Checking a command is available before use
| 1 min read
There's one final nugget in Mr Rob's ix
script that I wanted to pick out. It's not earth shattering but still useful to have seen.
At the end of the script, the URL generated from the newly created ix.io pastebin is put into the X buffer (so that it can be pasted into other X applications). This is done via the xclip
command, but xclip
is not installed everywhere, so the ix
script checks that it is available before trying to use it:
which xclip >/dev/null || exit 0
echo "$url" | xclip
This is a common pattern.
Because the use of xclip
here is right at the end of the script (by design, most likely) it's possible to abort (|| exit 0
) if xclip
isn't there. I guess an alternative, if it was necessary to run it mid-script, would be something like this:
which xclip >/dev/null && echo "$url" | xclip
Anyway, worth knowing and having seen it, right?