--- /dev/null
+# Basic Shell Commands
+***
+
+## 1. Shell Basics:
+* **`.`** (a single period) --> refers to the current directory
+* **`..`** (a double period) --> refers to the directory above the current directory
+* **`~`** --> refers to your home directory. _Note:_ this command does NOT work on Windows machines (Mac and Linux are okay)
+* **`*`** --> wildcard (multiple characters). `*.txt` will match all files in the current directory that end with `.txt`
+* **`?`** --> wildcard (single character). `?.txt` will match `a.txt` and `b.txt`, but not `ab.txt`
+* **`cd ./dirname`** --> changes the current directory to the directory `dirname`
+* **`ls -F`** --> tells you what files and directories are in the current directory
+
+
+
+## 2. Creating Things:
+### a) How to create new files and directories...
+* **`mkdir ./dirname`** --> makes a new directory called dirname below the current directory. _Note:_ Windows users will need to use `\` instead of `/` for the path separator
+* **`nano filename`** --> if `filename` does not exist, `nano` creates it and opens the `nano` text editor. If the file exists, `nano` opens it. _Note:_ _(i)_ You can use a different text editor if you like. In gnome Linux, `gedit` works really well too. _(ii)_ `nano` (or `gedit`) create text files. It doesn't matter what the file extension is (or if there is one)
+
+### b) How to delete files and directories...
+#### _Remember that deleting is forever. There is NO going back_
+* **`rm ./filename`** --> deletes a file called `filename` from the current directory
+* **`rmdir ./dirname`** --> deletes the directory `dirname` from the current directory. _Note:_ `dirname` must be empty for `rmdir` to run.
+
+### c) How to copy and rename files and directories...
+* **`mv tmp/filename .`** --> moves the file `filename` from the directory `tmp` to the current directory. _Note:_ _(i)_ the original `filename` in `tmp` is deleted. _(ii)_ `mv` can also be used to rename files (e.g., `mv filename newname`
+* **`cp tmp/filename .`** --> copies the file `filename` from the directory `tmp` to the current directory. _Note:_ _(i)_ the original file is still there
+
+
+
+## 3. Pipes and Filters
+### a) How to use wildcards to match filenames...
+### b) That wildcards are expanded by the shell before commands are run...
+### c) How to redirect a command's output to a file...
+### d) How to redirect a command's input from a file...
+### e) How to use the output of one command as the input to another with a pipe...
+### f) That combining single-purpose filters with pipes is the most productive way to use the shell...
+### g) That if a program conforms to Unix conventions, it can easily be combined with others...
+
+
+
+## 4. Variables
+### a) Assignment
+* **`varname=1`** -->
+
+### b) Indexing
+* **`varname[0]`** --> _Note:_ the shell is zero indexed. That means you always start counting from zero
+
+### c) Referencing
+* **`${varname}` -->
+* **`${varname[@]` -->
+
+
+
+## 5. Loops
+NEED TO DO VARIABLE ASSIGNMENT FIRST!!!!
+### a) How to repeat operations using a loop...
+* **`for`** -->
+ `for filename in *.dat
+ do
+ mv ${filename} ${newname}
+ done`
+
+* **`while`** -->
+ `count=0
+ while ${count} -lte 6
+ do
+ COMMAND HERE
+ done`
+
+### b) That the loop variable takes on a different value each time through the loop...
+### c) The difference between a variable's name and its value...
+### d) Why spaces and some punctuation characters shouldn't be used in files' names...
+### e) How to display history and re-use commands...
+* **`history`** --> displays your command history to the standard output (usually the screen)
+
+
+
+## 6. Shell Scripts
+### a) How to store shell commands in a file...
+### b) How to run a shell script...
+### c) How to pass filenames into a shell script...
+
+
+
+## 7. Finding Things
+### a) How to select lines matching patterns in text files...
+* **`grep [options] day haiku.txt`** --> finds every instance of the string `day` in the file haiku.txt and pipes it to standard output.
+ * **`-E`** --> tells grep you will be using a regular expression. Enclose the regular expression in quotes. _Note:_ the power of `grep` comes from using regular expressions. Please see the regular expressions sheet for examples
+ * **`-i`** --> makes matching case-insensitive
+ * **`-n`** --> limits the number of lines that match to the first n matches
+ * **`-v`** --> shows lines that do not match the pattern (inverts the match)
+ * **`-w`** --> outputs instances where the pattern is a whole word
+
+### b) How to find files with certain properties...
+* **`find . -type d` -->
+ * **`-type [df]`** --> d lists directories; f lists files
+ * **`-maxdepth n`** --> `find` automatically searches subdirectories. If you don't want that, specify the number of levels below the working directory you would like to search
+ * **`-mindepth n`** --> starts `find`'s search n levels below the working directory
+
+### c) How to use one command's output as arguments to another command...
+
+### d) How are text and binary files different?...
+