## 1. Shell Basics:
-| Symbol | Definition |
+| Command | Definition |
|----------------|----------------------------------------------------------------------------------------------------------------|
| `.` | a single period refers to the current directory |
| `..` | a double period refers to the directory immediately above 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)
+| Command | Definition |
+|-------------------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| `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.
+
+| Command | Definition |
+|-------------------|------------------------------------------------------------------------------------------------------------------|
+| `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
+
+| Command | Definition |
+|---------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| `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...
Wildcards are a shell feature that makes the command line much more powerful than any GUI file managers.
+Wildcards are particularly useful when you are looking for directories, files, or file content that can
+vary along a given dimension. These wildcards can be used with any command that accepts file names or
+text strings as arguments.
-
-** Table of commonly used wildcards **
+#### Table of commonly used wildcards
| Wildcard | Matches |
|------------------------|------------------------------------------------|
| `[!a-e]` | any character that is not in the given range |
| `{software,carpentry}` | exactly one entire word from the options given |
+See the cheatsheet on regular expressions for more "wildcard" shortcuts.
+
+### b) How to redirect to a file and get input from a file ...
+
+#### Definitions:
+* **stdout**:
+* **stdin**:
+* **stderr**:
+| Command | Description |
+|---------|-------------|
+| `>` |
+| `>>` |
+| `<` |
+| `<<` |
-### 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...
projects / swc-modular-shell-hearing.git / blobdiff