Basic Commands

Typography & Comments

# lines beginning with # are comments - don't type these lines
# Enter refers to the Enter key, press to execute a command
# Ctrl+c refers to control-c (hold down the Ctrl key, then press unshifted c)
# everything is case sensitive
# run these commands in order, otherwise results will be unpredictable

Control Keys

# the following commands show the effects of some control keys:
sleep 300  # does nothing for 5 minutes
Ctrl+c  # interrupt sleep 300 and return shell prompt
Ctrl+s  # stops terminal I/O (try typing)
Ctrl+q  # resumes terminal I/O (try typing)

Pager

less /etc/passwd  # display one screen at a time (like Windows MORE)
f  # forward to next screen (Space does the same)
b  # back to previous screen
/10  # search for 10 (numerals)
/  # find next occurrence of 10
G  # go to last screen
g  # go to first screen
h  # help
Enter  # next help screen
q  # quit help
q  # quit less

Manual

man less  # online documentation for the less command, piped through less
# scroll down to read it
q  # quit less when done
man man  # online documentation for the man command, piped through less
q  # quit less when done
man mount  # administration command
q  # quit less when done
man fstab  # some files also have man pages
q  # quit less when done
man -k mail  # keyword, shows commands containing mail in the description
man -k mail | less  # page the output
q  # quit less when done

Info

info info  # GNU documentaion tool (Linux)
# use page and arrow keys to move the cursor (emacs editor commands also work)
# underlined words are links to nodes, type Enter to follow a link
H  # uppercase, list of key bindings (help)
l  # lowercase L, previous node
q  # quit info

Catenate

cat > test  # copy from the keyboard to a file (like Windows COPY CON)
line 1  # type this text
line 2  # type this text
Ctrl+d  # end of input, this will terminate your input (like Windows Ctrl+z)
cat test  # display the file contents (like Windows TYPE)

List

ls  # list files (like Windows DIR /W)
ls -a  # all - including names beginning with .
ls -l  # long - shows type, mode, links, user, group, size, modification date
ls -d  # lists directory itself, not directory contents

Wildcards

ls -d /bin/z*  # * wildcard matches zero or more characters
ls -d /bin/??  # ? wildcard matches exactly one character
ls -d /bin/[xz]*  #  [] wildcard matches one of the enclosed characters
ls -d /bin/[x-z]*  # - inside [] defines a range of characters
ls -d /bin/*[^a-z]*  # ^ if first char inside [] is logical NOT

Directories

mkdir scratch  # make directory (like Windows MD)
ls -al  # this will show your new directory
cd scratch  # change directory (like Windows CD)
pwd  # print working directory
cd  # defaults to home directory
pwd
cd -  # return to previous directory  
pwd
cd

Copy

cp .bash_history hist  # copy to another file (like Windows COPY)
ls -al
cp .bash_history scratch  # copy to directory
cd scratch
ls -al
cp ~/test .  # copy test in home dir to current dir
ls -al
cp test TEST  # these are different names (UNIX is case sensitive)
ls -al

Move

mv TEST ..  # move (like Windows MOVE) to parent directory
ls -al
ls -al ..
mv test Test  # renames (like Windows REN)
ls -al

Remove

rm Test  # remove (like Windows DEL)
ls -al
cd
pwd
rm scratch/*  # contents
ls -al scratch  # rm didn't remove files beginning with .
rm scratch/.*
ls -al scratch  # nothing here now
rmdir scratch  # removes empty directory
rm hist test TEST  # clean up
ls -al

Recursive Option

# -R (uppercase) works with ls, cp, rm, and other commands
# operates on a directory and its contents
# use with caution