How can I add a string to the beginning of each file in a folder in bash?

Question

I want to be able to prepend a string to the beginning of each text file in a folder. How can I do this using bash on Linux?

Answer 1

You can do this as well:

for f in *; do
  cat <(echo "someline") $f > tempfile
  mv tempfile $f
done

It's not much different from the 1st post but does show how to treat the output of the 'echo' statement as a file without having to create a temporay file to store the value.

Answer 2

A one-liner: rename '' string_ *

Answer 3

This is the easiest I have worked out.

sed -i '1s/^/Text to add then new file\n/' /file/to/change

Answer 4

And you can do this using sed in 1 single command as well

for f in *; do
  sed -i.bak '1i\
  foo-bar
  ' ${f}
done

Answer 5

Here is an example :

for f in *; 
do
    mv "$f" "whatever_$f"
done

Answer 6

This should do the trick.

FOLDER='path/to/your/folder'
TEXT='Text to prepend'
cd $FOLDER
for i in `ls -1 $FOLDER`; do
     CONTENTS=`cat $i`
     echo $TEXT > $i  # use echo -n if you want the append to be on the same line
     echo $CONTENTS >> $i
done

I wouldn't recommending doing this if your files are very big though.