純粋なbashソリューション:
old=09:11
new=17:22
# feeding variables by using read and splitting with IFS
IFS=: read old_hour old_min <<< "$old"
IFS=: read hour min <<< "$new"
# convert hours to minutes
# the 10# is there to avoid errors with leading zeros
# by telling bash that we use base 10
total_old_minutes=$((10#$old_hour*60 + 10#$old_min))
total_minutes=$((10#$hour*60 + 10#$min))
echo "the difference is $((total_minutes - total_old_minutes)) minutes"
使用する別のソリューションdate
(時間/分で作業するため、日付は重要ではありません)
old=09:11
new=17:22
IFS=: read old_hour old_min <<< "$old"
IFS=: read hour min <<< "$new"
# convert the date "1970-01-01 hour:min:00" in seconds from Unix EPOCH time
sec_old=$(date -d "1970-01-01 $old_hour:$old_min:00" +%s)
sec_new=$(date -d "1970-01-01 $hour:$min:00" +%s)
echo "the difference is $(( (sec_new - sec_old) / 60)) minutes"
http://en.wikipedia.org/wiki/Unix_timeを参照