[macos] In-place edits with sed on OS X

I'd like edit a file with sed on OS X. I'm using the following command:

sed 's/oldword/newword/' file.txt

The output is sent to the terminal. file.txt is not modified. The changes are saved to file2.txt with this command:

sed 's/oldword/newword/' file1.txt > file2.txt

However I don't want another file. I just want to edit file1.txt. How can I do this?

I've tried the -i flag. This results in the following error:

sed: 1: "file1.txt": invalid command code f

sed -i -- "s/https/http/g" file.txt

You can use:

sed -i -e 's/<string-to-find>/<string-to-replace>/' <your-file-path>

Example:

sed -i -e 's/Hello/Bye/' file.txt

This works flawless in Mac.

This creates backup files. E.g. sed -i -e 's/hello/hello world/' testfile for me, creates a backup file, testfile-e, in the same dir.

You can use -i'' (--in-place) for sed as already suggested. See: The -i in-place argument, however note that -i option is non-standard FreeBSD extensions and may not be available on other operating systems. Secondly sed is a Stream EDitor, not a file editor.

Alternative way is to use built-in substitution in Vim Ex mode, like:

$ ex +%s/foo/bar/g -scwq file.txt

and for multiple-files:

$ ex +'bufdo!%s/foo/bar/g' -scxa *.*

^{To edit all files recursively you can use **/*.* if shell supports that (enable by shopt -s globstar).}

Another way is to use gawk and its new "inplace" extension such as:

$ gawk -i inplace '{ gsub(/foo/, "bar") }; { print }' file1

I've similar problem with MacOS

sed -i '' 's/oldword/newword/' file1.txt

doesn't works, but

sed -i"any_symbol" 's/oldword/newword/' file1.txt

works well.

The -i flag probably doesn't work for you, because you followed an example for GNU sed while macOS uses BSD sed and they have a slightly different syntax.

All the other answers tell you how to correct the syntax to work with BSD sed. The alternative is to install GNU sed on your macOS with:

brew install gsed

and then use it instead of the sed version shipped with macOS (note the g prefix), e.g:

gsed -i 's/oldword/newword/' file1.txt

If you want GNU sed commands to be always portable to your macOS, you could prepend "gnubin" directory to your path, by adding something like this to your .bashrc/.zshrc file (run brew info gsed to see what exactly you need to do):

export PATH="/usr/local/opt/gnu-sed/libexec/gnubin:$PATH"

and from then on the GNU sed becomes your default sed and you can simply run:

sed -i 's/oldword/newword/' file1.txt