The Bash shell holds environment and shell variables. These variables set important environmental data for the shell. They also allow the environment to be modified and inherited by other processes. Learn how to set and unset variables, how to make shell variables into environmental variables, and how to clear these variables as well.
- [Instructor] There are two types of variables…accessible in a shell session.…Environmental variables are variables…that are defined for the current shell…and are inherited by any child processes…or child shells.…Shell variables are variables that are contained…exclusively within the shell in which they were defined.…They are often used to keep track of data…like the current working directory.…To see the environmental variables in a terminal,…type in printenv and hit Enter.…If you want to get the value of an individual variable,…you can specify it.…
Type in printenv, and for instance type in…capital SHELL and hit Enter.…Another way is to use the echo command…to print the value by typing in echo $SHELL…and hit Enter.…To see the shell variables we use the set command.…Type in set and hit Enter.…By default the set command shows shell functions…as well as variables,…which can be quite long.…To change the behavior of set do posix mode,…which doesn't show functions.…
Use the dash O posix option.…Type in set -o posix…and hit Enter.…
- Write the command that will take you to the most recent directory.
- Write the command that brings back the arguments and options from the previous line.
- Explain what extended globs can do.
- Identify the access.conf line that will restrict all users from using the cron service except for the user named bob.
- List the line that will get a list of only running services.
- Identify what typing ‘systemctl enable crond’ will do.
Skill Level Intermediate
Linux: User and Group Managementwith Grant McWilliams1h 8m Intermediate
1. Linux Shells Overview
2. Using the Bash Shell
3. Linux Processes
4. Job Scheduling
5. System Services
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