[EnglishFrontPage] [TitleIndex] [WordIndex

How can I get a file's permissions (or other metadata) without parsing ls -l output?

There are several potential ways, most of which are system-specific. They also depend on precisely why you want the information; in most cases, there will be some other way to accomplish your real goal. You don't want to parse ls's output if there's any possible way to avoid doing so.

Many of the cases where you might ask about permissions -- such as I want to find any files with the setuid bit set -- can be handled with the find(1) command.

For some questions, such as I want to make sure this file has 0644 permissions, you don't actually need to check what the permissions are. You can just use chmod 0644 myfile and set them directly.

If you want to see whether you can read, write or execute a file, there are test -r, -x and -w.

If you want to see whether a file is zero bytes in size or not, you don't need to read the file's size into a variable. You can just use test -s instead.

If you want to copy the modification time from one file to another, you can use touch -r. The chown command on some GNU/Linux systems has a --reference option that works the same way, letting you copy the owner and group from one file to another.

If your needs aren't met by any of those, and you really feel you must extract the metadata from a file into a variable, then we can look at a few alternatives:


2012-07-01 04:05