[SOLVED] crontab -e command locks up terminal

newheart42108 · 04-11-2021, 02:57 PM

I am trying to make cron jobs work, and several sources online said to use the command crontab -e to view the cron table. However, when I try to do so, the terminal hangs up.

How do I a) prevent this from happening, and b) unlock the terminal when it does?

This is on a CentOS server.

frankbell · 04-11-2021, 08:08 PM

No clue as to what's happening/not happpening, but some troubleshooting questions come to mind:

When you enter the command, does an editor appear?

If you have not previously specified a crontab editor, are you asked to pick one?

Is there an error message, or does the terminal just freeze and become unresponsive?

Ser Olmy · 04-11-2021, 09:15 PM

A wild guess: Does pressing the keys "Esc", ":", "q" and finally Enter perhaps unlock the terminal?

newheart42108 · 04-11-2021, 11:04 PM

@frankbell - no, the cursor disappears in the Terminal window and the terminal is unresponsive.
@serOlmy - I don't have access to the server right now, but I will check your suggestion in the morning.

newheart42108 · 04-12-2021, 02:23 PM

I have removed all the user cron jobs and that has eliminated the cron -e problem. One of them obviously is seriously malformed.

I set up a minimal cron script

Code:

#!/usr/bin/php
<?php
date_default_timezone_set('America/Chicago');
echo "This is the output on " . date("M j, ") . 'at ' . date("G:i:s") .'<br>';
?>

This script displays the echo on screen as intended when I run it in a browser.

The cron job is

Code:

* * * * * /home/orgamya/public_html/develop/cronTest.php > /home/orgamya/public_html/develop/logs/testlog.log 2>%1

a look at tail /var/log/cron shows that the script has been called, but the output is not seen in testlog.log. crontest.php has permission 744 and testlog has permission 644.

What have I missed?

frankbell · 04-12-2021, 08:28 PM

Quote:

I have removed all the user cron jobs and that has eliminated the cron -e problem. One of them obviously is seriously malformed.

Nice catch!

Unfortunately, I don't know enough to answer your follow-up question.

evo2 · 04-12-2021, 08:46 PM

Hi,

Quote:

Originally Posted by newheart42108

The cron job is

Code:

* * * * * /home/orgamya/public_html/develop/cronTest.php > /home/orgamya/public_html/develop/logs/testlog.log 2>%1

a look at tail /var/log/cron shows that the script has been called, but the output is not seen in testlog.log. crontest.php has permission 744 and testlog has permission 644.

What have I missed?

Errors are probably ending up in a file called "%1". I think you want "2>&1" not "2>%1".

Also, if you just want to view the crontab use "crontab -l" instead of "crontab -e".

Evo2.

rnturn · 04-12-2021, 09:07 PM

Quote:

Originally Posted by newheart42108

I am trying to make cron jobs work, and several sources online said to use the command crontab -e to view the cron table. However, when I try to do so, the terminal hangs up.

I'm wondering if this isn't an environment setting problem.

Anyway... you can simply use "crontab -l" to view a cron table.

Another option: If "crontab -e" is acting, uh, "wonky", keep your crontab under $HOME (say, "my.crontab"), edit it there, and "submit" it using "crontab $HOME/my.crontab".

Just a thought...

newheart42108 · 04-12-2021, 09:24 PM

Thanks, @evo2. That at least got me error messages in my log file.

Cleaning up a couple more php errors got me nearly to what I wanted:

I was under the impression that adding the shebang in the php file would allow php to be processed. This is apparently not the case. Adding the /usr/bin/php in the cron command cleared that up.

Code:

/usr/bin/php /home/orgamya/public_html/develop/cronTest.php > /home/orgamya/public_html/develop/logs/testlog.php

There appears to be no time zone "America/Chicago" for US CST in php. I'll have to research what that should be.

The last issue is that I thought that cron logs automatically appended new lines to the log file defined. Is there a command I have to add to make that happen? I am seeing the new log line overwrite what's already in the file.

michaelk · 04-12-2021, 10:01 PM

Code:

#!/usr/bin/php
<?php
date_default_timezone_set('America/New_York');
echo "This is the output on ".date("M j, ").'at '.date("G:i:s")." EDT\n";
date_default_timezone_set('America/Chicago');
echo "This is the output on ".date("M j, ").'at '.date("G:i:s")." CDT\n";
date_default_timezone_set('America/Denver');
echo "This is the output on ".date("M j, ").'at '.date("G:i:s")." MDT\n";
date_default_timezone_set('America/Los_Angeles');
echo "This is the output on ".date("M j, ").'at '.date("G:i:s")." PDT";
?>
This is the output on Apr 12, at 22:45:14 EDT
This is the output on Apr 12, at 21:45:14 CDT
This is the output on Apr 12, at 20:45:14 MDT
This is the output on Apr 12, at 19:45:14 PDT

Using PHP 7.4.16 works for me. By the way, /usr/bin/php is the command line interpreter which is different then the apache php parser module used for php web pages. When using the shebang, if the php script is executable it should be executable from a cron script as long as the other permissions are set correctly. With redirection, using a single > overwrites the file, using >> appends.

newheart42108 · 04-12-2021, 10:13 PM

Thanks to all. I hope this helps someone down the road.

@michaelk I originally had 'America/Chicago' but was shown an error. I just inserted it again and all was well. Now that I am over the frustration of getting NOTHING, I will be able to make changes and examine the results.

Oh, and BTW, changing the > to >> before the output path solved the overwrite vs append issue