greatbash

Probably most of these will work in the other shells, such as sh and zsh, but I have only test this in Bash.

Making most of Bash by learning some key ideas

Edit long commands

The man bash page says:

edit-and-execute-command (C-xC-e)
    Invoke  an  editor  on the current command line, and execute the
    result as shell commands. Bash attempts to invoke $VISUAL,
    $EDITOR, and emacs as the editor, in that order.

There are some warnings in here says Be very careful with this feature. If you cancel the edit, the original command line will be immediately executed. So if you are editing rm -rf / and invoke the editor and realize you are into something dangerous and thus cancel the edit, your rootfs will be deleted without further questions asked, then it went one says @marlar if your editor is vim, you can use :cq, it makes it exit with non-zero code, and prevents the command from execution

Review files recursively

I had to get a snapshot of the files under a directory with their file datetime and sizes. I didn't know tree

$ find /path/to/folder -type f -print0 | xargs -0 ls -l --time-style="+%F %T"
OR
man tree
       -D     Print  the  date  of the last modification time or if -c is used, the last status change time for the file
          listed.

$ tree -Dh --timefmt '%F %T' maintainable-bash/
maintainable-bash/
├── [4.0K 2022-03-14 23:09:55]  0_pre-requisites
│   ├── [4.0K 2022-03-14 23:09:55]  1_tooling
│   │   └── [ 193 2022-03-14 23:09:55]  notes.txt
│   ├── [4.0K 2022-03-14 23:09:55]  2_simplifications
│   │   ├── [4.0K 2022-03-14 23:09:55]  1_multi-line-text
│   │   │   └── [ 583 2022-03-14 23:09:55]  multi-line.sh
│   │   ├── [ 269 2022-03-14 23:09:55]  notes.txt
│   │   └── [1.5K 2022-03-14 23:09:55]  simplifications.sh
│   ├── [4.0K 2022-03-14 23:09:55]  3_dry-principle
│   │   ├── [ 159 2022-03-14 23:09:55]  bad.sh
│   │   ├── [ 981 2022-03-14 23:09:55]  calling-functions.sh
│   │   ├── [ 266 2022-03-14 23:09:55]  good.sh
│   │   └── [ 405 2022-03-14 23:09:55]  notes.txt

Get the first n char or bytes of a file

$ head -c 100 file  # returns the first 100 bytes in the file
$ tail -c 100 file  # returns the last 100 bytes in the file
man head
       -c, --bytes=[-]NUM
          print the first NUM bytes of each file; with the leading '-', print all but the last  NUM  bytes  of  each
          file