how does one use DD to recombine files from using pipe to split files originally?

nerdful1 · 03-27-2006, 07:07 PM

I have read awesomemachine post and tutorial on using DD. Then there was an argument about recombining files using cat. Awesome said not to use cat, other poster said cat worked fine for him. I want to learn DD properly to recombine my split files using dd.
I used dd and piped to split to .gz files. Now I want to put them back together again.

pixellany · 03-27-2006, 10:19 PM

dd does not combine or split files---apparently you used dd to generate a stream which you then split. (And then compressed?)
"cat" is used to merge files---why did someone say not to use it?

you can also append to a file using redirection, e.g.:
"cat file2 >> file1" appends the contents of file2 onto file1

nerdful1 · 03-27-2006, 11:12 PM

awesomemachine said not to use cat. Although I would use cat if it was the only way, now that I am using dd why not use dd to reverse the process? I'm sure cat would work, but I find myself sent on tangents in LINUX.

pixellany · 03-28-2006, 07:46 AM

Quote:

Originally Posted by nerdful1

awesomemachine said not to use cat. Although I would use cat if it was the only way, now that I am using dd why not use dd to reverse the process? I'm sure cat would work, but I find myself sent on tangents in LINUX.

I asked WHY he said "don't use cat"...

dd is not what split your files--it does not do that!!!! --- dd is a low-level read-write utility.
In general, you would not use a variant of the same command to "reverse the process". (There are exceptions)

I know 2 methods: cat and >> (append) You could also try a Google search using "combine files in Linux"---or some such...