Add Replace Pattern Across Many Files In A Project as a Unix TIL

unix/replace-pattern-across-many-files-in-a-project.md

@@ -0,0 +1,28 @@
+# Replace Pattern Across Many Files In A Project
+
+Let's say I have a bunch of files in the `db/migrate` directory of my project
+that contain a line of text I'd like to update. I want to replace all
+occurrences of `t.bigint` with `t.integer`.
+
+First, I can get an idea of the scope of the change by listing out all the
+files and lines where this pattern exists using
+[`ripgrep`](https://github.com/BurntSushi/ripgrep).
+
+```bash
+$ rg 't.bigint' db/migrate
+```
+
+I can visually do a quick scan to make sure I'm not picking up results with my
+pattern that weren't intended.
+
+Then, I can include the `--files-with-matches` flag to limit the `ripgrep`
+output to just filenames. Those filenames can be piped to `sed` (via `xargs`)
+which will do the pattern replacement.
+
+```bash
+$ rg --files-with-matches 't.bigint' db/migrate | \
+  xargs sed -i '' 's/t.bigint/t.integer/g'
+```
+
+This does an in-place (`-i ''`) edit of the files substituting (`s///g`)
+globally the occurrences of `t.bigint` for `t.integer`.