proto(4)

proto -- prototype job file for at

Synopsis

/etc/cron.d/.proto

/etc/cron.d/.proto.queue

Description

When a job is submitted to at or batch, (see at (1)) the job is constructed as a shell script. As part of this process, at reads a prototype file, and uses it in the shell script. The default .proto file is:

   #ident  "@(#)adm:.proto 1.2"
   cd $d
   ulimit $l
   umask $m
   $<

Text from the prototype file is copied to the shell script file, except for special variables that are replaced by other text:

$d: is replaced by the current directory
$l: is replaced by the current file size limit (see ulimit (2))
$m: is replaced by the current umask (see umask (2))
$t: is replaced by the time at which the job should be run. (Time is expressed as seconds since January 1, 1970, 00:00 Greenwich Mean Time and is preceded by a colon.)
$<: is replaced by text read by at from the standard input (that is, the commands provided to at to be run in the job)

When this default .proto file is used, the current directory is changed to the current directory at the time at was run, the ulimit is changed to the ulimit at the time at was run, and the umask is changed to the umask at the time at was run.

If the job is submitted in queue queue, at uses the file /etc/cron.d/.proto.queue as the prototype file if it exists, otherwise it will use the file /etc/cron.d/.proto.

Files

/etc/cron.d/.proto
/etc/cron.d/.proto.queue

References

at(1), ulimit(2), umask(2)