I am begining to learn bourne shell and as a practice I have written a script which when given the purchase price and percentage of discount calculates the savings.
I somehow cannot figure out why my script fails to do arthimatic calculation on real numbers.
Could anyone look at the script... (5 Replies)
Discussion started by: Tirmazi
5 Replies
3. Post Here to Contact Site Administrators and Moderators
page
unix com/answers-frequently-asked-questions/13785-yesterdays-date-date-arithmetic.html
Date Arithmetic with the Shell
has link of
www samag com/documents/s=8284/sam0307b/0307b.htm
which is no longer.
Is this the correct place to post this?:confused:
and I got message... (1 Reply)
Hello everybody,
I decided to take a Unix Introduction class and have never had experience with programming. Everything was fine until recently when the Prof. started shell scripting and he wants us to make a small script to add unlimited numbers from arguments and from standard input.
I... (1 Reply)
Hello everybody,
I decided to take a Unix Introduction class and have never had experience with programming. Everything was fine until recently when the Prof. started shell scripting and he wants us to make a small script to add unlimited numbers from arguments and from standard input.
I... (8 Replies)
I need help on arithmetic
root@server # hour=`date | awk {'print $4'} | cut -d: -f 1`; echo $hour
04
Now I subtract this result by 1 or 01 I get "3" as the answer. I need "03" as the answer, ie last two significant numbers should be there.
root@server # hour=`date | awk {'print $4'} | cut... (3 Replies)
Hi,
I need a help with arithmetic calculations in my script. I have two variables: a=17; b=1712
I want to perform ($a/$b)*100 with two decimals in the result.
I tried with following:
res=$((100*a/b))
res=`echo "scale=2; $a / $b" | bc`
But I am not getting the decimal values.... (4 Replies)
I am trying to perform arithmetric, for example, to increment the value of variable $a (say 3) by 0.05 but when I tried the following expression
let a=a+0.05
or a=$((a+0.05))
both returned
3.0499999999999998
I want to keep 2 decimal places so it returns 3.05 instead. (6 Replies)
i am having a varialbe a , which is input to my file
i want to multiply this input with value .43, and assign it to variable b.
i tried it as below:
#!/bin/sh
a=$1
b=`expr $1\*0.43`
echo b=$b
error : expr: non-integer argument
Please tell me , how to do this.
Thanks (10 Replies)
Hello,
I am having a problem when i execute following script on RHEL 6.4. Same script works fine on another machine where I have same version of RHEL and KSH.
Below is the rpm and RHEL version.
ossvm12(0)> rpm -qa | grep ksh
ksh-20100621-19.el6.x86_64
ossvm12(0)> cat... (7 Replies)
Discussion started by: Adithya Gokhale
7 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)