10-18-2006
Problem with parsing a large file
Hi All,
Following is the sample file
Quote:
91,1
91,2
91,4
91,3
81,2
81,3
81,1
and following is the op desired
that is the last entry of each unique first field is required.
My solution is as follows
Quote:
cut -d "," -f1 rcont | sort -u > 1
$cat 1
81
91
$for var in `cat 1`
> do
> grep $var rcont | tail -1
> done
81,1
91,3
However the original file has around a million entries and around a 100,000 uniques first fields, so this soln. will take damn long time to execute.
Is there a better and faster way of doing it
Regards,
Gaurav
10 More Discussions You Might Find Interesting
1. UNIX for Advanced & Expert Users
Hello Everyone,
I can't transfer a large file (~15GB TAR Archive) from one linux machine to another via FTP.
I have tried the following:
1) Normal FTP the whole 15GB. This stops when it gets to about 2GB and doesn't go any further.
2) Split the 15GB file into 500MB pieces using the... (1 Reply)
Discussion started by: VVV
1 Replies
2. Shell Programming and Scripting
Hi Friends,
Getting an error while processing a very large file using an sqlloader........
The file is larger than 2 GB. Now need to change the compiler to 64-bit so that the file can be processed.
Is there any command for the same.
Thanks in advance. (1 Reply)
Discussion started by: Rohini Vijay
1 Replies
3. UNIX for Dummies Questions & Answers
Hi Friends,
I'mfacing a problem while doing ftp of a large file.The control session is getting closed after sometime.But data session transfers the file successfully even when the control seeion is lost.I need to make the control session available as long as data session is active.
How can i... (1 Reply)
Discussion started by: rprajendran
1 Replies
4. Shell Programming and Scripting
I need to parse a large log say 300-400 mb
The commands like awk and cat etc are taking time.
Please help how to process.
I need to process the log for certain values of current date.
But I am unbale to do so. (17 Replies)
Discussion started by: asth
17 Replies
5. UNIX for Advanced & Expert Users
We are experiencing a problem on a lengthy data transfer by FTP through a firewall. Since there are two ports in use on a ftp transfer (data and control), one sits idle while the other's transfering data. The idle port (control) will get timed out and the data transfer won't know that it's... (3 Replies)
Discussion started by: rprajendran
3 Replies
6. Shell Programming and Scripting
Dear Freind
in the file attached how parse the data to be like a normal table
:D (3 Replies)
Discussion started by: saifsafaa
3 Replies
7. UNIX for Dummies Questions & Answers
Hi folks,
I have a big problem.... and need help from your experience/knowledge.
I previously install and use FREEBSD 7.0 release on my storage/backup
file server, for some reason, I can not transfer any files that is bigger
than 1GB. If I transfer it to Freebsd file server, the system... (2 Replies)
Discussion started by: bsdme2
2 Replies
8. UNIX for Dummies Questions & Answers
I have a large file, around 570 gb that I want to copy to tape. However, my tape drive will load only up to 500 gb. I don't have enough space on disk to compress it before copying to tape. Can I compress and tar to tape in one command without writing a compressed disk file?
Any suggestions... (8 Replies)
Discussion started by: iancrozier
8 Replies
9. UNIX for Advanced & Expert Users
Hi ,
I want to transfer one file having 6GB(after compression) which is in .cpk format from one server to other server.
I tried scp command as well as FTP and also split the file then transfer the files thru scp command. At last i am facing the data lost and connection lost issue.
Generally it... (2 Replies)
Discussion started by: Sumit sarangi
2 Replies
10. Shell Programming and Scripting
I have a 1.2G file that contains no newline characters. This is essentially a log file with each entry being exactly 78bits long. The basic format is /DATE/USER/MISC/. The single uniform thing about the file is that that the 8 character is always ":"
I worked with smaller files of the same... (8 Replies)
Discussion started by: os2mac
8 Replies
LEARN ABOUT CENTOS
tpm_quote_tools
TPM QUOTE
TOOLS(8) TPM QUOTE TOOLS(8)
NAME
TPM Quote Tools
PROGRAMS
tpm_mkuuid, tpm_mkaik, tpm_loadkey, tpm_unloadkey, tpm_getpcrhash, tpm_updatepcrhash, tpm_getquote, tpm_verifyquote
DESCRIPTION
TPM Quote Tools is a collection of programs that provide support for TPM based attestation using the TPM quote operation.
A TPM contains a set of Platform Configuration Registers (PCRs). In a well configured machine, some of these registers are set to known
values during the boot up process or at other times. For example, a PCR might contain the hash of a boot loader in memory before it is
run.
The TPM quote operation is used to authoritatively verify the contents of a TPM's Platform Configuration Registers (PCRs). During provi-
sioning, a composite hash of a selected set of PCRs is computed. The TPM quote operation produces a composite hash that can be compared
with the one computed while provisioning.
To use the TPM quote operation, keys must be generated. During provisioning, an Attestation Identity Key (AIK) is generated for each TPM,
and the public part of the key is made available to entities that validate quotes.
The TPM quote operation returns signed data and a signature. The data that is signed contains the PCRs selected for the operation, the
composite hash for the selected PCRs, and a nonce provided as input, and used to prevent replay attacks. At provisioning time, the data
that is signed is stored, not just the composite hash. The signature is discarded.
An entity that wishes to evaluate a machine generates a nonce, and sends it along with the set of PCR used to generate the composite PCR
hash at provisioning time. For this use of the TPM quote operation, the signed data is ignored, and the signature returned is used to val-
idate the state of the TPM's PCRs. Given the signature, the evaluating entity replaces the nonce in the signed data generated at provi-
sioning time, and checks to see if the signature is valid for the data. If so, this check ensures the selected PCRs contain values that
match the ones measured during provisioning.
A typical scenario for an enterprise using these tools follows. The tools expect AIKs to be referenced via one enterprise-wide Universally
Unique Identifier (UUID). The program tpm_mkuuid creates one.
For each machine being checked, an AIK is created using tpm_mkaik. The key blob produced is bound to the UUID on its machine using
tpm_loadkey. The public key associated with the AIK is sent to the entities that verify quotes. Finally, the expected PCR composite hash
is obtained using tpm_getpcrhash. When the expected PCR values change, a new hash can be generated with tpm_updatepcrhash.
The program to obtain a quote, and thus measure the current state of the PCRs is tpm_getquote. The program that verifies the quote
describes the same PCR composite hash as was measured initially is tpm_verifyquote.
SEE ALSO
tpm_mkuuid(8), tpm_mkaik(8), tpm_loadkey(8), tpm_unloadkey(8), tpm_getpcrhash(8), tpm_updatepcrhash(8), tpm_getquote(8), tpm_verifyquote(8)
Oct 2010 TPM QUOTE TOOLS(8)