Adding Some Spice To *nix Shell Scripts

An anonymous reader writes "Developing GUI script-based applications is time-consuming and expensive. Most Unix-based scripts run in a CLI mode or over a secure ssh session. The Unix shells are quite sophisticated programming languages in their own right: they are easy to design and quick to build, but they are not user-friendly in the same way the Unix commands aren't (see the Unix haters books). Both Unix and bash provide features for writing user friendly scripts using various tools to build powerful, interactive, user-friendly scripts that run under the bash shell on Linux or Unix. What tools do you use that spice up your scripts on the Linux or Unix platforms?"

Comments

tools I found useful

[tpwch]

Here are some random things I find useful, related to user interaction (mostly becuase it notifies the user):

Oven timer:
sleep $((20*60)); xmessage "Dinner is done"

Quick macro for automating some repetitive task in a program:
xdotool type "something"; xdotool key Return; xdotool mousemove $x $y; xdotool click 1; (and so on)

Copying a file to/from the clipboard (can also copy from /topipe, so the output of any command). Faster than opening a text editor:
xclip -in file

Notifying me when some specific thing changed on a website:
CHECKLINE="$(curl -s http://somewebsite.org/somepage.html | grep "currently undergoing maintenence")"
while true; do
    sleep 120
    [ -z "$CHECKLINE" ] && xmessage "somewebsite is open again" && exit
done

Or just checking for changes in general (I use this for notifying me when something changed when tracking something I ordered, so I know the minute the package is ready to get picked up at the post office):
while true; do
    OLD_MD5=${MD5}
    CONTENT=$(elinks -dump 1 -dump-charset iso-8859-1 "http://someurl.com/track?id=someid")
    MD5=$(echo -n $CONTENT | md5sum -)

    [ "${MD5}" != "${OLD_MD5}" ] && {
        xmessage "$(printf "New action: :\n\n${CONTENT}")"
    }
    sleep 120
done

If you don't want to interrupt what you're doing with a pop-up you can pipe it to osd_cat instead to have the text appear over whatever program you're currently working with. Adding a few beep; beep; beep; beep; is also a good way to get your attention if you're not paying 100% attention to your computer all the time.

Re:Best book for this -- hands down.

[actionbastard]

The only bash scripting guide you will ever need:

http://tldp.org/guides.html

free as in beer.