How do I list all cron jobs for all users?

Question

Is there a command or an existing script that will let me view all of a *NIX system's scheduled cron jobs at once? I'd like it to include all of the user crontabs, as well as /etc/crontab, and whatever's in /etc/cron.d. It would also be nice to see the specific commands run by run-parts in /etc/crontab.

Ideally, I'd like the output in a nice column form and ordered in some meaningful way.

I could then merge these listings from multiple servers to view the overall "schedule of events."

I was about to write such a script myself, but if someone's already gone to the trouble...

Answer 1

You would have to run this as root, but:

   for user in $(cut -f1 -d: /etc/passwd); do crontab -u $user -l; done

will loop over each user name listing out their crontab. The crontabs are owned by the respective users so you won't be able to see another user's crontab w/o being them or root.

Answer 2

Depends on your version of cron. Using Vixie cron on FreeBSD, I can do something like this:

(cd /var/cron/tabs && grep -vH ^# *)

if I want it more tab deliminated, I might do something like this:

(cd /var/cron/tabs && grep -vH ^# * | sed "s/:/ /")

Where that's a literal tab in the sed replacement portion.

It may be more system independent to loop through the users in /etc/passwd and do crontab -l -u $user for each of them.

Answer 3

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

Note that it shows the user, and more-or-less sorts by hour and minute so that I can see the daily schedule.

So far, I've tested it on Ubuntu, Debian, and Red Hat AS.

#!/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}"

Answer 4

Under ubuntu or debian, you can view crontab by /var/spool/cron/crontab/ and then a file for each user is in there. That's only for user specific crontab's of course.

Answer 5

Thanks Yukondude. Very useful script. I tested it on fedora 7 and works like a charm ! This script helped me to find the cause of server reboots. Good job.

Answer 6

Hello,

Thanks for this very useful script. I had some tiny problems running it on old systems (Red Hat Enterprise 3, which handle differently egrep and tabs in strings), and other systems with nothing in /etc/cron.d/ (the script then ended with an error). So here is a patch to make it work in such cases :

2a3,4
> #See:  http://stackoverflow.com/questions/134906/how-do-i-list-all-cron-jobs-for-all-users
>
27c29,30
<         match=$(echo "${line}" | egrep -o 'run-parts (-{1,2}\S+ )*\S+')
---
>         #match=$(echo "${line}" | egrep -o 'run-parts (-{1,2}\S+ )*\S+')
>         match=$(echo "${line}" | egrep -o 'run-parts.*')
51c54,57
< cat "${CRONDIR}"/* | clean_cron_lines >>"${temp}"  # */ <not a comment>
---
> sys_cron_num=$(ls /etc/cron.d | wc -l | awk '{print $1}')
> if [ "$sys_cron_num" != 0 ]; then
>       cat "${CRONDIR}"/* | clean_cron_lines >>"${temp}"  # */ <not a comment>
> fi
67c73
<     sed "1i\mi\th\td\tm\tw\tuser\tcommand" |
---
>     sed "1i\mi${tab}h${tab}d${tab}m${tab}w${tab}user${tab}command" |

I'm not really sure the changes in the first egrep are a good idea, but well, this script has been tested on RHEL3,4,5 and Debian5 without any problem. Hope this helps!

Answer 7

I like the simple one-liner answer above:

for user in $(cut -f1 -d: /etc/passwd); do crontab -u $user -l; done

But Solaris which does not have the -u flag and does not print the user it's checking, you can modify it like so:

for user in $(cut -f1 -d: /etc/passwd); do echo User:$user; crontab -l $user 2>&1 | grep -v crontab; done

You will get a list of users without the errors thrown by crontab when an account is not allowed to use cron etc. Be aware that in Solaris, roles can be in /etc/passwd too (see /etc/user_attr).

Answer 8

getent passwd | cut -d: -f1 | perl -e'while(<>){chomp;$l = `crontab -u $_ -l 2>/dev/null`;print "$_\n$l\n" if $l}'

This avoids messing with passwd directly, skips users that have no cron entries and for those who have them it prints out the username as well as their crontab.

Mostly dropping this here though so i can find it later in case i ever need to search for it again.

Answer 9

A small refinement of Kyle Burton's answer with improved output formatting:

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