I have a Bash script that copies the prior day's mail log file from
/var/log/maillog.1to another directory for archiving. The archive directory contains a subdirectory for each year's mail logs. Today is the first day of a new year, so I needed to create a 2017 directory. I could manually create the directory, but I thought I'd modify the Bash script that runs from Cron to check on whether the current year's directory exists and, if it doesn't create it, so, if I forget in future years to create a new year's directory the script will create it for me.
You can check if a directory exists with code similar to what is shown below:
if [ -d "$DIRECTORY" ]; then # Insert code to be executed fi
Or, to check if a directory doesn't exist and execute commands if it doesn't:
if [ ! -d "$DIRECTORY" ]; then # Insert code to be executed fi
Note: putting the $DIRECTORY variable in double quotes allows for cases where the directory name may contain a space. Though that won't be the case for my yearly subdirectories, it is something you can allow for by enclosing the variable name in double quotes.
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