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

I'd use the mmv command from the package of the same name:

mmv ';*.abc' '#1#2.edefg'

The ; matches zero or more */ and corresponds to #1 in the replacement. The * corresponds to #2. The non-recursive version would be

mmv '*.abc' '#1.edefg'

This is what I did and worked pretty just the way I wanted. I used the mv command. I had multiple .3gp files and I wanted to rename them all to .mp4

Here's a short oneliner for it:

for i in *.3gp; do mv -- "$i" "ren-$i.mp4"; done

Which simply scans through the current directory, picks up all .3gp files, then renames (using the mv) into ren-name_of_file.mp4

I found an easy way to achieve this. To change extensions of many files from jpg to pdf, use:

for file in /path/to; do mv $file $(basename -s jpg $file)pdf ; done

Rename files and directories with find -execdir | rename

If you are going to rename both files and directories not simply with a suffix, then this is a good pattern:

PATH="$(echo "$PATH" | sed -E 's/(^|:)[^\/][^:]*//g')" \
  find . -depth -execdir rename 's/findme/replaceme/' '{}' \;

The awesome -execdir option does a cd into the directory before executing the rename command, unlike -exec.

-depth ensure that the renaming happens first on children, and then on parents, to prevent potential problems with missing parent directories.

-execdir is required because rename does not play well with non-basename input paths, e.g. the following fails:

rename 's/findme/replaceme/g' acc/acc

The PATH hacking is required because -execdir has one very annoying drawback: find is extremely opinionated and refuses to do anything with -execdir if you have any relative paths in your PATH environment variable, e.g. ./node_modules/.bin, failing with:

find: The relative path ‘./node_modules/.bin’ is included in the PATH environment variable, which is insecure in combination with the -execdir action of find. Please remove that entry from $PATH

See also: Why using the '-execdir' action is insecure for directory which is in the PATH?

-execdir is a GNU find extension to POSIX. rename is Perl based and comes from the rename package. Tested in Ubuntu 18.10.

Rename lookahead workaround

If your input paths don't come from find, or if you've had enough of the relative path annoyance, we can use some Perl lookahead to safely rename directories as in:

git ls-files | sort -r | xargs rename 's/findme(?!.*\/)\/?$/replaceme/g' '{}'

I haven't found a convenient analogue for -execdir with xargs: https://superuser.com/questions/893890/xargs-change-working-directory-to-file-path-before-executing/915686

The sort -r is required to ensure that files come after their respective directories, since longer paths come after shorter ones with the same prefix.