Linux patch file example

patchfile.sh

#!/bin/bash
mkdir modules
cat > modules/f1  << EOM
String 1
String for replace
EOM

cat > modules/f2 << EOM
String 1
String replaced
EOM

# diff -Naur f1 f2

# cat << EOF | patch -p0
# --- f1
# +++ f1
# @@ -1,2 +1,2 @@
#  String 1
# -String for replace
# +String replaced
# EOF

# diff -Naur modules/f1 modules/f2

cat << EOF | patch -p1
--- old/modules/f1
+++ new/modules/f1
@@ -1,2 +1,2 @@
 String 1
-String for replace
+String replaced
EOF