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Module: script

Patrick Ziegler edited this page Apr 2, 2022 · 42 revisions

This module executes the defined script and displays its output. You can find community-curated script modules in the polybar-scripts repository.

NOTES:
The module will wait for the exec script to finish until updating its contents. If you are launching an application, make sure you are sending it to the background by appending & after the line that executes the application.
If your script is using an infinite loop in combination with tail = true, the exec-if condition is only checked until it evaluates to true for the first time, because it is only checked before running the exec command and since the exec command never returns (because of the infinite loop), exec-if is never evaluated again, once the exec command is running. So if the exec-if condition at some point, while the infinite loop is running, would evaluate to false the script will not suddenly stop running and the module will not disappear.

To be displayed on the bar, the script's output has to be newline terminated (as most commands do). If you want that your module disappear from the bar in some cases, your output has to be created with echo "" Otherwise an outdated output is still on the bar. See #504.

Basic settings

[module/pkgupdates-available]
type = custom/script

; Available tokens:
;   %counter%
; Command to be executed (using "/bin/sh -c [command]")
exec = checkforupdates

; Conditional command that, if defined, needs to exit successfully
; before the main exec command is invoked.
; Default: ""
exec-if = pgrep -x myservice

; Set this to true for scripts that continuously produce output
; If set to 'true', everytime the script produces a new line of output, the module updates.
; Otherwise, only the first line of output is considered and all later lines are discarded.
; Default: false
tail = true

; Seconds to sleep between updates
; Default: 5 (0 if `tail = true`)
interval = 90

; Set environment variables in the 'exec' script
; New in version 3.6.0
; env-NAME = VALUE
; env-FOO = BAR

Additional formatting

; Available tags:
;   <label> (default)
format = <label>
format-background = #999
format-foreground = #000
format-padding = 4

; Format used when the `exec` command returns with a non-zero exit code 
; Only used with `tail = false`
; If not defined, format is used instead.
; Available tags:
;   <label-fail>
; New in version 3.6.0
; format-fail = <label-fail>

; Available tokens:
;   %output%
; Default: %output%
label = %output:0:15:...%

; Available tokens:
;   %output%
; Default: %output%
; New in version 3.6.0
label-fail = %output:0:15:...%

; Available tokens:
;   %counter%
;   %pid%
;
; "click-(left|middle|right)" will be executed using "/bin/sh -c [command]"
click-left = echo left %counter%
click-middle = echo middle %counter%
click-right = echo right %counter%
double-click-left = echo double left %counter%
double-click-middle = echo double middle %counter%
double-click-right = echo double right %counter%

; Available tokens:
;   %counter%
;   %pid%
;
; "scroll-(up|down)" will be executed using "/bin/sh -c [command]"
scroll-up = echo scroll up %counter%
scroll-down = echo scroll down %counter%

Examples

You can use exec-if to only display output once the defined condition is met. For example:

[module/vpn]
type = custom/script
exec = echo vpn
exec-if = pgrep -x openvpn
interval = 5
format-underline = #268bd2
format-prefix = "🖧 "
format-prefix-foreground = #5b

The %pid% token can be used to send signals to the script, allowing for multiple states. Here is an example of a date script with two states:

[module/date]
type = custom/script
exec = /path/to/date.sh
tail = true
click-left = kill -USR1 %pid%

Note: %pid% actually refers to the sh process that executes the exec command. The shell will generally relay signals to the exec command. However if the command runs in the background it won't. In those cases you can use pgrep to find the oldest child belonging to %pid% and send the signal to that (child) pid:

click-left = "kill -USR1 $(pgrep --oldest --parent %pid%)"

date.sh:

t=0
sleep_pid=0

toggle() {
    t=$(((t + 1) % 2))

    if [ "$sleep_pid" -ne 0 ]; then
        kill $sleep_pid >/dev/null 2>&1
    fi
}


trap "toggle" USR1

while true; do
    if [ $t -eq 0 ]; then
        date
    else
        date --rfc-3339=seconds
    fi
    sleep 1 &
    sleep_pid=$!
    wait
done