GNU basename in PL/SQL
In the process of scripting a database migration, I was in need of something akin to the GNU basename utility that I know and love on Linux. basename is most famous for taking a full file path string and stripping away the leading path component, returning just the name of the file. This can be emulated in PL/SQL with calls to SUBSTR and INSTR, like this:
substr(dirname,instr(dirname,'/',-1)+1)
(Thanks to Ian Cary, who shared this logic on oracle-l)
As you can see, this simply finds the last occurence of /, which is our directory separator on *nix and Solaris operating systems. On Windows, it would be \. It then returns a substring beginning one character after that last separator until the end of the string. Voila, a basic basename routine!
Upon reading the basename man page again, I found that basename also takes an optional parameter, a suffix string. If this suffix string is provided, basename will also truncate that string from the end. For example:
