Using sed to Edit a Specific Range in a Large File

In response to a request for editing a specific substring within a large file without affecting the whole file, the author suggests using the Unix sed command.

First, the author recommends consulting the manual page with man sed to understand the address syntax, especially the “line number” concept.

The relevant sed address format is BeginLineNumber,EndLineNumber{sed command} , which allows operations to be limited to a range of lines.

Applying this, the example command to replace “qunar” with “qunar.com” only in lines 1 through 100 of a large file is:

cat your_large_file | sed -e '1,100s#qunar#qunar.com#g' > your_large_file_after_edit

This demonstrates how to safely edit a specific region of a file using sed without resorting to risky regular‑expression replacements.