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- #!/bin/sh
- #
- # Returns 0 (true) if on AC power
- # 1 (false) if not on AC power
- # 255 (false) if can't tell
- #
- # Example shell script:
- # if on_ac_power; then
- # echo We're on AC power
- # else
- # echo Can't say we're on AC power
- # fi
-
- set -e
-
- # ACPI
- #
- # This algorithm is complicated by the possibility of multiple AC
- # adapters. We scan the ac_adapter/power_supply directory looking for adapters
- # that have known states. If any adapter is on-line, we return 0. If
- # no adapters are on-line but one or more are off-line, we return 1.
- #
- if /sbin/acpi_available; then
- OFF_LINE_P=no
- if [ -d /sys/class/power_supply/ ]; then
- for FN in /sys/class/power_supply/*; do
- if test -d "${FN}" && test -r "${FN}/type"; then
- type="$(cat ${FN}/type)"
- if test "x${type}" = "xMains"; then
- if [ -r "${FN}/online" ]; then
- online="$(cat ${FN}/online)"
- [ "$online" = 1 ] && exit 0
- [ "$online" = 0 ] && OFF_LINE_P=yes
- fi
- fi
- fi
- done
- elif [ -d /proc/acpi/ac_adapter ]; then
- for FN in /proc/acpi/ac_adapter/*; do
- if [ -d "${FN}" ]; then
- if [ -r "${FN}/state" ]; then
- grep --quiet on-line "${FN}/state" && exit 0
- grep --quiet off-line "${FN}/state" && OFF_LINE_P=yes
- elif [ -r "${FN}/status" ]; then
- grep --quiet on-line "${FN}/status" && exit 0
- grep --quiet off-line "${FN}/status" && OFF_LINE_P=yes
- fi
- fi
- done
- fi
- [ "${OFF_LINE_P}" = "yes" ] && exit 1
- fi
-
- # PMU
- if [ -r /proc/pmu/info ]; then
- exec awk </proc/pmu/info '
- BEGIN { FS=":"; ret = 255 }
- /^AC Power.*1$/ { ret = 0; exit }
- /^AC Power.*0$/ { ac = 1 }
- /^Battery.*/ {
- if ($2 ~/0/ && ac == 1)
- ret = 0
- else
- ret = 1
- exit }
- END { exit ret }
- '
- fi
-
- # APM
- if [ -r /proc/apm ] && /sbin/apm_available; then
- exec awk </proc/apm '
- BEGIN { ret = 255 }
- /^[0-9.a-zA-Z]* [0-9.]* 0x.. 0x../ {
- if ($4 == "0x01") { ret = 0; exit }
- else if ($4 == "0x00") { ret = 1; exit }
- }
- END { exit ret }
- '
- fi
-
- # nothing is available
- exit 255
-