# 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`.