Best way to iterate through a bunch of files and search/replace text?

Question

I'm having some trouble doing something that should be fairly simple. Here is how I imagine it would work:

find . -name *.txt -exec sed 's/oldtext/newtext/g' {} > tmp \\; mv tmp {} \;

Unfortunately I can't sed a file and dump to itself. But I can't figure out how to dump to a temp file and then immediately mv that file. I know \\; is wrong but I can't figure out how to run one command followed by the other.

Answer 1

See the -i option in man sed.

-i[SUFFIX], --in-place[=SUFFIX]

edit files in place (makes backup if extension supplied)

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Less useful but relatedly, you can also string multiple -execs together; they're executed left to right.

tmp=$(tempfile)
find . -name '*.txt' -exec sed 's/oldtext/newtext/g' '{}' > $tmp \; -exec mv $tmp '{}' \;

(Note the quoting of *.txt, {} and the escaping of ; to not have them interpreted by your shell.)