Splitting a large file into individual smaller ones and joining the target files into a new file equal to the original one is easy in the same operating system, but if you need to split a file in Windows and join them back in Linux or perform the inverse operation, you may be wondering whether or not the destination file is as same as the original one.
Suppose that you want to upload an encrypted backup file which is larger than 2GB from your Windows based computer to a Linux based server( for example, a virtual private server or a dedicated server ), but your upload bandwidth is very poor, your should split the file into smaller, more transferable ones before you upload them.
The Linux OSes( CentOS, Ubuntu, RedHat, etc. ) have a command called “split” which allows users to perform the split action with ease, but the Windows OSes do not have such a command. Fortunately, FFSJ( the author’s homepage, direct download link( portable version ), review ) is a small piece of program which can be used to split and merge files in a breeze, you can use it to split your files in one of two ways: split into n equal-size parts or split after ever n Bytes/KBs/MBs/GBs, if the input file is 8A4FFC53d01.flv, it will be splitted into the following files: 8A4FFC53d01.flv.001, 8A4FFC53d01.flv.002, 8A4FFC53d01.flv.003, 8A4FFC53d01.flv.004, 8A4FFC53d01.flv.005, etc.
After you have split the gigantic file into small pieces, you can upload them to the server with FileZilla or other FTP client applications, now it’s time to combine them to a gigantic one, login the server with putty, navigate to the directory of the files uploaded just now, type in the following command to perform the merging operation:
Alternatively, the command below does the same thing:
Once the process is completed, you can verify the integrity of your file by comparing the MD5 checksum between the file on your hard drive and one on the server, just type in the command below to let Linux compute the MD5 checksum of the file “output.flv”:
A new line will appears in the screen which shows you the result:
Finally, you can copy the MD5 checksum of the file on the server to the clipboard by highlighting the string in putty with mouse, and press the “Ctrl + V” shortcut key combination or click on the “paste” button to paste the string from clipboard into the editbox in the FCV window, FCV will compare the two strings automatically, a tick icon will be displayed if they are same, a cross icon will be displayed if they do not match.