Question

I’m well aware of the source (aka .) utility, which will take the contents from a file and execute them within the current shell.

Now, I’m transforming some text into shell commands, and then running them, as follows:

$ ls | sed ... | sh

ls is just a random example, the original text can be anything. sed too, just an example for transforming text. The interesting bit is sh. I pipe whatever I got to sh and it runs it.

My problem is, that means starting a new sub shell. I’d rather have the commands run within my current shell. Like I would be able to do with source some-file, if I had the commands in a text file.

I don’t want to create a temp file because feels dirty.

Alternatively, I’d like to start my sub shell with the exact same characteristics as my current shell.

update

Ok, the solutions using backtick certainly work, but I often need to do this while I’m checking and changing the output, so I’d much prefer if there was a way to pipe the result into something in the end.

sad update

Ah, the /dev/stdin thing looked so pretty, but, in a more complex case, it didn’t work.

So, I have this:

find . -type f -iname '*.doc' | ack -v '\.doc$' | perl -pe 's/^((.*)\.doc)$/git mv -f $1 $2.doc/i' | source /dev/stdin

Which ensures all .doc files have their extension lowercased.

And which incidentally, can be handled with xargs, but that’s besides the point.

find . -type f -iname '*.doc' | ack -v '\.doc$' | perl -pe 's/^((.*)\.doc)$/$1 $2.doc/i' | xargs -L1 git mv

So, when I run the former, it’ll exit right away, nothing happens.

Answer 1

$ ls | sed ... | source /dev/stdin

UPDATE: This works in bash 4.0, as well as tcsh, and dash (if you change source to .). Apparently this was buggy in bash 3.2. From the bash 4.0 release notes:

Fixed a bug that caused `.’ to fail to read and execute commands from non-regular files such as devices or named pipes.