Linux

I looked all over trying to find an easy way to convert a date to a UNIX timestamp in a shell or perl script. I was disappointed that I didn't find anything that was easy, sure and didn't require extra software. Most of my UNIX scripts have to operate on Mac OS X so I don't concern myself too much about portability and generally try to use what's already available on the system.

The easiest way I found to convert a date string to a UNIX timestamp is with PHP's strtotime function. Fortunately, PHP is included on Mac OS X machine at no extra charge! This one-liner handles the need pretty well.



The constants: STDIN, STDOUT, and STDERR are predefined to make life easy!

For more info, check out: "Using PHP from the command line."

After making some path changes this blog here, I needed to update some of the URLs in previous entries (mainly image URLs). I thought it was going to be tough but it turns out there's an easy way to do it with a SQL one-liner.



I love simple solutions!

My conversion from cvs to svn caused a bunch of files to end up with svn:keywords set for Author, Date, Revision, and Id. I recursively deleted the svn:keywords property from all the files with the following command. This could work with other svn property commands as well.

I ran in to an issue the other day where I needed to perform some regular expression matching on a file and then edit the file's contents. Not a big problem really, I do it all the time, but this case was different as the file involved was encoded in UTF-16.

I see more and more Unicode files these days and at first I was worried by what I might have to do to manipulate this particular file. A little bit of research led me to something that made life super easy!

The UNIX command (available on Mac OS X and Debian boxes) 'iconv' does the work for me. 'iconv' can convert to any character set encoding available on your particular system. For my purposes, I just converted my UTF-16 file into a MacRoman file. Next, I manipulated to my heart's content, then I re-converted to UTF-16. It was easy as pie. I also used the command to convert a whole bunch of UTF-16 files to UTF-8, it was no problem. Here's the actual command in action:

Use the awk 'NF' (number of fields) built-in variable as an easy way to get the last field of a multi-word output. Here is an example using Mac OS X's hdiutil command to get just the calculated checksum of a disk image.