你可以写所有用户列表:

sudo crontab -u userName -l

,

你也可以去

cd /etc/cron.daily/
ls -l
cat filename

这个文件将列出时间表

cd /etc/cron.d/
ls -l
cat filename

向yukondude表示歉意和感谢。

我已经试着总结了时间设置以便于阅读，尽管这不是一个完美的工作，而且我不会碰“每周五”或“只有周一”的东西。

这是版本10 -现在:

runs much much faster has optional progress characters so you could improve the speed further. uses a divider line to separate header and output. outputs in a compact format when all timing intervals uencountered can be summarised. Accepts Jan...Dec descriptors for months-of-the-year Accepts Mon...Sun descriptors for days-of-the-week tries to handle debian-style dummying-up of anacron when it is missing tries to deal with crontab lines which run a file after pre-testing executability using "[ -x ... ]" tries to deal with crontab lines which run a file after pre-testing executability using "command -v" allows the use of interval spans and lists. supports run-parts usage in user-specific /var/spool crontab files.

我现在在这里发布完整的脚本。

https://gist.github.com/myshkin-uk/d667116d3e2d689f23f18f6cd3c71107

如果您使用NIS检查集群，查看用户是否有crontab条目的唯一方法是根据Matt的回答/var/spool/ crontab .

grep -v "#" -R  /var/spool/cron/tabs

这个脚本将Crontab输出到一个文件中，并列出所有确认没有Crontab条目的用户:

for user in $(cut -f1 -d: /etc/passwd); do 
  echo $user >> crontab.bak
  echo "" >> crontab.bak
  crontab -u $user -l >> crontab.bak 2>> > crontab.bak
done

I ended up writing a script (I'm trying to teach myself the finer points of bash scripting, so that's why you don't see something like Perl here). It's not exactly a simple affair, but it does most of what I need. It uses Kyle's suggestion for looking up individual users' crontabs, but also deals with /etc/crontab (including the scripts launched by run-parts in /etc/cron.hourly, /etc/cron.daily, etc.) and the jobs in the /etc/cron.d directory. It takes all of those and merges them into a display something like the following:

mi     h    d  m  w  user      command
09,39  *    *  *  *  root      [ -d /var/lib/php5 ] && find /var/lib/php5/ -type f -cmin +$(/usr/lib/php5/maxlifetime) -print0 | xargs -r -0 rm
47     */8  *  *  *  root      rsync -axE --delete --ignore-errors / /mirror/ >/dev/null
17     1    *  *  *  root      /etc/cron.daily/apt
17     1    *  *  *  root      /etc/cron.daily/aptitude
17     1    *  *  *  root      /etc/cron.daily/find
17     1    *  *  *  root      /etc/cron.daily/logrotate
17     1    *  *  *  root      /etc/cron.daily/man-db
17     1    *  *  *  root      /etc/cron.daily/ntp
17     1    *  *  *  root      /etc/cron.daily/standard
17     1    *  *  *  root      /etc/cron.daily/sysklogd
27     2    *  *  7  root      /etc/cron.weekly/man-db
27     2    *  *  7  root      /etc/cron.weekly/sysklogd
13     3    *  *  *  archiver  /usr/local/bin/offsite-backup 2>&1
32     3    1  *  *  root      /etc/cron.monthly/standard
36     4    *  *  *  yukon     /home/yukon/bin/do-daily-stuff
5      5    *  *  *  archiver  /usr/local/bin/update-logs >/dev/null

请注意，它显示了用户，并或多或少地按小时和分钟排序，以便我可以看到每天的日程安排。

到目前为止，我已经在Ubuntu、Debian和Red Hat AS上测试了它。

#!/bin/bash

# System-wide crontab file and cron job directory. Change these for your system.
CRONTAB='/etc/crontab'
CRONDIR='/etc/cron.d'

# Single tab character. Annoyingly necessary.
tab=$(echo -en "\t")

# Given a stream of crontab lines, exclude non-cron job lines, replace
# whitespace characters with a single space, and remove any spaces from the
# beginning of each line.
function clean_cron_lines() {
    while read line ; do
        echo "${line}" |
            egrep --invert-match '^($|\s*#|\s*[[:alnum:]_]+=)' |
            sed --regexp-extended "s/\s+/ /g" |
            sed --regexp-extended "s/^ //"
    done;
}

# Given a stream of cleaned crontab lines, echo any that don't include the
# run-parts command, and for those that do, show each job file in the run-parts
# directory as if it were scheduled explicitly.
function lookup_run_parts() {
    while read line ; do
        match=$(echo "${line}" | egrep -o 'run-parts (-{1,2}\S+ )*\S+')

        if [[ -z "${match}" ]] ; then
            echo "${line}"
        else
            cron_fields=$(echo "${line}" | cut -f1-6 -d' ')
            cron_job_dir=$(echo  "${match}" | awk '{print $NF}')

            if [[ -d "${cron_job_dir}" ]] ; then
                for cron_job_file in "${cron_job_dir}"/* ; do  # */ <not a comment>
                    [[ -f "${cron_job_file}" ]] && echo "${cron_fields} ${cron_job_file}"
                done
            fi
        fi
    done;
}

# Temporary file for crontab lines.
temp=$(mktemp) || exit 1

# Add all of the jobs from the system-wide crontab file.
cat "${CRONTAB}" | clean_cron_lines | lookup_run_parts >"${temp}" 

# Add all of the jobs from the system-wide cron directory.
cat "${CRONDIR}"/* | clean_cron_lines >>"${temp}"  # */ <not a comment>

# Add each user's crontab (if it exists). Insert the user's name between the
# five time fields and the command.
while read user ; do
    crontab -l -u "${user}" 2>/dev/null |
        clean_cron_lines |
        sed --regexp-extended "s/^((\S+ +){5})(.+)$/\1${user} \3/" >>"${temp}"
done < <(cut --fields=1 --delimiter=: /etc/passwd)

# Output the collected crontab lines. Replace the single spaces between the
# fields with tab characters, sort the lines by hour and minute, insert the
# header line, and format the results as a table.
cat "${temp}" |
    sed --regexp-extended "s/^(\S+) +(\S+) +(\S+) +(\S+) +(\S+) +(\S+) +(.*)$/\1\t\2\t\3\t\4\t\5\t\6\t\7/" |
    sort --numeric-sort --field-separator="${tab}" --key=2,1 |
    sed "1i\mi\th\td\tm\tw\tuser\tcommand" |
    column -s"${tab}" -t

rm --force "${temp}"

对Kyle Burton的回答稍加改进，改进了输出格式:

#!/bin/bash
for user in $(cut -f1 -d: /etc/passwd)
do echo $user && crontab -u $user -l
echo " "
done