How do I change extension of multiple files recursively from the command line?

A portable way (which will work on any POSIX compliant system):

find /the/path -depth -name "*.abc" -exec sh -c 'mv "$1" "${1%.abc}.edefg"' _ {} \;

In bash4, you can use globstar to get recursive globs (**):

shopt -s globstar
for file in /the/path/**/*.abc; do
  mv "$file" "${file%.abc}.edefg"
done

The (perl) rename command in Ubuntu can rename files using perl regular expression syntax, which you can combine with globstar or find:

# Using globstar
shopt -s globstar
files=(/the/path/**/*.abc)  

# Best to process the files in chunks to avoid exceeding the maximum argument 
# length. 100 at a time is probably good enough. 
# See http://mywiki.wooledge.org/BashFAQ/095
for ((i = 0; i < ${#files[@]}; i += 100)); do
  rename 's/\.abc$/.edefg/' "${files[@]:i:100}"
done

# Using find:
find /the/path -depth -name "*.abc" -exec rename 's/\.abc$/.edefg/' {} +

Also see http://mywiki.wooledge.org/BashFAQ/030


This will do the required task if all the files are in the same folder

rename 's/.abc$/.edefg/' *.abc

To rename the files recursively use this:

find /path/to/root/folder -type f -name '*.abc' -print0 | xargs -0 rename 's/.abc$/.edefg/'

One problem with recursive renames is that whatever method you use to locate the files, it passes the whole path to rename, not just the file name. That makes it hard to do complex renames in nested folders.

I use find's -execdir action to solve this problem. If you use -execdir instead of -exec, the specified command is run from the subdirectory containing the matched file. So, instead of passing the whole path to rename, it only passes ./filename. That makes it much easier to write the regex.

find /the/path -type f \
               -name '*.abc' \
               -execdir rename 's/\.\/(.+)\.abc$/version1_$1.abc/' '{}' \;

In detail:

  • -type f means only look for files, not directories
  • -name '*.abc' means only match filenames that end in .abc
  • '{}' is the placeholder that marks the place where -execdir will insert the found path. The single-quotes are required, to allow it to handle file names with spaces and shell characters.
  • The backslashes after -type and -name are the bash line-continuation character. I use them to make this example more readable, but they are not needed if you put your command all on one line.
  • However, the backslash at the end of the -execdir line is required. It is there to escape the semicolon, which terminates the command run by -execdir. Fun!

Explanation of the regex:

  • s/ start of the regex
  • \.\/ match the leading ./ that -execdir passes in. Use \ to escape the . and / metacharacters (note: this part vary depending on your version of find. See comment from user @apollo)
  • (.+) match the filename. The parentheses capture the match for later use
  • \.abc escape the dot, match the abc
  • $ anchor the match at the end of the string

  • / marks the end of the "match" part of the regex, and the start of the "replace" part

  • version1_ add this text to every file name

  • $1 references the existing filename, because we captured it with parentheses. If you use multiple sets of parentheses in the "match" part, you can refer to them here using $2, $3, etc.
  • .abc the new file name will end in .abc. No need to escape the dot metacharacter here in the "replace" section
  • / end of the regex

Before

tree --charset=ascii

|-- a_file.abc
|-- Another.abc
|-- Not_this.def
`-- dir1
    `-- nested_file.abc

After

tree --charset=ascii

|-- version1_a_file.abc
|-- version1_Another.abc
|-- Not_this.def
`-- dir1
    `-- version1_nested_file.abc

Hint: rename's -n option is useful. It does a dry run and shows you what names it will change, but does not make any changes.


Another portable way:

find /the/path -depth -type f -name "*.abc" -exec sh -c 'mv -- "$1" "$(dirname "$1")/$(basename "$1" .abc).edefg"' _ '{}' \;

# Rename all *.txt to *.text
for f in *.txt; do 
mv -- "$f" "${f%.txt}.text"
done

Also see the entry on why you shouldn't parse ls.

Edit: if you have to use basename your syntax would be:

for f in *.txt; do
mv -- "$f" "$(basename "$f" .txt).text"
done

https://unix.stackexchange.com/questions/19654/changing-extension-to-multiple-files