Unsure about the behaviour of my script when writing to log file

Question

I have a very simple ksh script and at certain points I want to write to a log file. I use the following commands in two places...

print "Directory listing 1:\n" > ${LogFile}
ll >> ${LogFile}

(Note: The second time this command is used print Directory listing 2)

My problem is, when I view the log file afterwards, only the second execution of these commands work! So there's no "Directory listing 1" and accompanying "ll" output.

I have tested and tested the script to ensure that there's nothing wrong my logic. I've added print test commands just before each so I know they get executed.

Is there something I've done wrong or I'm not realising?

Answer 1

Whenever you do a redirection with > (your first line), the ${LogFile} is truncated to 0 and then written. If I understand right, you do the above twice, the first stuff is overwritten by the second.

What you have to do is along the lines:

> ${LogFile}    # This just truncates if there was anything there, writes nothing
 ...
echo "First round" >> ${LogFile}
ls -l >> ${LogFile}
 ...
echo -e "\nSecond round" >> ${LogFile}
ls -l >> ${LogFile}
 ...