Add "use strict" everywhere

1-line.sh

find -name '*.js'|grep -v '^./node_modules'|while read f;do if (head -n3 "$f"|grep -Fv 'use strict'>/dev/null);then echo "$f";sed -i -e '1i "use strict"\n' "$f";fi;done

alias.sh

alias rigid="find -name '*.js'|grep -v '^./node_modules'|while read f;do if (head -n3 \"\$f\"|grep -Fv 'use strict'>/dev/null);then echo \"\$f\";sed -i -e '1i \"use strict\";\\n' \"\$f\";fi;done"

commented.sh

find -name '*.js'                                              `# Find all .js files in current directory, recursively` | \
grep -v '^./node_modules'                                      `# Exclude node_modules folder, you may want to add additional folders here` | \
while read f; do
  if (head -n3 "$f" | grep -Fv 'use strict' > /dev/null); then `# Check first three lines, thought about shebang`
    echo "$f"
    sed -i '1i "use strict"\n' "$f"                            `# Prepend "use strict", that may break your executable scripts`
  fi
done

warning-bsd.md

BSD (including Mac OS X) version of sed is not GNU's one, including a subtle difference with in-place remplacements.

On BSD systems, you HAVE TO replace occurrence of sed -i -e with sed -i '' -e to make it work.

I needed to check a huge codebase for use strict; at the top of every file and I was dreading it. I thought to myself "Surely nobody has expended the energy to solve this problem already."

Then I got here.

You are my hero. Seriously just saved me at least an hour or more trying to get something working together. So thank you.

For future wanderers, though, I did need to modify this slightly for use on a Mac.

1. brew install gnu-sed - Seriously, just do it. Makes life so, so much easier.
2. The find -name '*.js' command does not work on a Mac out of the box. You must specify a path as the first argument or the Mac chokes on it. I solved this problem like so:
   • find . -name '*.js'
3. Additionally, I had to reverse the last grep command to work on the Mac. Instead of inverting with the -v flag (which wasn't exiting with an error) I flipped it.
4. Finally, I replaced sed with gsed since I installed the gnu-sed package from brew.

The final command that worked for me (whitespace added for clarity) is as follows:

find . -name '*.js' |
grep -v '^./node_modules' |
while read f;do
  if (head -n3 "$f" | grep -F 'use strict'>/dev/null); then
    echo "[ OK ] $f"
  else
    echo "[FAIL] $f DOES NOT HAVE 'USE STRICT'!!!"
    gsed -i -e "1i \'use strict';\n" "$f";
  fi;
done

@rex, you are my hero :) Your final command has server me quite a bit.

Set it to use -n8, for our use case. (Comments come before use strict, though I guess it makes sense to see 'use strict' as the first line) Worked perfectly!