I find a very common task that I need to do is find a string in a file and replace it with another string. Or better, find all instances of a given string and replace them with a new string. I figure others will need to do this as well. This is also an interesting example of how Mac OS X is not “the same” as Linux. The sed command can be used to quickly perform a find and replace inside of a file. The following example will use the -i option to do so in-place, defining no extensions to -i using the double quotes (“”), then using the /s…