Index: head/sbin/md5/md5.1 =================================================================== --- head/sbin/md5/md5.1 +++ head/sbin/md5/md5.1 @@ -1,5 +1,5 @@ .\" $FreeBSD$ -.Dd June 15, 2020 +.Dd June 19, 2020 .Dt MD5 1 .Os .Sh NAME @@ -95,6 +95,48 @@ and 2 if at least one file does not have the same hash as the .Fl c option. +.Sh EXAMPLES +Calculate the MD5 checksum of the string +.Dq Hello . +.Bd -literal -offset indent +$ md5 -s Hello +MD5 ("Hello") = 8b1a9953c4611296a827abf8c47804d7 +.Ed +.Pp +Same as above, but note the absence of the newline character in the input +string: +.Bd -literal -offset indent +$ echo -n Hello | md5 +8b1a9953c4611296a827abf8c47804d7 +.Ed +.Pp +Calculate the checksum of multiple files reversing the output: +.Bd -literal -offset indent +$ md5 -r /boot/loader.conf /etc/rc.conf +ada5f60f23af88ff95b8091d6d67bef6 /boot/loader.conf +d80bf36c332dc0fdc479366ec3fa44cd /etc/rc.conf +.Ed +.Pp +Write the digest for +.Pa /boot/loader.conf +in a file named +.Pa digest . +Then calculate the checksum again and validate it against the checksum string +extracted from the +.Pa digest +file: +.Bd -literal -offset indent +$ md5 /boot/loader.conf > digest && md5 -c $(cut -f2 -d= digest) /boot/loader.conf +MD5 (/boot/loader.conf) = ada5f60f23af88ff95b8091d6d67bef6 +.Ed +.Pp +Same as above but comparing the digest against an invalid string +.Pq Dq randomstring , +which results in a failure. +.Bd -literal -offset indent +$ md5 -c randomstring /boot/loader.conf +MD5 (/boot/loader.conf) = ada5f60f23af88ff95b8091d6d67bef6 [ Failed ] +.Ed .Sh SEE ALSO .Xr cksum 1 , .Xr md5 3 ,