Why percent signs (%) do not work in crontab?

I'm writing files out to a log ran by a bash script using cron. The call on cron looks like this:

*/25 * * * * bash script.sh > "/var/log/$(date +%Y-%m-%d_%H:%M).log"

But when I check the crontab it records as

*/25 * * * * bash script.sh > "/var/log/$(date +).log"

And it never writes the log file. Is there something I need to change to get cron to write the date?

edited Apr 25 '16 at 11:39

fedorqui

167k53341381

asked Apr 26 '13 at 14:04

Devin Dixon

3,7141656115

add a comment |

I'm writing files out to a log ran by a bash script using cron. The call on cron looks like this:

*/25 * * * * bash script.sh > "/var/log/$(date +%Y-%m-%d_%H:%M).log"

But when I check the crontab it records as

*/25 * * * * bash script.sh > "/var/log/$(date +).log"

And it never writes the log file. Is there something I need to change to get cron to write the date?

edited Apr 25 '16 at 11:39

fedorqui

167k53341381

asked Apr 26 '13 at 14:04

Devin Dixon

3,7141656115

add a comment |

I'm writing files out to a log ran by a bash script using cron. The call on cron looks like this:

*/25 * * * * bash script.sh > "/var/log/$(date +%Y-%m-%d_%H:%M).log"

But when I check the crontab it records as

*/25 * * * * bash script.sh > "/var/log/$(date +).log"

And it never writes the log file. Is there something I need to change to get cron to write the date?

edited Apr 25 '16 at 11:39

fedorqui

167k53341381

asked Apr 26 '13 at 14:04

Devin Dixon

3,7141656115

I'm writing files out to a log ran by a bash script using cron. The call on cron looks like this:

*/25 * * * * bash script.sh > "/var/log/$(date +%Y-%m-%d_%H:%M).log"

But when I check the crontab it records as

*/25 * * * * bash script.sh > "/var/log/$(date +).log"

And it never writes the log file. Is there something I need to change to get cron to write the date?

linux bash date cron crontab

edited Apr 25 '16 at 11:39

fedorqui

167k53341381

asked Apr 26 '13 at 14:04

Devin Dixon

3,7141656115

edited Apr 25 '16 at 11:39

fedorqui

167k53341381

asked Apr 26 '13 at 14:04

Devin Dixon

3,7141656115

edited Apr 25 '16 at 11:39

fedorqui

167k53341381

edited Apr 25 '16 at 11:39

fedorqui

167k53341381

edited Apr 25 '16 at 11:39

fedorqui

167k53341381

asked Apr 26 '13 at 14:04

Devin Dixon

3,7141656115

asked Apr 26 '13 at 14:04

Devin Dixon

3,7141656115

asked Apr 26 '13 at 14:04

Devin Dixon

3,7141656115

add a comment |

1 Answer
1

active

oldest

votes

It is a matter of escaping variables:

* * * * * /usr/bin/touch /tmp/$(date +%Y:%m).log

#                                      ^   ^

worked to me.

From man 5 crontab:

Percent-signs (%) in the command, unless escaped with backslash (), will be changed into newline characters, and all data after the first % will be sent to the command as standard input.

*/25 * * * * /bin/bash script.sh > "/var/log/$(date +%Y-%m-%d_%H:%M).log"

#                                                    ^    ^   ^   ^   ^

should work.

_{Note I used /bin/bash instead of just bash.}

edited Apr 25 '16 at 11:29

answered Apr 26 '13 at 14:21

fedorqui

167k53341381

add a comment |

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1 Answer
1

active

oldest

votes

1 Answer
1

active

oldest

votes

It is a matter of escaping variables:

* * * * * /usr/bin/touch /tmp/$(date +%Y:%m).log

#                                      ^   ^

worked to me.

From man 5 crontab:

Percent-signs (%) in the command, unless escaped with backslash (), will be changed into newline characters, and all data after the first % will be sent to the command as standard input.

*/25 * * * * /bin/bash script.sh > "/var/log/$(date +%Y-%m-%d_%H:%M).log"

#                                                    ^    ^   ^   ^   ^

should work.

_{Note I used /bin/bash instead of just bash.}

edited Apr 25 '16 at 11:29

answered Apr 26 '13 at 14:21

fedorqui

167k53341381

add a comment |

It is a matter of escaping variables:

* * * * * /usr/bin/touch /tmp/$(date +%Y:%m).log

#                                      ^   ^

worked to me.

From man 5 crontab:

Percent-signs (%) in the command, unless escaped with backslash (), will be changed into newline characters, and all data after the first % will be sent to the command as standard input.

*/25 * * * * /bin/bash script.sh > "/var/log/$(date +%Y-%m-%d_%H:%M).log"

#                                                    ^    ^   ^   ^   ^

should work.

_{Note I used /bin/bash instead of just bash.}

edited Apr 25 '16 at 11:29

answered Apr 26 '13 at 14:21

fedorqui

167k53341381

add a comment |

It is a matter of escaping variables:

* * * * * /usr/bin/touch /tmp/$(date +%Y:%m).log

#                                      ^   ^

worked to me.

From man 5 crontab:

Percent-signs (%) in the command, unless escaped with backslash (), will be changed into newline characters, and all data after the first % will be sent to the command as standard input.

*/25 * * * * /bin/bash script.sh > "/var/log/$(date +%Y-%m-%d_%H:%M).log"

#                                                    ^    ^   ^   ^   ^

should work.

_{Note I used /bin/bash instead of just bash.}

edited Apr 25 '16 at 11:29

answered Apr 26 '13 at 14:21

fedorqui

167k53341381

It is a matter of escaping variables:

* * * * * /usr/bin/touch /tmp/$(date +%Y:%m).log

#                                      ^   ^

worked to me.

From man 5 crontab:

Percent-signs (%) in the command, unless escaped with backslash (), will be changed into newline characters, and all data after the first % will be sent to the command as standard input.

*/25 * * * * /bin/bash script.sh > "/var/log/$(date +%Y-%m-%d_%H:%M).log"

#                                                    ^    ^   ^   ^   ^

should work.

_{Note I used /bin/bash instead of just bash.}

edited Apr 25 '16 at 11:29

answered Apr 26 '13 at 14:21

fedorqui

167k53341381

edited Apr 25 '16 at 11:29

answered Apr 26 '13 at 14:21

fedorqui

167k53341381

answered Apr 26 '13 at 14:21

fedorqui

167k53341381

answered Apr 26 '13 at 14:21

fedorqui

167k53341381

add a comment |

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