The reason it does not work on directories is because a very vital part of a directory entry is the first two bytes which is the inode number of an entry.
The first two entries of a directory are named . and ..
So, if either inode numbers are different csum and/or cksum will report generally report different values.
read: octalDump -decimalCharacter /some/directory
This will output two lines for each entry in the directory /some/directory
The first line: first number is the inode number; second line (ignore first two values (are inode number in character notation) - remaining bytes are the file/directory name) Example:
Hope this helps/explains WHY cksum/csum does not work on directories.
hello all.
I'm not asking about the algorithm - or how it goes about computing the checksum - I'm asking how it views/looks at the files it does the cksum on.
For instance:
Say you had a directory named "dir_A"
And within this directory you had some files.
So:
dir_A
- file1
-... (5 Replies)
Hi there,
I have a query about cksum. I'm running a script on the Unix box and in a script the cksum result differs from when I run it manually. As far as I can see the file is not being changed, is there any other times that the cksum would be different. (4 Replies)
Hi,
I have a working script, well it works on my machine but when I try it on others the cksum section does not work properly (I know the scripting is not of a high quality but I'm just trying to get it working)
Heres the script:
#!/bin/sh
case $# in
0) echo "usage: enshar filename... (7 Replies)
hi,
I am trying to use the cksum feature in unix. when i make a call to it i get returned something along the lines of:
4603435 14 file3
how do i get the first part of this response only; i.e:
4603435
I'm trying to use at a way without the use of sed and creating temp... (4 Replies)
Hi,
On what factors does the cksum depend.
If i build 2 machines exactly the same, then can i get the checksum of 2 compiled files same.
Thanks (3 Replies)
Hi all,
So I have a binary file and I need to generate an expected EEPROM checksum for it. Ideally, I would like to input the file (with the path) and output a computed checksum. Ive been using (cksum file1) with no avail and I was just curious as to whether there is such thing as EEPROM cksum,... (1 Reply)
I did this:
ls -lrRt | grep ^* | cksum *
but it is showing cksum of sub-directories.
Thanks You
Please use code tags when posting data and code samples, thank you. (3 Replies)
Hi,
I am getting read error when i run cksum </dir> but this command runs successfully for the files and in different server it runs for both files and directories. I am using in both the servers solaris 10 with patch 148888-03. Please suggest...
# cksum ravi(directory)
3454912345 0... (3 Replies)
Discussion started by: Navkreddy
3 Replies
LEARN ABOUT OSX
tc-csum
Checksum action in tc(8) Linux Checksum action in tc(8)NAME
csum - checksum update action
SYNOPSIS
tc ... action csum UPDATE
UPDATE := TARGET [ UPDATE ]
TARGET := { ip4h | icmp | igmp | tcp | udp | udplite | sctp | SWEETS }
SWEETS := { and | or | + }
DESCRIPTION
The csum action triggers checksum recalculation of specified packet headers. It is commonly used to fix incorrect checksums after the pedit
action has modified the packet content.
OPTIONS
TARGET Specify which headers to update: IPv4 header (ip4h), ICMP header (icmp), IGMP header (igmp), TCP header (tcp), UDP header (udp),
UDPLite header (udplite) or SCTP header (sctp).
SWEETS These are merely syntactic sugar and ignored internally.
EXAMPLES
The following performs stateless NAT for incoming packets from 192.0.2.100 to new destination 198.51.100.1. Assuming these are UDP packets,
both IP and UDP checksums have to be recalculated:
# tc qdisc add dev eth0 ingress handle ffff:
# tc filter add dev eth0 prio 1 protocol ip parent ffff:
u32 match ip src 192.0.2.100/32 flowid :1
action pedit munge ip dst set 198.51.100.1 pipe
csum ip and udp
SEE ALSO tc(8), tc-pedit(8)iproute2 11 Jan 2015 Checksum action in tc(8)