You may reading link below :
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- CentOS/RHEL Use yum Command To Downgrade Upgrade or Rollback Updates
- use inotify-tools on centos
- awk useful commands examples
To create checksum folder with 3 files
$ mkdir checksum
$ echo "huuphan.com" > file_md5
$ echo "Phan Van Huu" > file2_md5
$ echo "huupv" > file3_md5
$ ls -ll
total 12
-rw-r--r-- 1 huupv huupv 13 Jul 13 09:04 file2_md5
-rw-r--r-- 1 huupv huupv 6 Jul 13 09:04 file3_md5
-rw-r--r-- 1 huupv huupv 12 Jul 13 09:03 file_md5
To generate MD5 Checksum on a single file
$ md5sum file_md5
01ff693ecd0492aca683eed0dcd2bb44 file_md5
To generate MD5 Checksum on multiple files
$ md5sum file2_md5 file3_md5To generate MD5 Checksum and ouptut to file
de241737f915f7f10245f8362cfe7cf9 file2_md5
01380acd4b4e611399ee7087bf78642b file3_md5
$ md5sum file2_md5 file3_md5 > md5check.txt
$ cat md5check.txt
de241737f915f7f10245f8362cfe7cf9 file2_md5
01380acd4b4e611399ee7087bf78642b file3_md5
To compare MD5 Checkum output file to current file in directory
$ md5sum -c md5check.txt
file2_md5: OK
file3_md5: OK
if you modify file, then md5sum checksum faild.
$ echo "if you modify file then, md5sum faild" >> file2_md5you run command md5sum again after modify file
$ md5sum -c md5check.txt
file2_md5: FAILED
file3_md5: OK
md5sum: WARNING: 1 computed checksum did NOT match
$ md5sum file2_md5 file3_md5 > md5check.txt
Thanks for reading Generate and Verify Files with MD5 Checksum in Linux My blog Effortless Zimbra Mail Management: Unleashing the Power of Linux Commands, How-To, and Bash Scripts I hope this is useful.