(03/16/2011 03:54 AM), Barrie Stott wrote: > The script that follows is a cut down version of one that came from elsewhere. > > #!/bin/bash > > cp /tmp/x.html /tmp/$$.html > ls /tmp/$$.html > [ "$DISPLAY" ] && open /tmp/$$.html > ls /tmp/$$.html > rm -f /tmp/$$.html > > I'm on an Imac with OS X 10.6.6. If I run the script as it stands, the open > tries to open /tmp/$$.html in a new tab in the Safari browser and fails with > the message: No file exists at the address “/tmp/13551.html”. The terminal > output is the following pair of lines, which suggest that the file is still > around after open failed: > > /tmp/13551.html > /tmp/13551.html > > If I comment out the final 'rm' line and run it again, I get what I want > displayed (and a similar pair of lines on the terminal) but unfortunately the > temporary file is left lying around. > > My two questions are: > Why?
>From the symptoms you describe, it seems extremly likely that the "open" command simply sends a message to Safari and exits. This exit may very well occur before Safari actually gets a chance to obey the message. This then produces a race: will Safari open the file before bash gets to and executes the "rm" command, or...? > How can I change the script so that I can both view the file and have it > removed? That depends on Safari, really. There's no way for a script to know whether Safari has opened the tab, unless Safari provides a means for knowing it. Perhaps open has an option that lets it block until Safari acknowledges having opened the file? If not, then probably the best you can do is a heuristic: sleep a couple seconds after evaluating "open", and then continue on. -- Good luck! Micah J. Cowan http://micah.cowan.name/
