sed: replace a block of text

Question

I have a bunch of files, starting with a block of code and I'm trying to replace with another. Replace: ``` <?php $r = session_start(); (more lines) ``` With: ``` <?php header("Location: index.php"); (more lines of code) ``` So im trying to match the block with `sed 's/<?php
$r = session_start();/<?php
header...` but it doesn't work. I would appreciate help in what is happening here and how to achieve this. I'm thinking in doing this with python instead. Thanks!

Accepted Answer

This might work for you (GNU sed):

```
sed -i '1i\
This is a\
new block of\
code
1,/$r = session_start();/d' file 
```

Or if you prefer to place the new code in a file:

```
sed -i '1r replacement_code_file
1,/$r = session_start();/d' file
```

All on one line:

```
sed -i -e '1r replacement_code_file' -e '1,/$r = session_start();/d' file
```

sed: replace a block of text

Solution

Problem