How To Log Bash History to Syslog

Thanks, that's what I was missing: -a can have a file. Cool stuff and thanks to all for explaining it. http://unixhelp.ed.ac.uk/CGI/man-cgi?history does not mention the command line argument, http://linux.die.net/man/1/bash does.

Yup, that's what it does. Shortly speaking <() or >() in bash that creates a temporary pipe.

It's called process substitution. In this case it runs the logger command, connects its input to a file in /dev/fd, and places the name of that file in the argument list of history. I've included a small demonstration below. This is useful since the history command won't write to standard out so you can't use a normal pipe. It's more common to see process substitution used to gather output from multiple commands, see http://www.linuxjournal.com/content/shell-process-redirectio...

    $ cat writer.sh 
    #!/bin/bash
    if [[ "$#" == 1 ]]; then
        echo "Wrote to file named $1" > "$1"
    else
        echo "Wrote to stdout"
    fi

    $ ./writer.sh 
    Wrote to stdout

    $ ./writer.sh | cat
    Wrote to stdout

    $ ./writer.sh >(cat)
    Wrote to file named /dev/fd/63