#!/bin/bash # Add 'syntax="proto2";' to the beginning of all proto files under # PWD(recursively) if the proto file does not have it. for file in $(find . -name "*.proto"); do if grep -q 'syntax\s*=\s*"proto2";' $file; then echo "[already had] $file"; else sed -i '1s/^/syntax="proto2";\n/' $file echo "[replaced] $file" fi done