10 More Discussions You Might Find Interesting
1. UNIX for Dummies Questions & Answers
Hi, can someone explain the differences between using the at and crontab commands. When would you use one command over the other?
TIA
Dom (1 Reply)
Discussion started by: domburf69
1 Replies
2. Shell Programming and Scripting
I have a crontab entry,but it is not working.
Can anybody help me in this regard?? (2 Replies)
Discussion started by: Sourav_Paul
2 Replies
3. UNIX for Advanced & Expert Users
Dear All
jobs are scheduled in crontab . To view this I use crontab -l . But suddenly today I am not able to see any jobs that is being scheduled in crontab. when I type crontab -l , I am seeing nothing.I am not logging through admin user(i dont have it).But I can schedule jobs through... (3 Replies)
Discussion started by: tkbharani
3 Replies
4. UNIX for Advanced & Expert Users
hi,
I run a .sh file using crontab. I need to know the path of the file . Previously when I run the file alone , i used "pwd" but now when using crontab it gives the temp directory of the file.
Is there any way I can find the absolute path of the file when i execute it ?
Regards,
Ranga (7 Replies)
Discussion started by: r_W213
7 Replies
5. Shell Programming and Scripting
Hi All,
I've a shell script which calls a Sybase stored procedure to do some functionality. I want to schedule the running of this script by crontab. I'm using Solaris 5.8. When i executed the following command
crontab -l
i got the output as
crontab: can't open your crontab file
How... (10 Replies)
Discussion started by: sumesh.abraham
10 Replies
6. UNIX for Dummies Questions & Answers
hi all
how to schedule the crontab file in unix? (2 Replies)
Discussion started by: ss4u
2 Replies
7. Shell Programming and Scripting
i have a ksh script that creates messages in a temp directory and then sends them out using the sendmail command and i'm trying to set it up to run every night with crontab.
So the basic gist of the script is
#create temp dir and messages
...
#loop through each message and send using sendmail... (3 Replies)
Discussion started by: bob122480
3 Replies
8. UNIX for Dummies Questions & Answers
How can I run "crontab" (parameters) every 6 hours on solaris machine?
Thanks (1 Reply)
Discussion started by: gen4ik
1 Replies
9. UNIX for Dummies Questions & Answers
dear all ,
does any one now how can i become sure that the crontab that i put was working successfully not by looking for thr result of the sheduled task but from a log for the crontab or something similar
and i need to check that the cron i wrote is correct
00 15 * * 0,1,2,3,6... (2 Replies)
Discussion started by: habuzahra
2 Replies
10. UNIX for Dummies Questions & Answers
Hi
I have a shell script which works fine at the command line
and does works in crontab also but does not send the output to
mail as other scripts do by default.
10 1 * * * /export/home/test/report_script
by default should send the output to mail but the script
runs OK and the output... (1 Reply)
Discussion started by: run_time_error
1 Replies
CRONTAB(1) General Commands Manual CRONTAB(1)
NAME
crontab - maintain crontab files for individual users (Vixie Cron)
SYNOPSIS
crontab [ -u user ] file
crontab [ -u user ] [ -i ] { -e | -l | -r }
DESCRIPTION
crontab is the program used to install, deinstall or list the tables used to drive the cron(8) daemon in Vixie Cron. Each user can have
their own crontab, and though these are files in /var/spool/cron/crontabs, they are not intended to be edited directly.
If the /etc/cron.allow file exists, then you must be listed (one user per line) therein in order to be allowed to use this command. If the
/etc/cron.allow file does not exist but the /etc/cron.deny file does exist, then you must not be listed in the /etc/cron.deny file in order
to use this command.
If neither of these files exists, then depending on site-dependent configuration parameters, only the super user will be allowed to use
this command, or all users will be able to use this command.
If both files exist then /etc/cron.allow takes precedence. Which means that /etc/cron.deny is not considered and your user must be listed
in /etc/cron.allow in order to be able to use the crontab.
Regardless of the existance of any of these files, the root administrative user is always allowed to setup a crontab. For standard Debian
systems, all users may use this command.
If the -u option is given, it specifies the name of the user whose crontab is to be used (when listing) or modified (when editing). If this
option is not given, crontab examines "your" crontab, i.e., the crontab of the person executing the command. Note that su(8) can confuse
crontab and that if you are running inside of su(8) you should always use the -u option for safety's sake.
The first form of this command is used to install a new crontab from some named file or standard input if the pseudo-filename ``-'' is
given.
The -l option causes the current crontab to be displayed on standard output. See the note under DEBIAN SPECIFIC below.
The -r option causes the current crontab to be removed.
The -e option is used to edit the current crontab using the editor specified by the VISUAL or EDITOR environment variables. After you exit
from the editor, the modified crontab will be installed automatically. If neither of the environment variables is defined, then the default
editor /usr/bin/editor is used.
The -i option modifies the -r option to prompt the user for a 'y/Y' response before actually removing the crontab.
DEBIAN SPECIFIC
The "out-of-the-box" behaviour for crontab -l is to display the three line "DO NOT EDIT THIS FILE" header that is placed at the beginning
of the crontab when it is installed. The problem is that it makes the sequence
crontab -l | crontab -
non-idempotent -- you keep adding copies of the header. This causes pain to scripts that use sed to edit a crontab. Therefore, the default
behaviour of the -l option has been changed to not output such header. You may obtain the original behaviour by setting the environment
variable CRONTAB_NOHEADER to 'N', which will cause the crontab -l command to emit the extraneous header.
SEE ALSO
crontab(5), cron(8)
FILES
/etc/cron.allow
/etc/cron.deny
/var/spool/cron/crontabs
There is one file for each user's crontab under the /var/spool/cron/crontabs directory. Users are not allowed to edit the files under that
directory directly to ensure that only users allowed by the system to run periodic tasks can add them, and only syntactically correct
crontabs will be written there. This is enforced by having the directory writable only by the crontab group and configuring crontab com-
mand with the setgid bid set for that specific group.
STANDARDS
The crontab command conforms to IEEE Std1003.2-1992 (``POSIX''). This new command syntax differs from previous versions of Vixie Cron, as
well as from the classic SVR3 syntax.
DIAGNOSTICS
A fairly informative usage message appears if you run it with a bad command line.
cron requires that each entry in a crontab end in a newline character. If the last entry in a crontab is missing the newline, cron will
consider the crontab (at least partially) broken and refuse to install it.
AUTHOR
Paul Vixie <paul@vix.com>
4th Berkeley Distribution 19 April 2010 CRONTAB(1)