Okay i was able to get the checksum of the files of the directory and sub directories..how do I get the list with the checksum and the file permissions and dates in the same file...now this is driving me crazy...can anyone help me with this ? ls -ltraR + checksum to a file
Dear All
I have written a client server program for file transmission from one system to other using UDP.
Can i use the cksum number in the udp header to validate if the received packet is corrupted or not? If yes, how can i extract the header and validate it..
Also is there any way that... (3 Replies)
Hello friends,
I am looking for a script or method that can display all the dates between any 2 given dates.
Input:
Date 1
290109
Date 2
010209
Output:
300109
310109
Please help me. Thanks. :):confused: (2 Replies)
Hi, I am creating a ksh script to search for a string of text inside files within a directory tree. Some of these file are going to be read/execute only. I know to use chmod to change the permissions of the file, but I want to preserve the original permissions after writing to the file. How can I... (3 Replies)
Hi All,
I have spooled some data in a file (a.dat, b.dat etc..) and after that I want to get the size and checksum of spooled file (a.dat, b.dat etc..) in a log file(file_info.log).
By the way I dont want lost the previous output file info(Append data).
View of log file that I want to... (5 Replies)
Hello
I am communicating with two devices using my computer over UDP protocol. The application is running fine. When I monitored the UDP traffic using Wireshark software, I found that there were too many Checksum errors.
Please find attached the png file showing this error. I am about to... (0 Replies)
Hi All,
I am trying to print the dates that falls between 2 date variables into a file. Here is the example.
$BUS_DATE =20120616
$SUB_DATE=20120613
Output to file abc.txt should be : 20120613,20120614,120120615,20120616
Can you pls help me accomplish this in LINUX.
Thanks... (5 Replies)
hi all i want a script to FTP a file and should generate a quality checksum file
means when I FTP a file from one server to another server it should generate a QC file which should contain timestamp,no.of records in that file
Thanks in advance
saikumar (3 Replies)
I have one utility in VB which generates attached file(circle.14.mdn_range.properties_VB) & i have created other file(circle.14.mdn_range.properties_UTLFILE) having same contents with UTL_FILE(Oracle running on solaris). But checksum is different for both the files with same contents. Can you... (7 Replies)
Hi, We have an AIX server and have CURL 7.40 installed in it.
We are struggling to perform checksum on the file present on the remote server (AWS). We want to validate the checksum on the file pre and post download to make sure that there is no issue with the file.
We are writing a shell... (0 Replies)
Hi Folks,
I need a UNIX script which will copy files(Table wise) from source directory to destination directory (Under table directory) and also creates 2 additional files after getting copied to destination directory with extension .pdy and .ldy , . pdy file will be zero byte file should get... (4 Replies)
Discussion started by: Nicks1412
4 Replies
LEARN ABOUT OPENDARWIN
sum
CKSUM(1) BSD General Commands Manual CKSUM(1)NAME
cksum, sum -- display file checksums and block counts
SYNOPSIS
cksum [-o 1 | 2 | 3] [file ...]
sum [file ...]
DESCRIPTION
The cksum utility writes to the standard output three whitespace separated fields for each input file. These fields are a checksum CRC, the
total number of octets in the file and the file name. If no file name is specified, the standard input is used and no file name is written.
The sum utility is identical to the cksum utility, except that it defaults to using historic algorithm 1, as described below. It is provided
for compatibility only.
The options are as follows:
-o Use historic algorithms instead of the (superior) default one.
Algorithm 1 is the algorithm used by historic BSD systems as the sum(1) algorithm and by historic AT&T System V UNIX systems as the
sum(1) algorithm when using the -r option. This is a 16-bit checksum, with a right rotation before each addition; overflow is dis-
carded.
Algorithm 2 is the algorithm used by historic AT&T System V UNIX systems as the default sum(1) algorithm. This is a 32-bit checksum,
and is defined as follows:
s = sum of all bytes;
r = s % 2^16 + (s % 2^32) / 2^16;
cksum = (r % 2^16) + r / 2^16;
Algorithm 3 is what is commonly called the '32bit CRC' algorithm. This is a 32-bit checksum.
Both algorithm 1 and 2 write to the standard output the same fields as the default algorithm except that the size of the file in
bytes is replaced with the size of the file in blocks. For historic reasons, the block size is 1024 for algorithm 1 and 512 for
algorithm 2. Partial blocks are rounded up.
The default CRC used is based on the polynomial used for CRC error checking in the networking standard ISO/IEC 8802-3:1989. The CRC checksum
encoding is defined by the generating polynomial:
G(x) = x^32 + x^26 + x^23 + x^22 + x^16 + x^12 +
x^11 + x^10 + x^8 + x^7 + x^5 + x^4 + x^2 + x + 1
Mathematically, the CRC value corresponding to a given file is defined by the following procedure:
The n bits to be evaluated are considered to be the coefficients of a mod 2 polynomial M(x) of degree n-1. These n bits are the bits
from the file, with the most significant bit being the most significant bit of the first octet of the file and the last bit being the
least significant bit of the last octet, padded with zero bits (if necessary) to achieve an integral number of octets, followed by one
or more octets representing the length of the file as a binary value, least significant octet first. The smallest number of octets
capable of representing this integer are used.
M(x) is multiplied by x^32 (i.e., shifted left 32 bits) and divided by G(x) using mod 2 division, producing a remainder R(x) of degree
<= 31.
The coefficients of R(x) are considered to be a 32-bit sequence.
The bit sequence is complemented and the result is the CRC.
DIAGNOSTICS
The cksum and sum utilities exit 0 on success, and >0 if an error occurs.
SEE ALSO md5(1)
The default calculation is identical to that given in pseudo-code in the following ACM article.
Dilip V. Sarwate, "Computation of Cyclic Redundancy Checks Via Table Lookup", Communications of the ACM, August 1988.
STANDARDS
The cksum utility is expected to conform to IEEE Std 1003.2-1992 (``POSIX.2'').
HISTORY
The cksum utility appeared in 4.4BSD.
BSD April 28, 1995 BSD