On an Intel PIII 800 under linux with gcc and no optimization, I get the following:
Running the program with the hard-coded character searching and printing 100000 times (this is 100000 distinct calls to these functions), I get an average of 0.038 seconds per run. Using the constant character, I get an average of 0.039 seconds per run. So hard coding is more efficient.
You can also use the pre-processor to achieve some level of generality without sacrificing performance. Instead of defining a constant, just do:
Hi all
My question is related to following sample code which tries to change consant value by pointers.(I know it is wrong practice but i am surprised by mis-behaviour)
The code:
#include <stdio.h>
int main()
{
const int x = 10;
int *y;
const int * const z = &x;
y = (int *)&x;... (2 Replies)
is it possible to use eval to create constants in perl? i cannot seem to get anything to work, and my searches are turning up little to nothing. an example of what i am trying to do is this:
2 arrays:
array 1: 'FOOD','NUMBER','OS'
array 2: 'pizza','two','unix'
loop through the arrays and... (5 Replies)
currently it has the following:
bdumpN=`ll /home/apps/oracle/admin/DBprod/bdump/DBprod_j* | grep "$Cdate" | wc -l`
If I pass the DBname, I would not have to hardcode it in the script...
I can capture the database name by adding the following:
DBname=$1
The problem is, I have been unable... (2 Replies)
Hi
Can any one help me out ?
I am trying to send an autogenerated mail with an attachment to bulk of users using 'MAILX' and 'UNENCODE' . I have used it as follows
X " ( cat /sastemp/body.txt; uuencode Test.xls.gz Test.xls.gz ) | mailx -s 'Testing' ' abcd@yahoo.com , efgh@gmail.com ' "
... (9 Replies)
Hello there,
I'd like to define a variable b equal to 0.5/a where a=0.001, so I wrote something like that:
a=0.001;
let 'b=0.5/$a';
but it doesn't work... maybe because the variable a has a real value???
Any help will be appreciated!!!:D (1 Reply)
Hello,
I'm trying to write a method which will return the extension of a file given the file's name, e.g. test.txt should return txt. I'm using C so am limited to char pointers and arrays. Here is the code as I have it:
char* getext(char *file)
{
char *extension;
int i, j;... (5 Replies)
Compiling xpp (The X Printing Panel) on SL6 (RHEL6 essentially):
xpp.cxx: In constructor ‘printFiles::printFiles(int, char**, int&)’:
xpp.cxx:200: error: invalid conversion from ‘const char*’ to ‘char*’
The same error with all c++ constructors - gcc 4.4.4.
If anyone can throw any light on... (8 Replies)
Hi,
I would like to read content from a https site.
I have decided to use LWP module in perl. but it throwed 401 Authorization required error.
i dont want to hard code the password in my perl code. Is there any way to achieve the authentication without hardcoding the password.
Thanks,... (1 Reply)
Discussion started by: pandeesh
1 Replies
LEARN ABOUT LINUX
openssl_ia32cap
OPENSSL_ia32cap(3SSL) OpenSSL OPENSSL_ia32cap(3SSL)NAME
OPENSSL_ia32cap - finding the IA-32 processor capabilities
SYNOPSIS
unsigned long *OPENSSL_ia32cap_loc(void);
#define OPENSSL_ia32cap (*(OPENSSL_ia32cap_loc()))
DESCRIPTION
Value returned by OPENSSL_ia32cap_loc() is address of a variable containing IA-32 processor capabilities bit vector as it appears in EDX
register after executing CPUID instruction with EAX=1 input value (see Intel Application Note #241618). Naturally it's meaningful on
IA-32[E] platforms only. The variable is normally set up automatically upon toolkit initialization, but can be manipulated afterwards to
modify crypto library behaviour. For the moment of this writing six bits are significant, namely:
1. bit #28 denoting Hyperthreading, which is used to distiguish
cores with shared cache; 2. bit #26 denoting SSE2 support; 3. bit #25 denoting SSE support; 4. bit #23 denoting MMX support; 5. bit #20,
reserved by Intel, is used to choose between RC4 code
pathes; 6. bit #4 denoting presence of Time-Stamp Counter.
For example, clearing bit #26 at run-time disables high-performance SSE2 code present in the crypto library. You might have to do this if
target OpenSSL application is executed on SSE2 capable CPU, but under control of OS which does not support SSE2 extentions. Even though you
can manipulate the value programmatically, you most likely will find it more appropriate to set up an environment variable with the same
name prior starting target application, e.g. on Intel P4 processor 'env OPENSSL_ia32cap=0x12900010 apps/openssl', to achieve same effect
without modifying the application source code. Alternatively you can reconfigure the toolkit with no-sse2 option and recompile.
1.0.0e 2007-04-01 OPENSSL_ia32cap(3SSL)