How to extract archive or change permissions when there are "read-only file system" errors?

Question

I am using Ubuntu 14.04 and having a problem changing the file permission of a .zip file. I can neither extract it nor change file permissions. When I extract it by command

unzip Ex_Files_JS_EssT_2011.zip

it shows me the following error:

checkdir error:  cannot create Ex_Files_JS_EssT_2011
read-only file system
unable to process Ex_Files_JS_EssT_2011

When I'm execute the command sudo chmod 777 Ex_Files_JS_EssT_2011.zip it gives me the following error:

chmod: changing permissions of ‘Ex_Files_JS_EssT_2011.zip’: Read-only file system

Solution

The file is on a read-only filesystem. This may be a disk that cannot be written to (such as most CDs). Or it may be on a disk that can be written to, mounted to allow reading only.

With more information about where the file is located, you might be able to remount the filesystem read-write. But if not, or if you don't want to bother with that (which you probably don't), there is a generic solution. Simply copy the archive to some location that you can write to. Then you can extract it.

You can do this in Nautilus (the graphical file browser). You can even extract the archive graphically, if you wish (either by double-clicking on its icon, or by right-clicking on its icon and clicking one of the Extract options).

Or if you want to use the command line, you can do:

cp Ex_Files_JS_EssT_2011.zip ~/Desktop
cd ~/Desktop
unzip Ex_Files_JS_EssT_2011.zip

That example copies it to your desktop and extracts it there. You might prefer to instead copy it to your home folder (which your desktop exists as a subfolder of), by replacing ~/Desktop with ~/, or perhaps to the global temporary folder /tmp by replacing ~/Desktop with that.