Readline-based command line utility for shell scripting

It is a simple C program that allows you to easily integrate readline into your shell scripts and shell functions.

Usage:

$ readline -d message.txt -p "Enter message: " -H history
Enter message: Hello
$ cat message.txt
Hello
$ cat history
Hello

When you run readline again, "Hello" will be in the history.

$ readline -h

readlinesh usage: readline <options...>

 -d <destination>  -- Where to write the line (default stdout)
 -H <history>      -- History file (default ~/.readline-history)
 -p <prompt>       -- The prompt (default "> ")

The line is written to history even on Ctrl-C.
Use Ctrl-D on a blank line to cancel and skip writing to history.

Git-based example

Here is an example of using readline to input your Git commit messages with history and without loading your editor. Put this shell function in your shell startup scripts:

gm()
# Git-Commit with Message
{
  local MESSAGE_FILE=$( mktemp )
  readline -d $MESSAGE_FILE \
           -p "Enter commit message: " \
           -H ~/.git-history \
    || return 1
  git commit ${*} --file=$MESSAGE_FILE
  rm $MESSAGE_FILE
}

Then you can do:

$ ls
... directory ...
$ git status
... git information ...
$ gm myfile.c
Enter commit message: This is my change to myfile.c

You have full-featured line editing and history without losing your view of the previous output. If you cancel gm with Ctrl+C or Ctrl+D it will exit cleanly without running git commit.

Installation

Be sure you have the libreadline and libhistory development packages for your system. On Debian and Ubuntu this is APT package libreadline-dev. Then do:

$ git clone https://github.com/jmjwozniak/readlinesh.git
$ cd readlinesh
$ ./autogen.sh
$ ./configure --prefix=$HOME/readlinesh
$ make install
# Test:
$ $HOME/readlinesh/bin/readline

Non-standard libreadline location

If you have libreadline/libhistory in a non-standard location, such as a from-source installation or an Anaconda environment, use something like:

Anaconda

This pattern works for Linux or Mac.

$ C=$HOME/path/to/conda"
$ export CFLAGS="-I$C/include"
$ export LDFLAGS="-L$C/lib -Wl,-rpath -Wl,$C/lib"
$ export LIBS="-lhistory"
$ ./configure --prefix=...
$ make install

Mac Homebrew

$ C=/usr/local/opt/readline
$ export CFLAGS="-I$C/include"
$ export LDFLAGS="-L$C/lib"
$ export LIBS="-lhistory"
$ ./configure --prefix=...
$ make install