1.5 KiB
Reading files
NOTE: The following information only applies to spmenu 1.1 and later.
spmenu is designed to read files. Most of the time it reads standard input which is also a file (/dev/stdin which is a symlink to /proc/self/fd/0 on systems using the Linux kernel). You don't necessarily have to read standard input or stdin though, as of spmenu 1.1 you can read any file you want.
Reading from a file has benefits. When reading from standard input the entries are only loaded once. When reading from a file however, if the file is modified the new entries will be loaded and displayed on the next X11 event.
Reading from a file
To read from any file you want, simply run spmenu with the -lf
or --list-file
argument. You can actually read from standard output using --list-file
as well, by using stdin | spmenu --list-file /dev/stdin
, but there is really no reason to do this as reading standard input is the default spmenu behavior anyway.
For instance, spmenu --list-file /tmp/file
would load entries from /tmp/file.
Real world use case
Let's say we want to display the time and update it every second. In that case we can write a script like this:
#!/bin/sh
func() {
while true; do
date > /tmp/date-file
sleep 1
done
}
func &
spmenu -lf /tmp/date-file -p "The time is:"
speedwm-extras' speedwm-btctrl uses this feature to load Bluetooth entries every 5 seconds.