More than 10 years ago I created binary editor for Windows called xedit. I mentioned this tool already twice here. To find these posts put in search text box xedit and click on Search button. This tool does a lot of useful things with files and I still utilize it sometime. It is still available to download from http://xedit.smike.ru/. Xedit permits to split file to pieces and gather it back again. Now I want to present how to split and combine file in Linux. Let us split executable shred which overwrites a file to hide its contents, and optionally deletes it. Before to do this I copy shred utility to tmp directory:
Step 1. Splitting to pieces with sizes of 10 Kbyte and add numerical extension to each piece:
split -b 10K -d shred shred.part |
Step 2. Splitting result:
# ls -l shred* -rwxr-xr-x. 1 root root 52928 Jan 10 15:49 shred -rw-r–r–. 1 root root 10240 Jan 10 15:53 shred.part00 -rw-r–r–. 1 root root 10240 Jan 10 15:53 shred.part01 -rw-r–r–. 1 root root 10240 Jan 10 15:53 shred.part02 -rw-r–r–. 1 root root 10240 Jan 10 15:53 shred.part03 -rw-r–r–. 1 root root 10240 Jan 10 15:53 shred.part04 -rw-r–r–. 1 root root 1728 Jan 10 15:53 shred.part05 |
Step 3. Check that size of pieces is 10 Kbyte:
# echo $((10240/1024)) 10 |
Step 4. Join file from pieces. New name of combined file is shred1:
cat shred.part0[0-5]>shred1 |
Step 5. Compare files shred and shred1:
# md5sum shred 90a1bfcac01b3ef8b5ad4192c75bc5a6 shred # echo "90a1bfcac01b3ef8b5ad4192c75bc5a6 shred1" | md5sum -c shred1: OK |