md5 - BSD md5 vs GNU md5sum输出格式？

任何人都知道为什么BSD md5程序会以这种格式产生哈希输出...

MD5 (checksum.md5) = 9eb7a54d24dbf6a2eb9f7ce7a1853cd0

...虽然GNU md5sum会产生更明智的格式？

9eb7a54d24dbf6a2eb9f7ce7a1853cd0 checksum.md5

据我所知，md5sum格式更容易解析并且更有意义。您如何用md5进行md5sum -check？ -p，-q，-r，-t，-x选项是什么意思？ man md5对这些选项什么也没说! :|

最佳答案

我想是历史原因。同时，-q禁止输出“MD5(...)=”，因此md5 -q checksum.md5给出

9eb7a54d24dbf6a2eb9f7ce7a1853cd0

This is implied if md5 is not given any arguments and it reads from stdin.Unfortunately md5sum in this case leaves "-" behind the checksum ("9eb7a54d24dbf6a2eb9f7ce7a1853cd0 -"),so if you're looking for some generic function to return the checksum, here is what might help:

checksum() {
        (md5sum <"$1"; test $? = 127 && md5 <"$1") | cut -d' ' -f1
}
checksum /etc/hosts

FreeBSD's man page says about the arguments

-p Echo stdin to stdout and append the checksum to stdout.

 -q      Quiet mode ‐ only the checksum is printed out.  Overrides the -r
         option.

 -r      Reverses the format of the output.  This helps with visual diffs.
         Does nothing when combined with the -ptx options.

 -t      Run a built‐in time trial.

 -x      Run a built‐in test script.

Checksum

md5 - BSD md5 vs GNU md5sum输出格式？