Basic file editing

‼️ To begin, make sure you have a user account at CSC that is a member of a project which has access to the Puhti service.

☝🏻 You should also have already logged in to Puhti with SSH.

☝🏻 Note: For graphical output to work you need to log in with ssh -X cscusername@puhti.csc.fi. On Windows/macOS you also need to have an X server installed and running. See details in the previous tutorial. Another option is to use the Puhti web interface.

In the previous tutorial we downloaded a file called my-first-file.txt, made a copy of it named YourName-first-file.txt, and now we practice how to edit it!

💬 These exercises are done with the nano editor, but you can use your favorite editor too.

💡 Here’s a nano cheat sheet

Processing text files

Open the file with nano:

nano YourName-first-file.txt      # replace YourName

Edit the file. Type something there!
Exit nano with Ctrl+X, type Y to confirm saving and press enter to accept the filename.

Check that the modifications are actually there:

less YourName-first-file.txt      # replace YourName

Exit the preview with q.

Processing images and pdf files

☝🏻 Note! In case you are using the Puhti web interface, you need to open the files below from the file browser.

Download an image and a pdf:

wget https://raw.githubusercontent.com/csc-training/csc-env-eff/master/_slides/img/terminal_icon.png
wget https://raw.githubusercontent.com/csc-training/csc-env-eff/master/_slides/img/schrodingerscat.pdf

Open the image with eog or using the file browser of the Puhti web interface.
```
eog terminal_icon.png
```
Close the preview window.
Open the pdf with evince or using the file browser of the Puhti web interface.
```
evince schrodingerscat.pdf
```
Close the preview window with your mouse or by pressing Ctrl+C when the Terminal window is selected.

Create text files

You can also create files with nano. Try simply:
```
nano YourName-markdown-file.md
```
In the text file, write something (e.g. instructions for others how to replicate your file creation process), then save and close.
- May I interest you with the basic Markdown guide?
Use pwd and copy the path of your current working directory
Copy the text file to your personal computer for example with scp

‼️ Note: The following has to be typed in your personal computer’s terminal (not Puhti):
```
scp cscusername@puhti.csc.fi:/path/to/your/filename.md /path/to/local/folder
```
Look for the file on your personal computer and check that the contents match.

More information

💡 You can read more about scp and moving files from Docs CSC: Copying files using scp

💬 One way to display html files on Puhti is to go through the Allas object storage service. After configuring Allas there’s a-commands which enable publishing files on the internet. This is instructed in the Allas tutorial.