Guys guys. Try pressing CTRL+S on the Repl…
Julia 1.13.2
Nice feature, but perhaps not the best hotkey? CTRL+S is “save” everywhere else.
That’s not true: in Emacs, and all Emacs-inspired keybindings (like most shells, and REPLs, including ipython), Ctrl+S is, surprise, the search functionality. So, in fact, Ctrl+S (and Ctrl+R) is a very standard keybinding for searching through the history.
I didn’t know that either! Very useful. 
By the way, in BASH it is not used for search:
Ctrl+S normally pauses terminal output (XOFF), rather than saving anything.
That’s not bash, but your terminal emulator overriding Ctrl+S. In bash, Ctrl+S is by default the forward search in the shell history, precisely like Emacs (well, in Emacs the search is in the buffer, not the history, but the idea of reverse and forward search is the same).