How to copy and add prefix to file names in one step?

Question

I want to copy and rename multiple c source files in a directory.

I can copy like this:

$ cp *.c $OTHERDIR

But I want to give a prefix to all the file names:

file.c --> old#file.c

How can I do this in 1 step?

Solution 1

a for loop:

for f in *.c; do cp -- "$f" "$OTHERDIR/old#$f"; done

I often add the -v option to cp to allow me to watch the progress.

Solution 2

You can use shell globbing:

for f in *.c; do cp -- "$f" "$OTHERDIR/old#$f"; done

The for variable in GLOB format will expand the glob to all matching files/directories (excluding hidden-ones) and iterate over them, saving each in turn as $variable (in the example above, $f). So, the command I show will iterate over all non-hidden files, copying them and adding the prefix.

Solution 3

Here is a one-liner using xargs, tr and globbing. Might have some value.

echo *.c | tr ' ' '\n' | xargs -n1 -I{} cp "{}" "PREFIX{}"

This returns all files matching *.c as a space-separated string. Next, tr turns the extra spaces into newlines (N.B. did not test file names with spaces**). Then, xargs gets populated with each file name, and runs cp with the appropriate name and prefix.

*.c can be modified for other, useful globs. Other prefixes in the xargs and cp part can be used as well.

**for those with spaces in their filenames:

(requires find that supports -print0) Similar to above, we can use find to output a null-seperated list of files, and tweak xargs with a flag to separate on null

find . -name '*.c' -print0 | xargs -0 -n1 -I{} cp "{}" "PREFIX{}"

Comments

[don_crissti]

Don't loop over find's output. Don't use grep to exclude file names when find alone can do it.

[don_crissti]

Same here, don't loop over find's output

[Scott - Слава Україні]

And, if you had tested this with filenames containing spaces, you would have seen it fail.

[TonyH]

Thanks for call-out. I knew it probably failed but thought I had already procrastinated through enough of my workday with the first pass. 😀

[alexandernst]

If I do for f in /foo/bar/*.c, $f will contain the entire path, instead only the name of the file. How can I obtain only the name of the file?

[terdon]

@alexandernst either cd /foo/bar/; for f in *c, or use for f in /foo/bar/*.c; do name=${f##*/} ... or name=$(basename "$f").