Can one of you point me towards a comprehensive print function tutorial in perl? I was under the impression that everything within quotes will get interpolated - but I am running into exceptions where it is not desirable to run some varaibles under quotes.
ordinal.pl
1 #!/usr/bin/perl
2 $idx = 1;
3 foreach $letter (a..z) {
4 print "Letter #",$idx++," is: $letter
";
5 #print "Letter # $idx++ is: $letter
[Code]...
I'm having a bit of an issue using overloaded operators in an already overloaded operator. In my following code, I have overloaded the && operator to compare two Course objects. The operator in turn goes to a function which calls other overloaded operators to compare private object variables of that object to compare them.
View 8 Replies View RelatedThis pretend to be a script for rename a lot of files automatically. So I put the list of files in an array named @lista. But, as you can see, at the end of the command I use a sed filter to print out a backslash for those files that have spaces in their names, so the path for those files could be rightly interpreted.
But there's no way I could print a backslash. It works well when I use the Perl's sed substitution s///, but I need every path in the array to be fixed.
I'd like to add that the bash command works perfectly well alone. I mean outside the Perl script.
This is de command line with the sed filter:
Code:
And this is what it brings:
Code:
Its my first post in here so please be patient I am trying to use regex in perl script to detect allowed words from the file and then print output to the screen.
As an example : I have text file with orders and returns :
Item2-SKU-2-11.08.2010-online
Item3-SKU-3-11.09.2010-return
Item4-SKU-4-11.09.2010-store
My question: is it possible to make sure that i am ony outputing to the screen orders based on few conditions like Item,order form e.g. online.And is it possible to have multiple matches (Item2 only diplay if ordered online etc)
Is there anyway in Linux that can achieve atomic increment/decrement for an integer variable without being interrupted? It means that the thread should not chance for other thread to run until theincrement/decrement is completed.
View 11 Replies View RelatedI have an big doubt in increment and decrement in c programmingi am trying to compile the below code in gcc
Code:
#include<stdio.h>
main()
[code]....
How do I get this loop to stop on each increment? This script does work but I would like it to stop at each increment, remember what the value of $n is, then continue until it gets to 7. I have worked so hard on this. My brain is hurting now.
[Code]...
I work in a simulations environment. I'm trying to write a bash script that will read fields from a .csv file into an array, the first field being an identifiyng number and the second field being a corresponding url. There are about 1600 of these number/url combinations in the .csv file that i'm reading from. Once that is done i want it to parse a text file and match the number, when it has a match i want it to enter the corresponding url into a particular line in the text file. The script I have written (with the help of the people on this forum a while back) does this well, but now I have a lot more data to parse. I think the script itself is explanatory enough to see what i'm doing. What i would like to do is cut it down to one while loop nested inside another loop so that I don't have 1600 or so elif statements. I can't figure out how to increment the output of the array. for instance, the first cycle would find the number that matches ${record1[2]} and input the url stored in ${record1[3]}. the next cycle would match ${record1[4]} and input the url in ${record1[5]}, and so on, does that make sense? The code is below and a sample .csv and text file are attached.
[Code]...
I'm having a bit of trouble getting the OR operator to work.This is the code that I have:
global.php:
Code:
$vars["admin link"] = "<a href='/path/to/admin.php'>Admin</a>";
$vars["admin ip"] = "xxx.xxx.xxx.xx1";
$vars["admin ip2"] = "xxx.xxx.xxx.xx2";
[Code]...
I have a binary value which I receive from a controller. Say this binary value is 42. Just plain hex 42. If you would look at that byte in a debugger you would see 42.Now this value hold 8 bits each indicating a high or a low output. So 0x42 = 01000010b. Which means bits 1 and 6 are '1'.When I would want to find out which bits are set and which are not in a language like C, I simply do:
Code:
mask = 0x80;
if (binval & mask) {...}
etc..
However I am programming in TCL, and I try to do:
Code:
set mask 0x80
if { [expr ($binval & $mask) > 0] } {...}
etc...
this fails. At the moment the expr is executed, $binval is evaluated and substituted so the expression I am evaluating is
Code:
set mask 0x80
if { [expr ('B' & '0x80') > 0] } {...}
etc...
Eventually I got it working by converting the $binval into a '0x42' string value, like this:
Code:
binary scan $binval c byte
set byte [format "0x%0x" $byte]
set mask 0x80
if { [expr ($byte & $mask) > 0] } {...}
etc...[
Then the expression yields what I want. But this seems so stupid and clumsy. Isn't there a better way where I can compare two binary values without conversions?
I have a simple program from book C++ cookbook, page 291, 8.3, Using Constructors and Destructors to manage resources (or RAII), but it can not get compiled in my g++
------------------------------------------------------------------------------------------------
// Example 8-3. Using constructors and destructors
#include <iostream>
#include <string>
using namespace std;
[code]....
I'm very new at Bash scripting and have a bone head issue that I'm trying (and failing) to resolve. I cannot get this one IF statement to work, it seems the comparison operator does not think the resulting number from the $b*$c+$b operation is an integer even though it is a number. Below is a small proof of concept script with the bit I'm having trouble with.
Code:
#! /bin/bash
a=800
b=700
c=.15
if [ "$a" -le "$(echo "($b*$c+$b)"|bc)" ]
[Code]...
Is there a way to achieve the following with the square bracket operator?I have a class:
Code: Select allclass A
{
public:
void SetValue(int index, Item* B);
private:
int m_iCount;
ItemCollection Item_Collection;
[code]....
The probelm is that I am not just blindly assigning whatever given on the right hand side to the returned value from operator [], I need to verify it's not NULL, and it is not already there in the Item_Collection, and I also need to increase the count.
I know it is wrong to use the "==" operator to compare the equality of two floating point numbers. Logically it would seem that if the "==" operator is not usable for floating point comparison, then the "<=" operator would also not be usable. Is this true? The lack of google search results on this topic made me think that it must be true. If that is true, then is it true that the only way to compare floats with <= or >= is with something like the code below? Code: bool smaller_than_or_equal(float a, float b) {
if ( fabs(a-b) < EPSILON){return true;}
else if (a < b) {return true;}
else {return false;}
} I think this is a general question, but if specifics are necessary, I am using the C++ language to code at the moment.
I am trying to learn C++.I implemented a simple archive program, and I am in a situation in which the user is prompted by a menu to make a choice.So I have some cout instruction to illustrate the possible choices and then
int choice;
cin>>choice;
and everything works fine.I introduced this code in a "while" loop that checks wether the choice made by the user is valid or not:
bool check=true;
int choice;
while(check)
{
cin>>choice;
if(the choice is valid) {...;check=false}
else cout<<"please make an other choice"
}
What is happening is that if by mistake the user introduces a character in place of a number, the loop repeats indefinitely because the program, when it get to the "cin" instruction, does not pauses to wait for a new input.
I've been reading and googling, etc. I've seen some things, but not a definite explanation of this. What is the appropriate way to mimic a C ternary operator using Python? Isn't there an exact proper way to do it? Any difference for using lambda functions? I'm sorry, but I've been searching and it's ambiguous to me how this should be handled. I would appreciate a person's help on this. I came up with this link, but I'm wondering if I'm missing something.[URL]...
So, is that it? In Dive Into Python, it's using the and-or trick. Well, if the above post is the full explanation,
how to overload the subscript operator ([]) for a list class?
Code:
template <typename T>
class list
{
public:
struct node
[Code]...
I have tryed out this operator on program:
Code:
#include <iostream.h>
#include <iomanip.h>
#include <fstream.h>
ofstream myfile;
[code]...
which definitly is not the same number. I guess somewhere in the convertion from double to char* ("<<") something is not right and what can i do to save these double numbers in an accurate manner in a file?
I would like to compare the nmlookup result of IP's stored in the file ips with a list of PC names stored in the file pcs.
Code:
for line in `cat "ips"`
do
[code]....
does the assignment operator copy all the members also for structures containing STL objects strings,vectors,vectors of vectors...)? I did try it on my platform,and it works that way (copying all the fields),but i was wondering if it is a standard behavior or not.
View 2 Replies View RelatedThis one is driving me crazy.
My .bashrc is set as:
if [ -d ~/.bashrc.d ]; then
for file in $(/bin/ls ~/.bashrc.d/); do
[code]....
My compiler won't find <new>. Since it's such a basic function, I'm a bit confused. Is <new> supposed to be in a file of its own? Where do I find it? And if it turns out to be missing on my computer, where can I find a <new> one? Or do you see anything else that I do wrong?
After some trying out, it seems I can't find stuff like iostream or any other basic stuff either. The compiler is prolly looking for them at the wrong place. Does anyone know how I change or add paths for the compiler to look in when using the "<>" operator?
Where is the perl module for programming with sockets?
View 4 Replies View RelatedSo I have a field in my table called "id" and this is the primary key for the table which is also configured to 'auto_increment' as show below:
Code:
mysql> describe users;
+------------+-------------+------+-----+---------+----------------+
[code]....
I just downloaded Tk-804.028 and try to install it (according to the README.linux) but I get:
> perl Makefile.PL
/opt/ActivePerl-5.10/bin/perl-static is installed in /opt/ActivePerl-5.10/lib okay
PPM for perl5.010001
Test Compiling config/perlrx.c
Test Compiling config/pmop.c
Test Compiling config/pregcomp2.c
[code]...
Any recommendations on what Perl tutorial to use?
View 1 Replies View RelatedI am taking an input from the user for free and Used capacity in a disk. I wish to convert Input entered in MBTB to GB and this is how i am doing it.
Code:
<some code>
print "Enter Total disk space";
$tot = <STDIN>;
convert($tot);
[code]...
how do i pass the value of conv[0] after conversion back to $tot or $use such that they contain only value which is in GB?
I really would like Perl Qt4 bindings. The best I could find is this:[URL]The problem is that the sources would not compile, and the RPMs are for 32-bit machines.Is there really no such thing as good Perl Qt4 bindings?
View 8 Replies View RelatedI am a newbie on linux and just searching everything about perl scripting and modules nearly 3-4 days. I need a perl script but one of not easy to find on searching google. Okay now I need a perl script which create or recreate (edit) id3 tags (artist, comment, album, year, cover) of mp3 files stored on my linux centos server. I installed MP3::Tag version 1.13 pearl module to my server. I Searched tutorials about how to use it, finally I get through reading id3 tag of mp3 file but not achieve to modify it or create a new id3tag.
These are the details:
I have a mp3 file called 1.mp3 this script will process that '1.mp3' file read its id3tag if there is one, than modify or create id3tag for it by my fix artist name for example:
'1.mp3' files id3 tag details are like this
Artist: Dj xx
Year:2010
Title:yyyyy
Comment:eerwer
Cover: x.jpg
Now via this perl script which uses MP3::TAG I will change it's
artist as YYY
Title:ttt
Comment:cool
Cover:t.jpg
these are gonna be my fixed values. I mean all '1.mp3' file will have same artist based on script value.
The reason of this script is I will share Dj podcasts on my server and Dj's would have upload their mp3's which has got different id3 tags and cover pics. etc. I want to create more organized podcasts of them by the way I would trigger this perl script via Cronjob.
How can I generate a md5 or sha-1 code with perl?
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