What is `-p` used for `cron`?

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In cron's manpage (cronie)

-p Allows Cron to accept any user set crontables.

I learned that cron daemon will implicitly search for and run the cron jobs defined in /etc/crontab, /etc/cron.d/* and /var/spool/cron/cronstabs/*.

What is -p used for?

Is it to explicitly tell cron to search for and run the cron jobs defined in a crontab file which is stored in some place other than those mentioned above?

Or is it to copy a crontab file stored in some place other than those mentioned above to one of the places mentioned above?

Does the cron on Debian or its derivatives have -p option? I don't find -p on the manpage of cron on Ubuntu.

Thanks.

edited 3 hours ago

asked 3 hours ago

Tim

24.5k69239426

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up vote
2
down vote

favorite

In cron's manpage (cronie)

-p Allows Cron to accept any user set crontables.

I learned that cron daemon will implicitly search for and run the cron jobs defined in /etc/crontab, /etc/cron.d/* and /var/spool/cron/cronstabs/*.

What is -p used for?

Is it to explicitly tell cron to search for and run the cron jobs defined in a crontab file which is stored in some place other than those mentioned above?

Or is it to copy a crontab file stored in some place other than those mentioned above to one of the places mentioned above?

Does the cron on Debian or its derivatives have -p option? I don't find -p on the manpage of cron on Ubuntu.

Thanks.

edited 3 hours ago

asked 3 hours ago

Tim

24.5k69239426

add a commentÂ |Â

up vote
2
down vote

favorite

In cron's manpage (cronie)

-p Allows Cron to accept any user set crontables.

I learned that cron daemon will implicitly search for and run the cron jobs defined in /etc/crontab, /etc/cron.d/* and /var/spool/cron/cronstabs/*.

What is -p used for?

Is it to explicitly tell cron to search for and run the cron jobs defined in a crontab file which is stored in some place other than those mentioned above?

Or is it to copy a crontab file stored in some place other than those mentioned above to one of the places mentioned above?

Does the cron on Debian or its derivatives have -p option? I don't find -p on the manpage of cron on Ubuntu.

Thanks.

edited 3 hours ago

asked 3 hours ago

Tim

24.5k69239426

In cron's manpage (cronie)

-p Allows Cron to accept any user set crontables.

I learned that cron daemon will implicitly search for and run the cron jobs defined in /etc/crontab, /etc/cron.d/* and /var/spool/cron/cronstabs/*.

What is -p used for?

Is it to explicitly tell cron to search for and run the cron jobs defined in a crontab file which is stored in some place other than those mentioned above?

Or is it to copy a crontab file stored in some place other than those mentioned above to one of the places mentioned above?

Does the cron on Debian or its derivatives have -p option? I don't find -p on the manpage of cron on Ubuntu.

Thanks.

cron

edited 3 hours ago

asked 3 hours ago

Tim

24.5k69239426

edited 3 hours ago

asked 3 hours ago

Tim

24.5k69239426

edited 3 hours ago

asked 3 hours ago

Tim

24.5k69239426

asked 3 hours ago

Tim

24.5k69239426

asked 3 hours ago

Tim

24.5k69239426

add a commentÂ |Â

2 Answers
2

active

oldest

votes

up vote
3
down vote

The CAVEATS section of the cronie's cron(8) man page says (emphasis mine):

All crontab files have to be regular files or symlinks to regular
files, they must not be executable or writable for anyone else but
the owner. This requirement can be overridden by using the -p option
on the crond command line.

So it is in fact documented on the man page, although not in the most obvious location.

answered 3 hours ago

telcoM

13.6k11742

Thanks. Can the file argument to -p be anywhere in any filesystem, or must it be in either`/etc/cron.d/ or /varspool/cron/crontabs/?
â€“Â Tim
2 hours ago

1

The -p option takes no "file argument" and has no effect as to where the cron daemon looks for crontab files; it just switches the ownership/permission/filetype checks off. The cron daemon will still look for crontabs in three places: the file /etc/crontab, any files in directory /etc/cron.d/, and any files in directory /var/spool/cron/. These locations can apparently only be changed by modifying the cron source code.
â€“Â telcoM
2 hours ago

add a commentÂ |Â

up vote
2
down vote

Good question. It doesn't appear to be documented within the man page. Looking at the source, we see -p sets PermitAnyCrontab, see https://github.com/cronie-crond/cronie/blob/master/src/cron.c#L703

 case 'p':
 PermitAnyCrontab = 1;

Which in turn gets used https://github.com/cronie-crond/cronie/blob/40b7164227a17058afb4f3d837ebb3263943e2e6/src/database.c#L89

Makes cron less fussy about the crontab file's state (can be a non-regular file, can have a different owner, can have a mode that's not 400, can have a link count other than 1).

if (PermitAnyCrontab == 0)

While it's clearly present within cronie, such a feature is not present in Vixie Cron (https://github.com/svagner/vixie-cron)

edited 3 hours ago

answered 3 hours ago

steve

13.3k22251

Thanks. Can such a crontab file specified by -p be stored anywhere? Must it be user-specific crontab file, not system crontab file?
â€“Â Tim
3 hours ago

It can be a symlink to elsewhere. All it does is bypass a safeguards / checks really. Note it's crond itself, not crontab.
â€“Â steve
3 hours ago

Do you mean the file argument to -p must still be in either`/etc/cron.d/ or /varspool/cron/crontabs/, not anywhere in any filesystem?
â€“Â Tim
3 hours ago

add a commentÂ |Â

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2 Answers
2

active

oldest

votes

2 Answers
2

active

oldest

votes

up vote
3
down vote

The CAVEATS section of the cronie's cron(8) man page says (emphasis mine):

All crontab files have to be regular files or symlinks to regular
files, they must not be executable or writable for anyone else but
the owner. This requirement can be overridden by using the -p option
on the crond command line.

So it is in fact documented on the man page, although not in the most obvious location.

answered 3 hours ago

telcoM

13.6k11742

Thanks. Can the file argument to -p be anywhere in any filesystem, or must it be in either`/etc/cron.d/ or /varspool/cron/crontabs/?
â€“Â Tim
2 hours ago

1

The -p option takes no "file argument" and has no effect as to where the cron daemon looks for crontab files; it just switches the ownership/permission/filetype checks off. The cron daemon will still look for crontabs in three places: the file /etc/crontab, any files in directory /etc/cron.d/, and any files in directory /var/spool/cron/. These locations can apparently only be changed by modifying the cron source code.
â€“Â telcoM
2 hours ago

add a commentÂ |Â

up vote
3
down vote

The CAVEATS section of the cronie's cron(8) man page says (emphasis mine):

All crontab files have to be regular files or symlinks to regular
files, they must not be executable or writable for anyone else but
the owner. This requirement can be overridden by using the -p option
on the crond command line.

So it is in fact documented on the man page, although not in the most obvious location.

answered 3 hours ago

telcoM

13.6k11742

Thanks. Can the file argument to -p be anywhere in any filesystem, or must it be in either`/etc/cron.d/ or /varspool/cron/crontabs/?
â€“Â Tim
2 hours ago

1

The -p option takes no "file argument" and has no effect as to where the cron daemon looks for crontab files; it just switches the ownership/permission/filetype checks off. The cron daemon will still look for crontabs in three places: the file /etc/crontab, any files in directory /etc/cron.d/, and any files in directory /var/spool/cron/. These locations can apparently only be changed by modifying the cron source code.
â€“Â telcoM
2 hours ago

add a commentÂ |Â

up vote
3
down vote

The CAVEATS section of the cronie's cron(8) man page says (emphasis mine):

All crontab files have to be regular files or symlinks to regular
files, they must not be executable or writable for anyone else but
the owner. This requirement can be overridden by using the -p option
on the crond command line.

So it is in fact documented on the man page, although not in the most obvious location.

answered 3 hours ago

telcoM

13.6k11742

The CAVEATS section of the cronie's cron(8) man page says (emphasis mine):

All crontab files have to be regular files or symlinks to regular
files, they must not be executable or writable for anyone else but
the owner. This requirement can be overridden by using the -p option
on the crond command line.

So it is in fact documented on the man page, although not in the most obvious location.

answered 3 hours ago

telcoM

13.6k11742

answered 3 hours ago

telcoM

13.6k11742

answered 3 hours ago

telcoM

13.6k11742

answered 3 hours ago

telcoM

13.6k11742

Thanks. Can the file argument to -p be anywhere in any filesystem, or must it be in either`/etc/cron.d/ or /varspool/cron/crontabs/?
â€“Â Tim
2 hours ago

1

The -p option takes no "file argument" and has no effect as to where the cron daemon looks for crontab files; it just switches the ownership/permission/filetype checks off. The cron daemon will still look for crontabs in three places: the file /etc/crontab, any files in directory /etc/cron.d/, and any files in directory /var/spool/cron/. These locations can apparently only be changed by modifying the cron source code.
â€“Â telcoM
2 hours ago

add a commentÂ |Â

Thanks. Can the file argument to -p be anywhere in any filesystem, or must it be in either`/etc/cron.d/ or /varspool/cron/crontabs/?
â€“Â Tim
2 hours ago

1

The -p option takes no "file argument" and has no effect as to where the cron daemon looks for crontab files; it just switches the ownership/permission/filetype checks off. The cron daemon will still look for crontabs in three places: the file /etc/crontab, any files in directory /etc/cron.d/, and any files in directory /var/spool/cron/. These locations can apparently only be changed by modifying the cron source code.
â€“Â telcoM
2 hours ago

Thanks. Can the file argument to -p be anywhere in any filesystem, or must it be in either`/etc/cron.d/ or /varspool/cron/crontabs/?
â€“Â Tim
2 hours ago

The -p option takes no "file argument" and has no effect as to where the cron daemon looks for crontab files; it just switches the ownership/permission/filetype checks off. The cron daemon will still look for crontabs in three places: the file /etc/crontab, any files in directory /etc/cron.d/, and any files in directory /var/spool/cron/. These locations can apparently only be changed by modifying the cron source code.
â€“Â telcoM
2 hours ago

add a commentÂ |Â

up vote
2
down vote

Good question. It doesn't appear to be documented within the man page. Looking at the source, we see -p sets PermitAnyCrontab, see https://github.com/cronie-crond/cronie/blob/master/src/cron.c#L703

 case 'p':
 PermitAnyCrontab = 1;

Which in turn gets used https://github.com/cronie-crond/cronie/blob/40b7164227a17058afb4f3d837ebb3263943e2e6/src/database.c#L89

Makes cron less fussy about the crontab file's state (can be a non-regular file, can have a different owner, can have a mode that's not 400, can have a link count other than 1).

if (PermitAnyCrontab == 0)

While it's clearly present within cronie, such a feature is not present in Vixie Cron (https://github.com/svagner/vixie-cron)

edited 3 hours ago

answered 3 hours ago

steve

13.3k22251

Thanks. Can such a crontab file specified by -p be stored anywhere? Must it be user-specific crontab file, not system crontab file?
â€“Â Tim
3 hours ago

It can be a symlink to elsewhere. All it does is bypass a safeguards / checks really. Note it's crond itself, not crontab.
â€“Â steve
3 hours ago

Do you mean the file argument to -p must still be in either`/etc/cron.d/ or /varspool/cron/crontabs/, not anywhere in any filesystem?
â€“Â Tim
3 hours ago

add a commentÂ |Â

up vote
2
down vote

Good question. It doesn't appear to be documented within the man page. Looking at the source, we see -p sets PermitAnyCrontab, see https://github.com/cronie-crond/cronie/blob/master/src/cron.c#L703

 case 'p':
 PermitAnyCrontab = 1;

Which in turn gets used https://github.com/cronie-crond/cronie/blob/40b7164227a17058afb4f3d837ebb3263943e2e6/src/database.c#L89

Makes cron less fussy about the crontab file's state (can be a non-regular file, can have a different owner, can have a mode that's not 400, can have a link count other than 1).

if (PermitAnyCrontab == 0)

While it's clearly present within cronie, such a feature is not present in Vixie Cron (https://github.com/svagner/vixie-cron)

edited 3 hours ago

answered 3 hours ago

steve

13.3k22251

Thanks. Can such a crontab file specified by -p be stored anywhere? Must it be user-specific crontab file, not system crontab file?
â€“Â Tim
3 hours ago

It can be a symlink to elsewhere. All it does is bypass a safeguards / checks really. Note it's crond itself, not crontab.
â€“Â steve
3 hours ago

Do you mean the file argument to -p must still be in either`/etc/cron.d/ or /varspool/cron/crontabs/, not anywhere in any filesystem?
â€“Â Tim
3 hours ago

add a commentÂ |Â

up vote
2
down vote

Good question. It doesn't appear to be documented within the man page. Looking at the source, we see -p sets PermitAnyCrontab, see https://github.com/cronie-crond/cronie/blob/master/src/cron.c#L703

 case 'p':
 PermitAnyCrontab = 1;

Which in turn gets used https://github.com/cronie-crond/cronie/blob/40b7164227a17058afb4f3d837ebb3263943e2e6/src/database.c#L89

Makes cron less fussy about the crontab file's state (can be a non-regular file, can have a different owner, can have a mode that's not 400, can have a link count other than 1).

if (PermitAnyCrontab == 0)

While it's clearly present within cronie, such a feature is not present in Vixie Cron (https://github.com/svagner/vixie-cron)

edited 3 hours ago

answered 3 hours ago

steve

13.3k22251

Good question. It doesn't appear to be documented within the man page. Looking at the source, we see -p sets PermitAnyCrontab, see https://github.com/cronie-crond/cronie/blob/master/src/cron.c#L703

 case 'p':
 PermitAnyCrontab = 1;

Which in turn gets used https://github.com/cronie-crond/cronie/blob/40b7164227a17058afb4f3d837ebb3263943e2e6/src/database.c#L89

Makes cron less fussy about the crontab file's state (can be a non-regular file, can have a different owner, can have a mode that's not 400, can have a link count other than 1).

if (PermitAnyCrontab == 0)

While it's clearly present within cronie, such a feature is not present in Vixie Cron (https://github.com/svagner/vixie-cron)

edited 3 hours ago

answered 3 hours ago

steve

13.3k22251

edited 3 hours ago

answered 3 hours ago

steve

13.3k22251

answered 3 hours ago

steve

13.3k22251

answered 3 hours ago

steve

13.3k22251

Thanks. Can such a crontab file specified by -p be stored anywhere? Must it be user-specific crontab file, not system crontab file?
â€“Â Tim
3 hours ago

It can be a symlink to elsewhere. All it does is bypass a safeguards / checks really. Note it's crond itself, not crontab.
â€“Â steve
3 hours ago

Do you mean the file argument to -p must still be in either`/etc/cron.d/ or /varspool/cron/crontabs/, not anywhere in any filesystem?
â€“Â Tim
3 hours ago

add a commentÂ |Â

Thanks. Can such a crontab file specified by -p be stored anywhere? Must it be user-specific crontab file, not system crontab file?
â€“Â Tim
3 hours ago

It can be a symlink to elsewhere. All it does is bypass a safeguards / checks really. Note it's crond itself, not crontab.
â€“Â steve
3 hours ago

Do you mean the file argument to -p must still be in either`/etc/cron.d/ or /varspool/cron/crontabs/, not anywhere in any filesystem?
â€“Â Tim
3 hours ago

Thanks. Can such a crontab file specified by -p be stored anywhere? Must it be user-specific crontab file, not system crontab file?
â€“Â Tim
3 hours ago

It can be a symlink to elsewhere. All it does is bypass a safeguards / checks really. Note it's crond itself, not crontab.
â€“Â steve
3 hours ago

Do you mean the file argument to -p must still be in either`/etc/cron.d/ or /varspool/cron/crontabs/, not anywhere in any filesystem?
â€“Â Tim
3 hours ago

add a commentÂ |Â

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