Shell Programming and Scripting

i want to run a script automatic in time there us problem coming while i was doing s simple test

i do in command prompt
cat > cmdfile
50 17 * * * echo "jtgtrgtrgjtrgg"
ctrl+d

then

crontab cmdfile
so this echo command should execute on 17:50

i check in /var/spool/cron/crontabs that there is a file with same content stored in crontabs i change the mode of that file to 777 so that no problem of root come betwwen it,even check it thta through crontab -l
but still at 17:50 echo command does not show up on prompt what could be the reason behind it plz help me friends

because cron output not goes the your prompt..cron output forwards to mail which defined /etc/crontab..

like this

Code:

# grep MAIL /etc/crontab
MAILTO=root

than for gud reply but how can i find out that script or command has been run or executed soar or forward the output to my prompt to check command has been run

Cron will send mail to the "MAILTO=" environment variable that is defined in your crontab. If MAILTO is not set then mail should be sent to the owner of the crontab. The /etc/crontab file should not be consulted with regard to a user's crontab.

I personally do not trust that mail is enabled properly, and so I disable cron's attempt to send mail with output by setting MAILTO to an empty string in the crontab file.

What I recommend is to redirect the output, and standard error, to a file and in your case you can check the contents of the file a few seconds after 17:50.

Code:

MAILTO=""
50 17 *  *  *  echo "foo bar" >/tmp/crontest.out 2>&1

In this case the file /tmp/crontest.out will be created and should contain the single string 'foo bar.' The fact that the file has been crated indicates that cron attempted to execute the command and any output/error messages will be saved in the file.

Setting things up this way is a matter of personal preference, but I find it much more convenient especially when more than one person is responsible for checking results of scheduled commands.