If you need to reduce the size of a file, then you would need to create a compressed version of it which is where zip compression comes into play. The file format with the extension .zip was created by Phil Katz in 1989 and was originally supported by only PKZIP utility. Today there are many software utilities available and most computer operating systems come with inbuilt ZIP support. One of the most important features of the file format is that it allows you to save on data storage space. By compressing files in this manner you can save up to 80% of the space originally occupied. It also saves on the time spent in sending an email with a zip attachment due to smaller file sizes. If you are sending across data which is classified then it is possible to encrypt files using different utilities that will protect your data. With so many different services available it is not a wonder that someone would want to learn to compress a file or more specifically zip it.
On a Mac
First and foremost create a folder of all the files that you want to compress. Name this folder as you would like. Now control-click the folder and choose the option create archive. Alternatively you can opt to click on the file, go to the Action menu and then choose the option to create archive from there. Once you have performed this task, it will create a compressed file with the extension .zip.
First collect all the files that you want to include in the compressed file in a folder. Name it properly. Now right click on the folder and select the send to option. This option will lead to a list of more options. Here select the option for compressed (zipped) folder. As soon as you click this option, you will see a dialog box that will keep you informed about how much progress has been made on the compression of the files. Once the folder has been compressed, you can easily attach it to your email with the extension .zip and send it. The process on Windows 7 is no different.
All you need to do is enter the command zip filename inputfile1 inputfile2 at the Unix prompt, wherein filename is the name that you want the file to take, and inputfile1 and inputfile2 are the names of the files you want to include in the compressed file you are creating. If you want to create a zip archive with all the contents of a directory, then you can use the code, zip -r filename directory where directory is the name of the directory you want to include in the archive. You can use programs like WinZip to decode the same.
There are utilities available that will prompt you to insert a removable disk in case the disk that you were creating the .zip file on runs out of space. This is known as disk spanning and does not affect the process in any manner. Extracting zip files is as easy as creating them and most utilities come with a self-extracting archive that allows you access to the files easily.