34 lines
1.6 KiB
Markdown
34 lines
1.6 KiB
Markdown
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](https://git.speedie.site/speedie/speedwm-extras)' speedwm-btctrl uses this feature to load Bluetooth entries every 5 seconds. There are more example scripts that also read from file in the `scripts/examples` directory.
|