If I have two threads working on the same array but on different sections of the array, can they both write and read from it without locks and not have any sort of problem? If they only use completely different parts of the array always without affecting the other part?
View 3 RepliesI am trying to dynamically delete and add information into the array "blah"
Code:
int blahsize = 1;
char** blah = (char**) calloc(blahsize+1,sizeof(char*));
Adding information:
Code:
blah[1]=stuff1;
blah[2]=stuff2;
code....
I have trouble converting a short array to a char array
Code:
short pShort[4] = { 0x41, 0x42, 0x43, 0x44 };
How to convert this to a char array?
I'm writing a PHP program. I've encountered a problem; in the following code I try to pass $_POST['delete'] which is an array as the value of a hidden input to some form, but it doesn't do so.there's something wrong with converting PHP array into HTML array. I'm sure that $_POST['delete'] is not null and is a real array.
echo '<input type="hidden" name="delete[]" value="'.$_POST['delete'].'" />';
I want to create a "Shared Memory" in linux, then create multiple "Shared Objects" that can access to a Table for example; And one of them can write something into the Table and the other can access and read it, so that these operations can be handled by programmer! I'm using Ubuntu 9.04 and I've set it's runlevel at 3 (I have commandline environment now!) I've searched the Internet so much, but couldn't find a good sample code for this! I have no experience about it and need your help to introduce me a sample code about it and advise me how to compile and use it with "GCC"?!
View 6 Replies View Related(I am using vector() and matrix() functions from "Numerical recipes in C".)There are 100 numbers to be stored in 2D array of 10 rows and 10 columns.100 numbers are stored in a 1D array.I get "segmentation fault" at the line indicated in the segment of my code below:
Code:
:
:
#define size 100
#define nl 1
[code]....
I am going to write two or more programs that will take control of the same resources on Linux. What are the common methods/functions that can do locks/synchronizations in C?
View 1 Replies View RelatedI looked on the net for such function or example and didin't find anything, thus after having made one i guess it would be legitimate to drop it to see what others thinks of it.
#!/bin/bash
addelementtoarray()
{
local arrayname=$1
[code]....
locking mutex (phtread_t type) in a signal handler function (installed by function signal()) for Linux. It seems that if the mutex has been previously locked by another thread outside the signal handler function and then the signal handler function tries to lock it, the whole process hangs.
View 5 Replies View RelatedI have a linked list that two threads work on simultainiousley.The first thread is adding elements to end the linked list while the second is removing them from the front. Can this be done without a lock on the linked list head when elements are beingadded/removed?
I think this lock is causing a performance hit to my application. If there isnt any safe way without it then thats fine but just thought I would check.The first thread uses this fuction to add elements to the list. Full source here. [URL]
Code:
/* Lets add the new packet to the queue. */
pthread_mutex_lock(&workers[queuenum].queue.lock); // Grab lock on queue.
if (workers[queuenum].queue.qlen == 0){ // Check if any packets are in the queue.
[code]...
I wonder why arrays in the C programming language are pointers to the first element of the array, not the first element of the array itself?
View 14 Replies View RelatedThis array is supposed to contain 12 elements (names of the month) What I want to achieve is that depending on some user input (a number 1-12) a full name of one of the months will be displayed, eg.
Code:
scanf("%d", &month);
printf("The month is %c", months_names[month]);
I am trying to create an array containing all ASCII characters, how do I create one:
Code:
#!/bin/bash
CHARLIST=( a b c d e f g h i j k l m n o p q r s t u v w x y z
[code]...
I've got a problem...
a[0] = 22
echo $[a[0]]
echoes 22 - that works fine
[code]...
I have a text file from which i read a number of names with their lengths at the run-time.Now i want to created a char array having the length and name as already read from the text file at the run-time. There is no compilation involved. Every thing is happening at the run-time. I tried using STL like map along with malloc but i am unable to name an array at run-time. I can keep some type of mapping with previously created arrays
View 3 Replies View RelatedI've searched around and can't find out how to convert a string ( like "12345" ) into an int array ( x[ 5 ] = { 1, 2, 3, 4, 5 } ; ).
View 4 Replies View Relatedi am trying to represent alphabet into a array, and then i can count the frequency
for example
array[a]=0
array[b]=0
but i find the index of the array seems to be
array[1]=0
array[2]=0
I was try this way get the ascii for them, actually I have done this in java and it is simple.
something like this format
array[ascii{a}-ascii{a}]=0
array[ascii{b}-ascii{a}]=0
I have done a lot of searching , but cannot get what I want.'%d' "'$char" like this would not work.
how to sort the 2 dimensional array below by column 1 then by column 2?
22 55
2222 2230
33 66
44 58
222 240
[Code].....
this is a small part in my awk script. the input data is not in file, but it was manipulated in my script.
[code]...
I manage to write apr4sens into file,works fine.But how to write it into array,which I could later reshape and so on. I tryied like this
group=apr4sens. It doesn't work.
i have a loop which produces new value everytime it runs. i want to store the results in an array. how can i do dat??
loop is like:
a=0
declare v
while ((....))
do
v[$a]="$r"
let a=a+1
done
while doing this it is not treating v as array but as variable and it is overriding the value and old value is lost..i am using bash shell version 3.00.15
Here is statement.
$1[0]=0
$1 is an argument which is actually and array. In function we want to assign a value 0 of it's first content. But it's wrong way. Anybody know the right way to assign value in function by passing as argument.
Is it possible to have an array in Bash that can hold more than one value per item?
For example I would like an array like this:
Entry 1: apple, green
Entry 2: banana, yellow
And be able to call the fruit names and their colour in a list. Something like:
for fruit in "${array[@]}"
do
echo a $fruit is $colour
done
If that is possible, is there a limit to values per item? For example some entries in an array could be:
Entry 1: apple, green, round, pips, tree
Entry 2: banana, yellow, long, skin, tree
And I would like to pick out the values such as #3 being "round" and "long".
I believe I have unwanted ' characters left in a 9 element character array that are causing subsequent operations with it to fail. I see wildly differing views on the web on the proper way to flush 'em. It's clearly not as simple as it would appear at first sight. What's currently the best (or else "least deprecated") method?
View 5 Replies View RelatedCan you create a dynamic string array and using calloc(),realloc()?
Like:
Code:
string* x;
x = (string) calloc(x,sizeof(string));
With array in php. All I was having the following columns:
Code:
Now Like the Above there were more variables defined through script:
Code:
Now what the above code is doing is calculating average of above values from columns{1-?,4-?)..likewise
Say If I remove two Machine and calculate the avg.
Can I predefine constant array in c? with constants i do #define NAMEOFCONST value.is it possible to do this for an array? And if not I would like to know why. I suspect it has to do with memory handeling and pointers.
View 14 Replies View RelatedThe idea is to make a website to check the availability of domains and it works but its not pretty yet. Below is what i have till so far:
## this is the API from my domain registrar.
<?php $client = new SoapClient('http://api.sync.com/?wsdl');
## I have a search box that sends the request to this page
$var = $_GET ["s"];
## remove the most common subdomains from the request.
$var=eregi_replace("www.", "", $var);
$var=eregi_replace("mail.", "", $var);
$var=eregi_replace("ftp.", "", $var);
$var=eregi_replace("pop.", "", $var);
$var=eregi_replace("smtp.", "", $var);
## remove any TLD extension from the request.
$split = explode(".", $var);
$main = $split[0];
$arraysize = sizeof($split);
for ($x=1; $x<$arraysize; $x++) {
$tld .= "." . $split[$x];
}
## login to the API
$paramLogin = array('handle' => 'randall', 'password' => 'password');
## match the domain with any possible TLD
$varcom = $paramAvailDomain = array('sld' => $main, 'tld' => 'com');
$varnet = $paramAvailDomain = array('sld' => $main, 'tld' => 'net');
$varorg = $paramAvailDomain = array('sld' => $main, 'tld' => 'org');
$varbiz = $paramAvailDomain = array('sld' => $main, 'tld' => 'biz');
$varinfo = $paramAvailDomain = array('sld' => $main, 'tld' => 'info');
$vareu = $paramAvailDomain = array('sld' => $main, 'tld' => 'eu');
$varnl = $paramAvailDomain = array('sld' => $main, 'tld' => 'nl');
$varbe = $paramAvailDomain = array('sld' => $main, 'tld' => 'be');
$varde = $paramAvailDomain = array('sld' => $main, 'tld' => 'de');
$varcouk = $paramAvailDomain = array('sld' => $main, 'tld' => 'co.uk');
$varorguk = $paramAvailDomain = array('sld' => $main, 'tld' => 'org.uk');
$varname = $paramAvailDomain = array('sld' => $main, 'tld' => 'name');
$varmobi = $paramAvailDomain = array('sld' => $main, 'tld' => 'mobi');
$varin = $paramAvailDomain = array('sld' => $main, 'tld' => 'in');
$vartv = $paramAvailDomain = array('sld' => $main, 'tld' => 'tv');
$varcn = $paramAvailDomain = array('sld' => $main, 'tld' => 'cn');
$varws = $paramAvailDomain = array('sld' => $main, 'tld' => 'ws');
$varnu = $paramAvailDomain = array('sld' => $main, 'tld' => 'nu');
$varbz = $paramAvailDomain = array('sld' => $main, 'tld' => 'bz');
$varcc = $paramAvailDomain = array('sld' => $main, 'tld' => 'cc');
## this requests the domain.COM and domain.NET
$varcom;
$varnet;
?>
<div id="content">
## below prints the result
<?php
print "<html><body><pre>";
$result1 = $client->__soapCall('Login', $paramLogin);
echo "<b>Result Login:</b>
" . print_r($result1, true);
$result15 = $client->__soapCall('AvailabilityDomain', $varcom);
$resvarcom = var_dump($result15, true);
$result15 = $client->__soapCall('AvailabilityDomain', $varnet);
$resvarnet = var_dump($result15, true);
print "</pre></html>";
?>
<?php
## the returned array looks like this
Result Login:
Array
(
[code] => 200
[message] => Login succesful
)
array(3) {
["code"]=>
string(3) "200"
["message"]=>
string(20) "Domain not available"
["result"]=>
object(stdClass)#236 (1) {
["status"]=>
string(5) "TAKEN"
}
}
bool(true)
array(3) {
["code"]=>
string(3) "200"
["message"]=>
string(16) "Domain available"
["result"]=>
object(stdClass)#232 (1) {
["status"]=>
string(4) "FREE"
}
}
bool(true)
?>
## till so far it works
What I need to do is to make this ugly looking reply in to something more readable, basically if TAKEN print occupied and if free print its yours to grab. I have been struggling with the in_array function but i'm not getting anywhere close in getting it to work.
I was thinking about how to make a dynamic array in C, and I thought that it would be much better if it could accept any data type. Is this possible? Of course I thought about void pointers, but how do I store the actual data?
View 7 Replies View RelatedI'm trying access binary records that were created in Borland Delphi and stored in a SQL Server database (as a BLOB). What the heck is the syntax for accessing a two-D array in C#? Here's an example:
Code:
const
MAX_BOWLERS = 8;
gMAX_FRAMES = 40;
...
type
[code]...
I've successfully got a valid "GameRec" over to C#-land. I want to access array element "GameRec.Frames[iBowler, iFrame]".
How do I define a C# type "TFrames = Array[1..Max_Bowlers, 0..gMax_Frames] of TFrame;" so that I can do it?
I have never used multidimensional array for a long time so please consider this as a newbie question. I am editing a program that uses a 4 dimensional array and I think I'm losing track of the indexes.
day = 0 to 30
hour = 0 to 23
channel = 0 to 7
len = 0 to 63
unsigned char idx[day][channel][hour][len];
I have seen that the assignment to a string is
snprintf(idx[day][hour][channel], 64, "%s/%s", dayofmonth, hourofday);
Is this correct? Because when I access with a day argument, that day value goes into the hour part.