Linux at job delete

at (1) — Linux Manuals

at: queue, examine or delete jobs for later execution

Command to display at manual in Linux: $ man 1 at

NAME

SYNOPSIS

at [-V] [-q queue] [-f file] [-mMlv] timespec.
at [-V] [-q queue] [-f file] [-mMkv] [-t time]
at -c job [job. ]
atq [-V] [-q queue]
at [-rd] job [job. ]
atrm [-V] job [job. ]
batch
at -b

DESCRIPTION

at and batch read commands from standard input or a specified file which are to be executed at a later time, using /bin/sh. at executes commands at a specified time. atq lists the user’s pending jobs, unless the user is the superuser; in that case, everybody’s jobs are listed. The format of the output lines (one for each job) is: Job number, date, hour, queue, and username. atrm deletes jobs, identified by their job number. batch executes commands when system load levels permit; in other words, when the load average drops below 0.8, or the value specified in the invocation of atd.

At allows fairly complex time specifications, extending the POSIX.2 standard. It accepts times of the form HH:MM to run a job at a specific time of day. (If that time is already past, the next day is assumed.) You may also specify midnight, noon, or teatime (4pm) and you can have a time-of-day suffixed with AM or PM for running in the morning or the evening. You can also say what day the job will be run, by giving a date in the form month-name day with an optional year, or giving a date of the form MMDD[CC]YY, MM/DD/[CC]YY, DD.MM.[CC]YY or [CC]YY—MM—DD. The specification of a date must follow the specification of the time of day. You can also give times like now + count time-units, where the time-units can be minutes, hours, days, or weeks and you can tell at to run the job today by suffixing the time with today and to run the job tomorrow by suffixing the time with tomorrow.

For example, to run a job at 4pm three days from now, you would do at 4pm + 3 days, to run a job at 10:00am on July 31, you would do at 10am Jul 31 and to run a job at 1am tomorrow, you would do at 1am tomorrow.

The definition of the time specification can be found in /usr/share/doc/at-3.1.13/timespec.

For both at and batch, commands are read from standard input or the file specified with the -f option and executed. The working directory, the environment (except for the variables BASH_VERSINFO, DISPLAY, EUID, GROUPS, SHELLOPTS, TERM, UID, and _) and the umask are retained from the time of invocation.

As at is currently implemented as a setuid program, other environment variables (e.g. LD_LIBRARY_PATH or LD_PRELOAD) are also not exported. This may change in the future. As a workaround, set these variables explicitly in your job.

An at — or batch — command invoked from a su(1) shell will retain the current userid. The user will be mailed standard error and standard output from his commands, if any. Mail will be sent using the command /usr/sbin/sendmail. If at is executed from a su(1) shell, the owner of the login shell will receive the mail.

The superuser may use these commands in any case. For other users, permission to use at is determined by the files /etc/at.allow and /etc/at.deny. See at.allow(5) for details.

OPTIONS

-V prints the version number to standard error and exit successfully. -q queue uses the specified queue. A queue designation consists of a single letter; valid queue designations range from a to z and A to Z. The a queue is the default for at and the b queue for batch. Queues with higher letters run with increased niceness. The special queue » ezoic-autoinsert-ad ezoic-long_content»> -m Send mail to the user when the job has completed even if there was no output. -M Never send mail to the user. -f file Reads the job from file rather than standard input. -t time run the job at time, given in the format [[CC]YY]MMDDhhmm[.ss] -l Is an alias for atq. -r Is an alias for atrm. -d Is an alias for atrm. -b is an alias for batch. -v Shows the time the job will be executed before reading the job.

Times displayed will be in the format «Thu Feb 20 14:50:00 1997».

-c cats the jobs listed on the command line to standard output.

FILES

/var/spool/at
/var/spool/at/spool
/proc/loadavg
/var/run/utmp
/etc/at.allow
/etc/at.deny

BUGS

The correct operation of batch for Linux depends on the presence of a proc— type directory mounted on /proc.

If the file /var/run/utmp is not available or corrupted, or if the user is not logged on at the time at is invoked, the mail is sent to the userid found in the environment variable LOGNAME. If that is undefined or empty, the current userid is assumed.

At and batch as presently implemented are not suitable when users are competing for resources. If this is the case for your site, you might want to consider another batch system, such as nqs.

AUTHOR

SEE ALSO

Pages related to at

• at (1p) — execute commands at a later time
• at (3) — 1-D array used in linear algebra.
• at (5) — determine who can submit jobs via at or batch
• atasm (1) — assembler targeted for the 6502 CPU with Atari-specific features
• aterm (1)
• atktopbm (1) — convert Andrew Toolkit raster object to portable bitmap
• atobm (1) — bitmap editor and converter utilities for the X Window System
• atomic-cluster (1) — Manage cluster hosts
• atomic-containers (1) — operations on containers
• atomic-diff (1) — show the differences between two images|containers RPMs
• atomic-host (1) — Manage Atomic Host Commands
• atomic-images (1) — operations on container images
• abicompat (1) — check ABI compatibility

Index

SEE ALSO

Pages related to at

• at (1p) — execute commands at a later time
• at (3) — 1-D array used in linear algebra.
• at (5) — determine who can submit jobs via at or batch
• atasm (1) — assembler targeted for the 6502 CPU with Atari-specific features
• aterm (1)
• atktopbm (1) — convert Andrew Toolkit raster object to portable bitmap
• atobm (1) — bitmap editor and converter utilities for the X Window System
• atomic-cluster (1) — Manage cluster hosts
• atomic-containers (1) — operations on containers
• atomic-diff (1) — show the differences between two images|containers RPMs
• atomic-host (1) — Manage Atomic Host Commands
• atomic-images (1) — operations on container images
• abicompat (1) — check ABI compatibility

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at(1) — Linux man page

lists the user’s pending jobs, unless the user is the superuser; in that case, everybody’s jobs are listed. The format of the output lines (one for each job) is: Job number, date, hour, queue, and username.

deletes jobs, identified by their job number.

executes commands when system load levels permit; in other words, when the load average drops below 0.8, or the value specified in the invocation of atd. At allows fairly complex time specifications, extending the POSIX.2 standard. It accepts times of the form HH:MM to run a job at a specific time of day. (If that time is already past, the next day is assumed.) You may also specify midnight, noon, or teatime (4pm) and you can have a time-of-day suffixed with AM or PM for running in the morning or the evening. You can also say what day the job will be run, by giving a date in the form month-name day with an optional year, or giving a date of the form MMDDYY or MM/DD/YY or DD.MM.YY or YYYY-MM-DD. The specification of a date must follow the specification of the time of day. You can also give times like now + count time-units, where the time-units can be minutes, hours, days, or weeks and you can tell at to run the job today by suffixing the time with today and to run the job tomorrow by suffixing the time with tomorrow.

For example, to run a job at 4pm three days from now, you would do at 4pm + 3 days, to run a job at 10:00am on July 31, you would do at 10am Jul 31 and to run a job at 1am tomorrow, you would do at 1am tomorrow.

The exact definition of the time specification can be found in /usr/share/doc/at-3.1.10/timespec.

For both at and batch, commands are read from standard input or the file specified with the -f option and executed. The working directory, the environment (except for the variables TERM, DISPLAY and _) and the umask are retained from the time of invocation. An at — or batch — command invoked from a su(1) shell will retain the current userid. The user will be mailed standard error and standard output from his commands, if any. Mail will be sent using the command /usr/sbin/sendmail. If at is executed from a su(1) shell, the owner of the login shell will receive the mail.

The superuser may use these commands in any case. For other users, permission to use at is determined by the files /etc/at.allow and /etc/at.deny.

If the file /etc/at.allow exists, only usernames mentioned in it are allowed to use at.

If /etc/at.allow does not exist, /etc/at.deny is checked, every username not mentioned in it is then allowed to use at.

If neither exists, only the superuser is allowed use of at.

An empty /etc/at.deny means that every user is allowed use these commands, this is the default configuration.

Options

prints the version number to standard error. -q queue uses the specified queue. A queue designation consists of a single letter; valid queue designations range from a to z. and A to Z. The a queue is the default for at and the b queue for batch. Queues with higher letters run with increased niceness. The special queue » Thu Feb 20 14:50:00 1997″. -c

cats the jobs listed on the command line to standard output. -t time_arg Submit the job to be run at the time specified by the time_arg option argument, which must have the same format as specified for the touch(1) utility’s -t time option argument ([[CC]YY]MMDDhhmm).

Environment

The value of the SHELL environment variable at the time of at invocation will determine which shell is used to execute the at job commands. If SHELL is unset when at is invoked, the user’s login shell will be used; otherwise, if SHELL is set when at is invoked, it must contain the path of a shell interpreter executable that will be used to run the commands at the specified time. at will record the values of environment variables present at time of at invocation. When the commands are run at the specified time, at will restore these variables to their recorded values . These variables are excluded from this processing and are never set by at when the commands are run :
TERM, DISPLAY, SHELLOPTS, _, PPID, BASH_VERSINFO, EUID, UID, GROUPS.
If the user submitting the at job is not the super-user, variables that alter the behaviour of the loader ld.so(8), such as LD_LIBRARY_PATH , cannot be recorded and restored by at .

Files

/var/spool/at
/var/spool/at/spool
/proc/loadavg
/var/run/utmp
/etc/at.allow
/etc/at.deny

See Also

cron(1), nice(1), sh(1), umask(2), atd(8).

Bugs

The correct operation of batch for Linux depends on the presence of a proc— type directory mounted on /proc.

If the file /var/run/utmp is not available or corrupted, or if the user is not logged on at the time at is invoked, the mail is sent to the userid found in the environment variable LOGNAME. If that is undefined or empty, the current userid is assumed.

At and batch as presently implemented are not suitable when users are competing for resources. If this is the case for your site, you might want to consider another batch system, such as nqs.

Author

At was mostly written by Thomas Koenig, ig25@rz.uni-karlsruhe.de.

Источник

Remove all `at` jobs

I know that to remove a scheduled at job I have to use atrm «numjob1 numjob2» , but is there an easy way to do that for all the jobs?

6 Answers 6

You can run this command to remove all the jobs at the atq

 for i in `atq | awk ''`;do atrm $i;done 

variation on this answer at -l | awk ‘‘ | xargs atrm

You could do something like this:

for i in $(atq | cut -f 1); do atrm $i; done 

This seems to me a short line:

For more AIX 6 systems you can simply do:

Here is my xargs version that avoids braces and is hopefully intuitive:

You can also grep specific jobs by timestamp/userid and then remove them:

atq | grep "2018-10-22 16:" | cut -f 1 | xargs atrm 

I had more than 58k jobs in the atd (someone rebooted the server and for some reason atd service not started). Removing the jobs using atrm is very painful for very high queue.

I stopped atd and deleted all dirs from /var/spool/atjobs and files from /var/spool/atspool . For me it worked.

rm -rf /var/spool/atjobs/* ; rm /var/spool/atspool/* 

You never say anything about starting up atd again, and whether that was successful, nor do you mention what Unix this would be an adequate solution for. How did you make sure that other users’ jobs were not deleted?

Ok! Sorry! Need to start atd after the process. My solution is for «SUSE Linux Enterprise Server 12». But I think it can use in other distributions. I found the information of directories in «man». In my situation, only root is using atd, then removing the files was safe.

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