Sed substitution middle of string

Question

Trying to write a one liner to change my wallpaper through a config file. Tried adapting from: Replace regex capture group content using sed but I can't seem to get it right.

My config file contains the following string:

output * bg ~/pictures/wallpapers/old-wallpaper.jpg fill

I want to change the path in this string to something else.

This one makes most sense to me but doesn't capture correctly:

sed "/output \* bg /s|.* fill|~/path/to/foobar.jpg fill|" sed_file
output * bg ~/pictures/wallpapers/old-wallpaper.jpg fill

This one looks completely wrong but seems to get the job done. Although I think it replaces anything that starts with output.

sed "/output \* bg/s| .* fill| \* bg ~\/path\/to/foobar.jpg fill|" sed_file
output * bg ~/path/to/foobar.jpg fill

I would take a look at: awk '/^output/{ $4="foo" } { print }' file — Cyrus, Dec 30 '21 at 23:54
cool! that's a lot easier to do.. settled for awk '/^output \* bg/{ $4="foo" } { print }' — mork, Dec 31 '21 at 00:02
What's actually showing the image as wallpaper? It could probably be made to read a list of files... — Kusalananda, Dec 31 '21 at 11:25

score 1 · Accepted Answer · answered Dec 31 '21 at 00:12

1

With GNU sed. I assume your path contains no spaces or pipes. I switched from s/// to s|||.

sed -E 's|^(output \* bg) [^ ]+ |\1 foo |' file

Output:

output * bg foo fill

-E: use extended regular expressions

answered Dec 31 '21 at 00:12

Cyrus

1 Answers1