chmod

chown

See the output of cron by doing

sudo grep CRON /var/log/syslog

Count lines in files in current directory

find . -type f | xargs cat | wc -l 

MTA errors in cron can be solved by installing Postfix aptitude install postfix. Select the Local only configuration.

tail -f /var/mail/<your_username>. do

tail -f /var/mail/root

to look at cron errors sent to root's email

bash scripts start with #!/bin/sh. If you get errors, you may have leading BOM characters (ef bb bf) in your file. Check this by doing

head -n 1 myscript.sh | hexdump -C

2>&1 means send stderr to stdout.

redirects stdout to afile.txt.

echo test 1> afile.txt

To redirect stderr, you do

echo test 2> afile.txt