有没有一种方法可以显示或者有一个工具可以解析 crontab 表达式并以人类友好的方式显示它？
10 6 * * * sh /usr/local/crons/file_check.sh
例如，对于上面的 cron，我希望上面的 cronjob 的时间显示为
06:10 hrs
或以任何其他人类友好的方式。
目前，我决定编写一个 shell 脚本或 python 来操作输出，crontab -l以非技术人员可以理解的方式显示它，下次作业何时运行，但如果有直接的方法，那就可以了棒极了。
PS：- bash 或 python 解决方案是首选。
答案1
检查这个 github 解决方案。它的 bash 脚本。我没有尝试/测试这个解决方案。
https://github.com/inthuriel/ human-cron/blob/master/ human-cron.sh
#!/bin/bash
################################################
# bash script #
# author Mikolaj 'Metatron' Niedbala #
# displays user crontab in human readable form #
# based on `crontab` command #
# need to specify user #
# licenced GNU/ GPL #
################################################
if [[ -z $1 ]]; then
echo "Podaj uzytkownika CRON, dla ktorego wyswietlic tabele"
exit 1;
fi;
echo -e "Lista komend do wykonania dla uzytkownika $1\n"
crontab -l -u $1 | while read line
do
if [[ ! $line =~ ^\# && ! -z $line ]]; then
COMBINED_DATE=0
TIME_str=""
DATE_str=""
#explode to values
COMMAND=`echo "$line" | sed 's/^\(.\{1,8\} \)\{5\}//'`
MINUTES=`echo "$line" |cut -d" " -f1`
HOUR=`echo "$line" |cut -d" " -f2`
MONTH_DAY=`echo "$line" |cut -d" " -f3`
MONTH=`echo "$line" |cut -d" " -f4`
WEEK_DAY=`echo "$line" |cut -d" " -f5`
#command string
ECHO_str="komenda $COMMAND zostanie wykonana"
#process values
#hours
if [[ ! $HOUR =~ ^\*$ && ! -z $HOUR ]]; then
if [[ $HOUR =~ ^\*\/[0-9]{1,2}$ && ! -z $HOUR ]]; then
NUM_HOUR=`echo "$HOUR" |cut -d"/" -f2`;
HR_str="co $NUM_HOUR godzin";
elif [[ $HOUR =~ ^[0-9]{1,2}$ && ! -z $HOUR ]]; then
HR_str="o godzinie $HOUR"
COMBINED_DATE=1
elif [[ $HOUR =~ ^[0-9]{1,2}-[0-9]{1,2}$ && ! -z $HOUR ]]; then
FR_NUM_HOUR=`echo "$HOUR" |cut -d"-" -f1`;
TO_NUM_HOUR=`echo "$HOUR" |cut -d"-" -f2`;
HR_str="pomiedzy godzina $FR_NUM_HOUR a $TO_NUM_HOUR"
elif [[ $HOUR =~ ^[0-9]{1,2}-[0-9]{1,2}\/[0-9]{1,2}$ && ! -z $HOUR ]]; then
NUM_HOUR=`echo "$HOUR" |cut -d"/" -f2`;
HOUR_RANGE=`echo "$HOUR" |cut -d"/" -f1`;
FR_NUM_HOUR=`echo "$HOUR_RANGE" |cut -d"-" -f1`;
TO_NUM_HOUR=`echo "$HOUR_RANGE" |cut -d"-" -f2`;
HR_str="pomiedzy godzina $FR_NUM_HOUR a $TO_NUM_HOUR, co $NUM_HOUR godziny"
fi;
else
HR_str=""
fi;
#minutes
if [[ ! $MINUTES =~ ^\*$ && ! -z $MINUTES ]]; then
if [[ $MINUTES =~ ^\*\/[0-9]{1,2}$ && ! -z $MINUTES ]]; then
NUM_MINUTES=`echo "$MINUTES" |cut -d"/" -f2`
MIN_str="co $NUM_MINUTES minut"
elif [[ $COMBINED_DATE == 1 ]]; then
if [[ ! $MINUTES =~ ^\*$ && ! -z $MINUTES ]]; then
MIN_str="$MINUTES"
else
MIN_str="w $MINUTES minucie"
fi;
elif [[ $MINUTES =~ ^[0-9]{1,2}-[0-9]{1,2}$ && ! -z $MINUTES ]]; then
FR_NUM_MINUTES=`echo "$MINUTES" |cut -d"-" -f1`;
TO_NUM_MINUTES=`echo "$MINUTES" |cut -d"-" -f2`;
MIN_str="pomiedzy $FR_NUM_MINUTES a $TO_NUM_MINUTES minuta"
elif [[ $MINUTES =~ ^[0-9]{1,2}-[0-9]{1,2}\/[0-9]{1,2}$ && ! -z $MINUTES ]]; then
NUM_MINUTES=`echo "$MINUTES" |cut -d"/" -f2`;
MINUTES_RANGE=`echo "$MINUTES" |cut -d"/" -f1`;
FR_NUM_MINUTES=`echo "$MINUTES_RANGE" |cut -d"-" -f1`;
TO_NUM_MINUTES=`echo "$MINUTES_RANGE" |cut -d"-" -f2`;
MIN_str="pomiedzy $FR_NUM_MINUTES a $TO_NUM_MINUTES minuta, co $NUM_MINUTES minuty"
fi;
else
MIN_str=""
fi;
#day of month
if [[ ! $MONTH_DAY =~ ^\*$ && ! -z $MONTH_DAY ]]; then
if [[ $MONTH_DAY =~ ^\*\/[0-9]{1,2}$ && ! -z $MONTH_DAY ]]; then
NUM_MONTH_DAY=`echo "$MONTH_DAY" |cut -d"/" -f2`
MON_D_str="co $NUM_MONTH_DAY dni"
elif [[ $MONTH_DAY =~ ^[0-9]{1,2}$ && ! -z $MONTH_DAY ]]; then
MON_D_str="$MONTH_DAY dnia miesiaca"
elif [[ $MONTH_DAY =~ ^[0-9]{1,2}-[0-9]{1,2}$ && ! -z $MONTH_DAY ]]; then
FR_NUM_MONTH_DAY=`echo "$MONTH_DAY" |cut -d"-" -f1`;
TO_NUM_MONTH_DAY=`echo "$MONTH_DAY" |cut -d"-" -f2`;
MON_D_str="pomiedzy $FR_NUM_MONTH_DAY a $TO_NUM_MONTH_DAY dniem miesiaca"
elif [[ $MONTH_DAY =~ ^[0-9]{1,2}-[0-9]{1,2}\/[0-9]{1,2}$ && ! -z $MONTH_DAY ]]; then
NUM_MONTH_DAY=`echo "$MONTH_DAY" |cut -d"/" -f2`;
MONTH_DAY_RANGE=`echo "$MONTH_DAY" |cut -d"/" -f1`;
FR_NUM_MONTH_DAY=`echo "$MONTH_DAY_RANGE" |cut -d"-" -f1`;
TO_NUM_MONTH_DAY=`echo "$MONTH_DAY_RANGE" |cut -d"-" -f2`;
MON_D_str="pomiedzy $FR_NUM_MONTH_DAY a $TO_NUM_MONTH_DAY dniem miesiaca, co $NUM_MONTH_DAY dni"
fi;
else
MON_D_str=""
fi;
#month
if [[ ! $MONTH =~ ^\*$ && ! -z $MONTH ]]; then
if [[ $MONTH =~ ^\*\/[0-9]{1,2}$ && ! -z $MONTH ]]; then
NUM_MONTH=`echo "$MONTH" |cut -d"/" -f2`
MON_str="co $NUM_MONTH miesiecy"
elif [[ $MONTH =~ ^[0-9]{1,2}$ && ! -z $MONTH ]]; then
MON_str="w $MONTH miesiacu"
elif [[ $MONTH =~ ^[0-9]{1,2}-[0-9]{1,2}$ && ! -z $MONTH ]]; then
FR_NUM_MONTH=`echo "$MONTH" |cut -d"-" -f1`;
TO_NUM_MONTH=`echo "$MONTH" |cut -d"-" -f2`;
MON_str="pomiedzy $FR_NUM_MONTH a $TO_NUM_MONTH miesiacem"
elif [[ $MONTH =~ ^[0-9]{1,2}-[0-9]{1,2}\/[0-9]{1,2}$ && ! -z $MONTH ]]; then
NUM_MONTH=`echo "$MONTH" |cut -d"/" -f2`;
MONTH_RANGE=`echo "$MONTH" |cut -d"/" -f1`;
FR_NUM_MONTH=`echo "$MONTH_RANGE" |cut -d"-" -f1`;
TO_NUM_MONTH=`echo "$MONTH_RANGE" |cut -d"-" -f2`;
MON_str="pomiedzy $FR_NUM_MONTH a $TO_NUM_MONTH miesiacem, co $NUM_MONTH miesiecy"
fi;
else
MON_str=""
fi;
#week day
if [[ ! $WEEK_DAY =~ ^\*$ && ! -z $WEEK_DAY ]]; then
if [[ $WEEK_DAY =~ ^\*\/[0-9]{1,2}$ && ! -z $WEEK_DAY ]]; then
NUM_WEEK=`echo "$WEEK_DAY" |cut -d"/" -f2`
WEK_str="co $NUM_WEEK dni tygodnia"
elif [[ $WEEK_DAY =~ ^[0-9]{1,2}$ && ! -z $WEEK_DAY ]]; then
WEK_str="$WEEK_DAY dnia tygodnia"
elif [[ $WEEK_DAY =~ ^[0-9]{1,2}-[0-9]{1,2}$ && ! -z $WEEK_DAY ]]; then
FR_NUM_WEEK_DAY=`echo "$WEEK_DAY" |cut -d"-" -f1`;
TO_NUM_WEEK_DAY=`echo "$WEEK_DAY" |cut -d"-" -f2`;
WEK_str="pomiedzy $FR_NUM_WEEK_DAY a $TO_NUM_WEEK_DAY dniem tygodnia"
elif [[ $WEEK_DAY =~ ^[0-9]{1,2}-[0-9]{1,2}\/[0-9]{1,2}$ && ! -z $WEEK_DAY ]]; then
NUM_WEEK_DAY=`echo "$WEEK_DAY" |cut -d"/" -f2`;
WEEK_DAY_RANGE=`echo "$WEEK_DAY" |cut -d"/" -f1`;
FR_NUM_WEEK_DAY=`echo "$WEEK_DAY_RANGE" |cut -d"-" -f1`;
TO_NUM_WEEK_DAY=`echo "$WEEK_DAY_RANGE" |cut -d"-" -f2`;
MON_str="pomiedzy $FR_NUM_WEEK_DAY a $TO_NUM_WEEK_DAY dniem tygodnia, co $NUM_WEEK_DAY dni"
fi;
else
WEK_str=""
fi;
#generate string for end user
if [[ $COMBINED_DATE == 1 ]]; then
if [[ $MIN_str =~ ^[0-9]{1}$ ]]; then
MIN_str="0$MIN_str"
fi;
TIME_str="$HR_str:$MIN_str, "
else
if [[ ! -z $HR_str ]]; then
TIME_str="$HR_str, "
else
TIME_str="$TIME_str$MIN_str, "
fi;
fi;
if [[ ! -z $WEK_str || ! -z $MON_str || ! -z $MON_D_str ]]; then
if [[ ! -z $WEK_str ]]; then
DATE_str="$WEK_str, "
fi;
if [[ ! -z $MON_str ]]; then
DATE_str="$DATE_str$MON_str, "
fi;
if [[ ! -z $MON_D_str ]]; then
DATE_str="$DATE_str$MON_D_str, "
fi;
else
DATE_str="codziennie"
fi;
if [[ $DATE_str =~ ^codziennie$ ]]; then
echo "-+ $ECHO_str $DATE_str $TIME_str" | sed 's/.\{2\}$//'
else
echo "-+ $ECHO_str $TIME_str $DATE_str" | sed 's/.\{2\}$//'
fi;
echo "--"
fi;
done;
exit 0;