Chapter 1 Flashcards
(38 cards)
Shell
Program that accepts and interprets text-mode commands and provides an interface to the system
4
Environment variables
placeholders for data that may be useful to many programs
4
bash
most common default shell for user accounts
4
sh
the Bourne shell
4
tcsh
based on csh (a C shell). No major distros. similar to bash
5
csh
the original C-shell
5
ksh
the Korn shell. Bourne shell and the C shell extended
5
zsh
the Z shell takes the Korn shell to the next level
5
2 types of default shells
default interactive shell
default system shell
5
/bin/sh
a pointer to the system’s default system shell
5
uname
command showing which OS is being run
6
cd
change directory
6
~
home directory
6
echo
displays the text that you enter
7
time
tells you how long the system took to execute a command
7
set
displays a wide variety of options relating to bash shell operation. These options are formatted much like environment variables, but they aren’t the same things.
7
exit vs logout
exit terminates any shell
logout terminates only login shells
7
Login shells
shell programs that are launched automatically when you initiate a textmode login as opposed to those that run in xterm windows or on other terminal emulators
7
-a
shows if there are internal commands with installed duplicate external commands
7
what happens when you type a command that the shell does not recognize as one of its internal commands?
the shell checks its path to find a program by that name to execute it
8
command completion
type part of the command or a filename (as an option to the command or filename and press tab and the shell fills in the rest of it
9
How long can filenames be?
up to 255 characters
10
Retrieve command
Pressing the up button on the command line. It repeats the previous command. Guess what down does.
10
backward/reverse search
Press Ctrl+R and begin typing characters that should be unique to the command from anywhere inside the command
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