A, md5sum: md5 checksum value calculation files and
Syntax
md5sum [option] ... [file] ...
Description
print or check MD5 (128-bit) checksum. FILE or FILE is not
-, read standard input.
-b, - binary
read in binary mode
-c, -check
read from the file and MD5 sum check
--tag create a BSD-style checksum
-t, - text
read in text mode (default)
Note: There is no option between binary and text mode difference
on the GNU system.
The following four options only when verifying checksums helpful:
- quiet
do for each successfully verified file print "OK"
- status
nothing output, status code shows success
- strictly
for improperly formatted checksum lines, exit non-zero value
-w, -warn
warning improperly formatted checksum lines
--help display this help and exit
- version
output version information and exit
Common examples:
Md5sum command to verify whether a file is changed
Second, the growth tailf- follow the log file
Syntax
tailf [OPTION] file
Description
tailf will print the last 10 lines of the file, and then wait for the
file growth. It is similar to tail -f, but not access the file
when it is not growing. Such side effects do not update
access time of the file, the file system refresh periodi not happen?
When no log activity occurs, it appears as cally.
tailf log files on the laptop monitor is very useful when
recording very few, and the user wishes rotating hard disk
in order to save battery life.
Mandatory parameters of long options are mandatory parameters short options
too.
-n, - lines = N, -N
outputs the last N rows, rather than the last 10 rows.
-V, - version
output version information and exit.
-h, - help
display this help and exit
Example:
