Linux 5
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- What kind of variable can you name & assign a value to? What kind is already named but you can still change value for?
- user and environment
- The default for a variable is that it is only seen by process which it was defined (not to parent processes). This is referred to as?
- private or local variables
- to make a variable global, use this built in command?
- export
- To see the value of a variable name type:
- echo $variable name
- These are short user variables designed to rename proper commands to something shorter or easier to remember?
- aliases
- the syntax for creating an alias is?
- alias name="command"
- where must aliases be entered for system wide use
- /etc/bashrc
- you can define your own personal aliases by modifying this file in your home directory
- .bashrc
- You normally need to logout & back in for .bashrc aliases to take affect. However, you can activate them immediately by typing:
- "source .bashrc" or ". .bashrc"
- Which command would you use to check the value for the variable DISPLAY?
- echo $DISPLAY
- You changed several environment variables in the bash shell. Which command will allow you to make your changes available to the child processes?
- export VARIABLENAME
- To add another directory to your path, issue this command?
- PATH=$PATH:/directory_name; export PATH
- To permanently modify your path, edit this file in your home directory?
- .bash_profile
- To change a path for all users edit this file?
- /etc/profile
- How do you run a command that is not in your working directory? If the command is in your home directory?
- ./command, ~/command
- What command can you run to see the value of your prompt, path, etc..?
- printenv
- What command would you type to temporarily add the date/time to your shell prompt?
- PS1='Date: \d Time: \t->>'; export PS1
- To modify the prompt so it shows the shell and current directory, type the command
- PS1='\s:\w' ; export PS1
- To make the change in your prompt permanent edit 1 of these files?
- .bash_profile or .profile
- What's the default name of the event history log in your home directory?
- .bash_history
- you can review prior commands typed by typing this?
- history "x" (where "x"= # of prior commands to view).
- what built in command would you use to see or run the last 17 entries of your history file?
- fc -l
- To make a command run in the background, use this option?
- &
- Use this command to suspend a running program & put it in the background? Use this command to bring back to foreground? Used this to kill the process?
- CTRL+Z, fg, CTRL+C
- To see a list of currently running processes use this command?
- ps
- This util lets you look at running processes, stats on memory & the swap file?
- top
- This command can be used to lower the priority of a running process?
- nice
- When using nice, what is the highest priority that can be given to a process? The lowest?
- -20 highest, 19 lowest
- This command allows you to see a list of commands that are running in the background and which jobs are stopped or suspended.
- jobs
- What command will allow a suspeneded job to be brought to the foreground? What switch allows you to specificy specific job
- fg, fg $name