Please follow and complete the free online Command Line Crash Course tutorial. This is a great, quick tutorial. Each "chapter" focuses on a command. Type the commands you see in the Do This section, and read the You Learned This section. Move on to the next chapter. You should be able to go through these in a couple of hours.
###Q1. Cheat Sheet of Commands
Make a cheat sheet for yourself: a list of at least ten commands and what they do, focused on things that are new, interesting, or otherwise worth remembering.
cat- display a whole file in the command line
less- display a whole file seperately
echo- write to standard output
grep-search for text string
cp- copy a file
mv- move a file
rm-remove a file
sort- take standard input and sort alphabetically for output
pushd- temporarily look at a different folder
popd- return to previous folder
cd ..- go to parent folder
cd ~- go to main folder
###Q2. List Files in Unix
What do the following commands do:
ls- lists files in current folder
ls -a- lists all files in current folder, including hidden ones
ls -l- lists files in more detailed format
ls -lh- lists files in detailed format and memory listing is Human readable
ls -lah- lists all files, including hidden ones, in detailed, human readable format
ls -t- lists files in order of time created
ls -Glp- lists files, without association to group name, in long format, only if in folder with a "/"
###Q3. More List Files in Unix
Explore these other ls options and pick 5 of your favorites:
ls -c- display by file's timestamp
ls -t- display in order of time created from newest
ls -r- file in reverse order
ls -u- displays files by access time
ls -1- displays one entry per line
###Q4. Xargs
What does xargs do? Give an example of how to use it.
xargstakes standard output and breaks it down to input for another command, which is not always possible to do through a regular | pipe.
find . -name "*.java" | xargs grep "Stock"
Would first search through all .java files and than, within those files, search for the word "Stock"