使用Bash按变量值替换PHP文件内容的问题排查

Let's break down why your current command isn't working and walk through the correct solutions step by step:

What's Wrong With the Original Command? #

Your command wraps the sed script in single quotes, which tells the shell to treat everything inside as a literal string. That means $testPattern and $test never get expanded to their actual values—sed is literally trying to match the string "$testPattern" instead of your /* TEST */ marker. On top of that, the * and / in your marker are special characters in sed's regular expressions, so even if the variables did expand, sed would misinterpret them as regex syntax instead of literal text.

Solution 1: Use GNU Sed's Literal Matching (Simplest) #

If you're using GNU sed (standard on most Linux systems), you can use \Q and \E to wrap your pattern. This tells sed to treat everything between them as a literal string, so you don't need to escape special characters like * or /.

First, confirm your variables are defined correctly (no syntax issues here):

test="defined('_TEST') or die('Test test');"
testPattern="/* TEST */"

Then run this command to replace the markers in place:

find . -name "*.php" -exec sed -i -e "s/\Q$testPattern\E/$test/g" {} \;

How This Works: #

• Double quotes around the sed script let the shell expand $testPattern and $test to their actual values before passing them to sed.
• \Q turns on literal matching mode, \E turns it off—so sed will look for the exact string /* TEST */ instead of trying to parse it as a regex.

Solution 2: Manual Escaping (For BSD Sed, e.g., macOS) #

If you're using macOS's default BSD sed, it doesn't support the \Q/\E syntax. Instead, you need to escape the special characters in your pattern first:

1. Escape / and * in your test pattern to make them literal for sed:

escapedPattern=$(printf '%s' "$testPattern" | sed 's/[\/\*]/\\&/g')

This converts /* TEST */ to \/\* TEST \*\/, which sed will recognize as the exact string you want to match.

2. Run the find/sed command (note the empty string after -i—BSD sed requires this to skip creating backup files):

find . -name "*.php" -exec sed -i '' -e "s/$escapedPattern/$test/g" {} \;

Verify Before Modifying Files #

Before using -i to edit files in place, you can test the command by removing -i (and the empty string for BSD sed) to print the modified content to your terminal:

# GNU sed test
find . -name "*.php" -exec sed -e "s/\Q$testPattern\E/$test/g" {} \;

# BSD sed test
find . -name "*.php" -exec sed -e "s/$escapedPattern/$test/g" {} \;

This lets you confirm the replacement works correctly before making permanent changes to your PHP files.

内容的提问来源于stack exchange，提问作者Irina