问题
I am trying to rename using "mv", because "rename" command doesn't work in my Mac terminal.
I have a bunch of files named
DTM001_ACGGT-TTAGGC.fq
DTM156_GGTTG-ACAGTG.fq
...etc
I wish to rename them to
DTM001.fq
DTM156.fq
I suppose the easier way is to remove the last 13 characters before the file extension?
I tried these links:
- mac os x terminal batch rename
- Rename file by removing last n characters
- Removing last n characters from Unix Filename before the extension
but none have worked for me, perhaps because I do not fully understand how to manipulate the answers for my specific case or some answers use "rename" command which I cannot access.
回答1:
The macOS Terminal is simply an interface to an interactive program called a shell. The default shell's name is bash.
What you are looking for is known as a shell script, or a bash script, to rename files.
The questions you referenced have the answer. To reiterate:
cd directory_with_the_files
for file in *.fq; do
mv -vn "${file}" "${file%_*}.fq"
done
You can type this all in at the command line, or place it into a file and execute it with:
bash file_containing_the_commands
This will go through all .fq files in the current directory, renaming them to what you want. The -v option to mv simply means to print the rename as it happens (useful to know that it's doing something), and the -n flag means don't accidentally overwrite any files (in case you type something in wrong or come across duplicate numbers).
All the magic is happening in the ${file%_*}.fq, which says
"remove everything after the first _ and add the .fq back". This is known as a "shell parameter expansion," which you can read more about in the Bash Reference Manual. It's somewhat obtusely worded, but here is the relevant bit to this particular use case:
${parameter%word}
The word is expanded to produce a pattern just as in filename expansion. If the pattern matches a trailing portion of the expanded value of parameter, then the result of the expansion is the value of parameter with the shortest matching pattern (the '%' case) deleted.
回答2:
The simplest way is to use rename - see instructions at the end for installation on a Mac.
So, in answer to your question, you can see what would happen if you replace (the command is actually s for "substitute") everything from the first underscore to the end of the filename with .fq:
rename --dry-run 's/_.*/.fq/' *fq
'DTM001_ACGGT-TTAGGC.fq' would be renamed to 'DTM001.fq'
'DTM156_GGTTG-ACAGTG.fq' would be renamed to 'DTM156.fq'
If that looks good, remove the --dry-run and run it again for real.
You can use rename on your Mac, if you install it. By default, Apple doesn't ship a package manager with macOS. So, many folk use homebrew from the homebrew website.
If you have that, you can simply install rename with:
brew install rename
Then, you'll have a package manager and you can benefit for all sorts of lovely software including new, up-to-date versions of all the out-of-date, ancient versions of your favourite tools that Apple ships:
- PHP
- Perl
- ImageMagick
- GNU sed
- GNU awk
- GNU find
- GNU Parallel
- zeromq
- htop
- socat
- sox
- ffmpeg
- youtube-dl
- zenity
- redis
- feh
- mosquitto
- doxygen
- pandoc etc.
来源：https://stackoverflow.com/questions/50547881/how-can-i-remove-the-last-n-characters-of-filenames-in-a-certain-directory-in-m