A couple of readers, upon reading this article to calculate yesterday’s date in a shell script, have requested for a similar script that can be used to calculate tomorrow’s date.

There are times when you will need to calculate yesterday’s date in a UNIX shell script to run some date sensitive cron jobs. There are currently no standard command line tools in UNIX to perform such date arithmetic.

Many coders do not think that creating temporary files in a secure way is important, especially in shell scripts. It’s just a temporary file, they might say. But a simple symbolic link exploit could make the whole system unusable.

When the disk partition is filling up quickly, it’s quite an hassle for the system administrator to find out the location of the files taking up the most space.