Here’s how to make a backup copy of a file:
$ cp MyLongFileName MyLongFileName.bak
Here’s a quicker way of achieving the same thing:
$ cp MyLongFileName{,.bak}
How it works
The shell expands the comma-separated list within the braces, appending each value in turn to the file name. The first character within the braces is a comma, so the first comma-separated string is null; the second is .bak. That means that the second command above expands to be exactly the same as the first.
Want to make a copy of all *.conf files in a directory?
$ for a in *.conf;do cp $a{,.bak};done
What’s your favourite Linux tip?
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