[SOLVED] Reformat headers in Markdown files with sed fails

Issue

I tried to reformat headers in a markdown file with sed but somehow that doesn't seem to work. Problem is that between the header # sign(s) and the header text needs to be one space, otherwise it is not correctly displayed.

So i tried to run several variations of sed commands to add this space after the # signs

sed -i "s/<expression>/\1 /g" test.md

<expression> being:

• ^\(\s*#+\)
• ^\(\[#\]+\)
• ^\(\[\#\]+\)

-i should replace this inside the file, but when i review the file with cat test.md, the space is still missing. I even added a backslash in front of the space in the substitute, but no luck.

The content of test.md is the following example data:

#Heading 1
Some text
- a list entry
- another one
##Heading 2
text
##Heading 3

The command should result in e.g. line 1 # Heading 1

What am i missing?

Solution

You need to escape the plus sign, e.g.:

^\(\s*#\+\)

Answered By - Michael Vehrs