M: I’ve got a directory of straight text files. Can you give me a minimal set of Linux commands to collect them into a single file that can be recognized as an e-book by the program calibre? Complexity isn’t necessary, just for it to be in a format that the program can then convert into a more friendly format.

G: You can concatenate the text files into a single file and then convert it to an e-book format using Calibre’s command-line tools. Here's a minimal approach:

cat *.txt > combined.txt
ebook-convert combined.txt combined.epub

This will create a basic EPUB file, which Calibre can then convert to other formats like MOBI or PDF. If you want better formatting, you might consider wrapping the text in basic HTML:

echo "<html><body><pre>" > combined.html
cat *.txt >> combined.html
echo "</pre></body></html>" >> combined.html
ebook-convert combined.html combined.epub

This will help preserve line breaks and make it more readable.

M: What command appends the result of a cat command to a text file instead of replacing it

G: To append the result of a cat command to a text file instead of replacing it, use >> instead of >.

For example:

cat file1.txt file2.txt >> combined.txt

This appends file1.txt and file2.txt to combined.txt without overwriting its existing content.