automatically append executable line to script files

Question

My hosting company requires me to put #!/usr/local/bin/ruby at the top of every RB file. Is there an easy way to use sed recursively or something that can go through and append this to the top of every rb file?

Answer 1

awk

$ awk 'NR==1{$0="#!/usr/local/bin/ruby\n"$0 }1' file > temp; mv temp file;

sed

sed -i.bak '1 i #!/usr/local/bin/ruby' file

to do it recursively, you can use find

find /path -type f -iname "*.rb" | while read -r FILE
do
    sed -i.bak '1 i #!/usr/local/bin/ruby' $FILE 
    # awk 'NR==1{$0="#!/usr/local/bin/ruby\n"$0 }1' >temp ; mv temp $FILe
done