sed

sed is a stream editor command using for parsing and transforming text. -i This option tells sed to edit files in place. It means the

Format:

s/pattern/replacement/flags

• s: Stands for substitution
• /: Delimiters that separate the pattern and the replacement.

Example, convert (foo.html) to (foo.html):

sed -i 's/\.html"/\.html"/g'

• \.html": The pattern to search for. Here:
  • \.: matches a literal dot .
  • md": matches the string
• \.html": The replacement string
• g: The global flag. It tells sed to replace all occurrences of the pattern in each line, not just for the first one.

Example, convert (foo.html#topic) to (foo.html#topic):

sed -i 's/\.html\(#*\)/\.html\1/g' ${file%.*}.html

• s/: Start the substitution command
• \.html\(#*\)/: The search pattern. \. matches a literal dot, md matches the string "md", and \(#*\) captures zero or more # characters
• .html\1/: The replacement pattern. .html is the replacement string, and \1 refers to the captured group of # characters.