copying 1 file to many directories
 

The current directory contains:

• A file called "original.txt"
• Many directories called "source_001", "source_002", "source_003" ...

From the command line how do you copy "original.txt" to
"source_001"
and
"source_002"
and
"source_003" ...

The total number of these source directories is unknown, it changes every week.

Could it be done with links instead?

Those in the know understand what you mean by "links". Someone new to *nix, won't know that "links" implies the ln command. Use man ln for details of the command itself.

Here is a short description of "links". Every file system uses some variation of the following. A file exists as a series of bytes on the disk, often called an "extent". A structure called an "inode" keeps track of where the data lives on disk. A folder or directory is just another data file that happens to contain "filenames", some other details, and details about the data extent.

In most cases, there is a one-to-one relationship between what appears in the directory and the data file. Like an entry in a library card index, a "link" makes an entry in some directory for data that lives on the disk somewhere else just like one library book might have dozens of index cards. A given set of data might have a large number of these index-card-like duplicate entries. There is no reason for these links to have identical names, but you need to keep track of them.

A major advantage is that you have one copy of the data regardless of how many directories are used to name it and which users own those directories and link entries.

A major disadvantage of links is that you must remember to clean-up all of them when you delete the associated data file. (I vaguely remember that the fsck family of commands will notice and report and help deal with this issue. I welcome comments from someone who knows.)

One example of link use is the System-V style system initialization.
The system startup scripts get stored in /etc/init.d -- for example, apm, named, networking, samba, gdm, and so on. Then each of the runlevel folders holds a link, for example /etc/rc5.d/S15networking, that then points to the actual script.

One copy of the script content. Edit one -- edit them all. Link to that content each place that you want to use it.

~~~ 0;-Dan

Moved to Linux--Newbie