{"id":398,"date":"2010-01-07T15:04:05","date_gmt":"2010-01-07T09:34:05","guid":{"rendered":"http:\/\/kedar.nitty-witty.com\/?p=398"},"modified":"2011-09-20T12:44:54","modified_gmt":"2011-09-20T12:44:54","slug":"crontab-not-working-with-dynamic-filename-rhel-linux","status":"publish","type":"post","link":"https:\/\/kedar.nitty-witty.com\/blog\/crontab-not-working-with-dynamic-filename-rhel-linux","title":{"rendered":"crontab not working with dynamic date filename – rhel linux"},"content":{"rendered":"

I have done it for so many times, setting a cronjob.
\nToday I was tring to set a simple cronjob which will output the log file with timestamp attached filename.<\/p>\n

Hourly running cron entry was:<\/p>\n

0 * * * * perl demo.pl > demo-out_`date \"+%Y-%m-%d_%H-%M\"`.log<\/code><\/p>\n

Running the same command on shell prompt was working fine. Execute permissions and path were proper.\u00a0But it kept on failing to create the proper log!!<\/p>\n

I changed the crontab as follows, added \\ before % to escape and voila!!<\/p>\n

Things worked !!<\/p>\n

0 * * * * perl test.pl > test-out_`date \"+\\%Y-\\%m-\\%d_\\%H-\\%M\"`.log<\/code><\/p>\n

A quick lesson.<\/p>\n

Good to note some of the date changers in linux for finding yesterdays and tomorrows and so on:
\ndate –date=”1 days ago”
\ndate –date=”yesterday”
\ndate –date=”next day”
\ndate –date=”-1 day”
\ndate –date=’tomorrow’
\ndate –date=’1 day’
\ndate –date=’10 day’
\ndate –date=’10 week’
\ndate –date=’10 month’
\ndate –date=’10 year’
\ndate –date=”next Friday”
\nTo escape problems you should learn to escape “special characters” – Krex<\/em>
\nP.S.:This works in real life as well \ud83d\ude09<\/p>\n","protected":false},"excerpt":{"rendered":"I have done it for so many times, setting a cronjob. Today I was tring to set a simple cronjob which will output the log file with timestamp attached filename.…\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"om_disable_all_campaigns":false,"_monsterinsights_skip_tracking":false,"_monsterinsights_sitenote_active":false,"_monsterinsights_sitenote_note":"","_monsterinsights_sitenote_category":0,"footnotes":""},"categories":[6],"tags":[219,217,59,426,218],"class_list":["post-398","post","type-post","status-publish","format-standard","category-technical","tag-date","tag-find-yesterday-in-linux","tag-linux","tag-technical","tag-tomorrow"],"aioseo_notices":[],"aioseo_head":"\n\t\t\n\t\n\t\n\t\n\t\n\t\n\t\n\t\n\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t