Question

I want to replace all pairs of square brackets in a file, e.g., [some text], with \macro{some text}, e.g.:

This is some [text].
This [line] has [some more] text.

This becomes:

This is some \macro{text}.
This \macro{line} has \macro{some more} text.

• The pairs only occur on individual lines, never across multiple lines.
• Sometimes there might be more than one pair on a single line, but they are never nested.
• If a bracket is found alone on a line, without a pair, then it should not be changed.

How can I replace these pairs of brackets with this code?

Answer 1

sed -e 's/\[\([^]]*\)\]/\\macro{\1}/g' file.txt

This looks for an opening bracket, any number of explicitly non-closing brackets, then a closing bracket. The group is captured by the parens and inserted into the replacement expression.