Shell Programming and Scripting

I don't know if this is a big issue or not, but I'm having difficulties. I apoligize for the upcoming essay .

I'm writing a script, similar to a paint program that edits images, but in the form of ANSI block characters. The program so far is working. I managed to save the image into a file, but its unformatted, so Here's where I can't find a solution:

How could I save output thats already on the screen into a file?

If that can't be done, how would I be able to interactively edit the text file through the script, like move up a line or left or right for example, and delete or add a character in the file while the script is running?

All help is appreciated.

IF this is ASCII line art drawing, look into the script command. It creates a duplicate of the screen in a file, automatically.

But is there a way to capture a portion of the screen?

No, because a terminal isn't a video card -- its memory can't be directly accessed. The closest you get is 'print screen', which doesn't go where you want, and most terminals don't provide anyway.

Usually you'd keep a copy of the screen contents in your program and update it as you go along.

What about the other solution? Moving around the text file and manipulating text while the script is running?

What other solution? Script doesn't do that. It won't capture areas of the screen.

What it does is intercept all commands and text sent to the terminal as they happen. Since you're sending them in the first place, that doesn't sound too helpful.

Sorry I should've been more clear.

How could I design the script to interact with and manipulate a text file? I know cat, sed, and gawk can edit files, but they don't move around the text file. How could I move around the file and edit manipulate text?