GNU Readline Library

The GNU Readline library is an exceptional software tool that is available for free and as an open source. This library provides multiple features that enable users to edit command lines while they are being typed by the user. With the option of both Emacs and vi editing modes, it caters to the preferences of the users. Furthermore, the Readline library has a set of additional functions to facilitate maintaining a list of previously-entered command lines. Users also have the option to recall and re-edit the previously entered commands.

Moreover, the Readline library offers a crucial csh-like history expansion that can be used on previous commands. Incredibly enough, the history facilities are available as a separate library, i.e., the History library, which is constructed as part of the build process. So, the History library can also be used without GNU Readline in applications where its capabilities are required or desired.

In a nutshell, the GNU Readline library is a valuable asset for developers who aim to enhance user experience and improve the functionality of their applications. With the availability of both Emacs and vi editing modes and additional history facilities, this library stands out as a top-notch software tool.