Un archivo de texto que posee una lista con todos los scripts a ejecutar. Generalmente cada usuario del sistema posee su propio fichero Crontab. Se considera que el ubicado en la carpeta etc pertenece al usuario root.


# Edit this file to introduce tasks to be run by cron.
# Each task to run has to be defined through a single line
# indicating with different fields when the task will be run
# and what command to run for the task
# To define the time you can provide concrete values for
# minute (m), hour (h), day of month (dom), month (mon),
# and day of week (dow) or use '*' in these fields (for 'any').#
# Notice that tasks will be started based on the cron's system
# daemon's notion of time and timezones.
# Output of the crontab jobs (including errors) is sent through
# email to the user the crontab file belongs to (unless redirected).
# For example, you can run a backup of all your user accounts
# at 5 a.m every week with:
# 0 5 * * 1 tar -zcf /var/backups/home.tgz /home/
# For more information see the manual pages of crontab(5) and cron(8)
# m h  dom mon dow   command
1 */1 * * *  /bin/bash /opt/laRioja/procesar.sh
5  0  * * *   root    /opt/reinicioTomcat/reiniciatomcat.sh

Comandos crontab:

crontab -l => ver configuración de crontab
crontab -e => modificar configuración de crontab
crontab archivo => cambiar archivo configuración de crontab
crontab -d => borrar crontab configurado