending jobs. If the user is the superuser, everybody’s jobs are listed.
atrm Deletes at jobs.
atrun Run jobs queued for later execution
batch Executes commands when system load levels drop below 0.8 or value specified in atrun invocation.
cron A deamon used to set commands to be run at specific times. Starts the commands in the crontab file. Used to clean up temporary files periodically in the /var/tmp and /tmp directories.
nice Run a program with modified scheduling priority.
nohup Run a command immune to hangups, with output to a non-tty.
watch Execute a program periodically showing output full screen.
3. Linux Process management
bg Starts a suspended process in the background
fg Starts a suspended process in the foreground
gitps A graphical process viewer and killer program.
jobs Lists the jobs running
kill Ex: “kill 34” – Effect: Kill or stop the process with the process ID number 34.
killall Kill processes by name. Can check for and restart processes.
pidof Find the process ID of a running program
ps Get the status of one or more processes. Options:
* u (more info)
* a (see all)
* -l (technical info)
Meanings:
* PPID-parent process ID
* PID-process ID
ps ax |more to see all processes including daemons
pstree Display the tree of running processes.
sa Generates a summary of information about users’ processes that are stored in the /var/log/pacct file.
skill Report process status.
snice Report process status.
top Display the processes that are using the most CPU resources.
CTRL-C Kills the current job.
& At the end of the command makes it run in the background.