Unix Shell Loop through files and replace texts

问题:

I am fairly new to this stuff, and I need a shell file to loop through all ".xml" files in a folder, and do some text replacements. So far I have come up with this:

sed "s/old_text/new_text/g" testfile.xml -i

However, I want this to run on all xml files in the current folder, not just on "testfile.xml". Furthermore, how can I make a backup of the original file ?

Any input is more than welcomed! Thankls a lot!

回答1:

To run sed on all the xml files, just specify the wildcard

sed "s/old_text/new_text/g" *.xml -i

To create a backup, just specify the extension after -i:

sed "s/old_text/new_text/g" *.xml -i~

Note that's usually better to use XML aware tools to handle XML.

回答2:

For all .xml files that lie in the current directory:

sed -i.bak 's/old_text/new_text/g' *.xml

To recurse into subdirectories, combine with find:

find . -name '*.xml' -exec sed -i.bak 's/old_text/new_text/g' '{}' \;

The backup files will end in .xml.bak this way (the parameter to -i is appended to the original file name).

回答3:

a practical shell script, if you intend to sanitize a bunch of files with a number of measures – things that will get a little impractical on a single line...

# only take files form certain subfolders and certain extensions

# be careful to not tamper with .git or .svn folders 
# - thus excluding all hidden folders as an extra precaution
# - also tampering with node_modules is a bad idea

FILES=$(find . -type f -regextype posix-extended     \
    -regex "^\./(public|source)/.*\.(scss|js)$"         \
    -not -regex ".*\/(\.|node_modules).*")

for f in $FILES
do
echo "Processing $f file..."

# all files: prune trailing whitespace on each file.
sed -i 's/ *$//' $f

if [[ $f =~ \.js$ ]]; then
    echo "javascript file!"
    # DO stuff
fi

if [[ $f =~ \.scss$ ]]; then
    echo "scss file!"
    # \b whole word matching – stackoverflow.com/a/1032039/444255
    sed -i 's/\#000\b/black/g' $f
    sed -i 's/\#000000\b/black/g' $f
    sed -i 's/\#fff\b/white/g' $f
    sed -i 's/\#ffffff\b/white/g' $f
fi

done

caveat: with great power comes great responsibility, and mass-replacement means great power...