I want to know is there some more efficient way of passing a pointer to a local variable as a parameter to a function in x86 asm? Right now I have to move the base pointer to a temp register, subtract from the register and pass that, like this (assuming a local var at esp-4):
Code:
mov eax, ebp
sub eax, 4
push eax
Is there a better way?
I need to call functions that match an input string (if input str = "func1", call func1), so I have this:
Code:
#include <stdio.h>
#include <string.h>
void function_a(void) { printf("Function A
"); }
[Code].....
In the above example, the functions take no input arguments. Can they take a different number of arguments, for example, function_a(int), function_c(int, int), function_e(int, char, int)? How can I do that?
I have a file with around 1000 IP addresses in it and I need to be able to ssh into each one of them, run a single command, and then exit. I already know the ssh command I want to run and it looks like this:
Code:
shpass -p [password] ssh -p 10022 -o StrictHostKeyChecking=no root@[ip variable] 'reboot'
(I know shpass is not good to use and keys are the correct way but I don't have any other options in this scenario.) if these ip addresses were in a .csv file, by themselves with no other information, how would I create a script to do the above command to each ip until the end of the file?
I cannot for the life of me get this little (simple) script I wrote to work. Here is the entire script:
Code:
#!/bin/bash
ASPECT=`mediainfo $1 |grep "Display aspect ratio" |cut -d : -f 2`
HEIGHT=`echo "320 / $ASPECT" |bc`
SIZE=`echo 320x$HEIGHT`
[code]......
An input filename ($1) is fed into mediainfo, which by the use of grep and cut spits out a single number which is the aspect ratio. This is then divided by bc into 320, which gives the desired height dimension for the file that I want ffmpeg to create for me. Finally, ffmpeg runs using the calculated dimensions... Basically, it's the passing of the $ASPECT variable to bc that seems to fail. It looks like bc won't read the output from the mediainfo line... It always crashes out with:
Code:
(standard_in) 1: illegal character: ^M I've tried doing something even simpler like this to debug by just trying it to display the calculation on the screen:
Code:
#!/bin/bash
ASPECT=`mediainfo $1 |grep "Display aspect ratio" |cut -d : -f 2`
HEIGHT=`echo "320 / $ASPECT" |bc`
echo $HEIGHT
and it does the same, so it's definitely bc that won't accept the output from mediainfo.
I want to build on the code from /etc/apt/apt.conf.d/05etckeeper to work with Snapper, the new-in btrfs (et al) snapshot package.
Code: Select allDPkg::Pre-Invoke    { "if [ -x /usr/bin/etckeeper ]; then etckeeper pre-install; fi"; };
DPkg::Post-Invoke   { "if [ -x /usr/bin/etckeeper ]; then etckeeper post-install; fi"; };
The etckeeper code will work well as a template, but I need to pass a parameter between the pre- and post- instances. The parameter is obtained from the pre- invocation and passed to the post- invocation.I know that something similar to my quest is done with the 'pid' but how to do it in the 'standard' way. Happily there can't be multiple dpkg instances running concurrently (prevented by dpkg?) so I don't have to worry about that issue.
Q1. What is the 'standard' way of passing parameters about?
Code: Select allsnapper -c etc create -t pre -p   (which 'prints' the parameter (int) to pass to the following invocation)
snapper -c etc create -t post --pre-number <parameter> in place of the two etckeeper calls.
Q2. How do I pick up the 'printed' output of the 'pre' call? I think it's just a 'get' from the stream but perhaps I've missed something.?
I'm having some trouble this morning to send a SQL query to our Oracle DB server in PHP. When I try to pass my value "OF/110246801A01" as variable it tell's me "Warning: oci_bind_by_name(): ORA-01036: illegal variable name/number"
PHP Code:
$ociO ='OF/110246801A01';
$selectAllFieldsFromOf=oci_parse($conn,"SELECT*FROMMFGOPEWHEREMFGNUM_0LIKE':ociOf' ");
oci_bind_by_name($selectAllFieldsFromOf,":ociOf",$ociOf,15);
$resultQuery =oci_execute($selectAllFieldsFromOf);
if(!$resultQuery){
$e = oci_error($selectAllFieldsFromOf);
return trigger_error(htmlentities($e['message'],ENT_QUOTES),E_USER_ERROR);
[Code]....
Say, i have an imaginary std library function, which I want to call.
Code:
void std_lib_func(ObjectType *param);
Now in my c++ program, I have a main() function, and I will like to call a customized function (which will in turn call the std lib function) from the main function, as below:
Code:
int main()
{
ObjectType *aobj;
customized_func(aobj);
}
[Code]...
I tried the below but get an error that the std lib function is expecting a ObjectType* param, not aobj. How should I work this out.
Code:
void customized_func(ObjectType aobj)
How can I to pass a perl variable into html input tag? For example, If a have got a cgi script:
Quote:
use CGI;
use DBI;
my $owner = $cgi->param('owner');
[code]....
How can I to pass $owner variable?
I'm trying to implement an assert function similar to:[url]
However, I'm having trouble with file existence testing when the file name has a space in it.
I have distilled the problem down to the following:
This code works as expected, printing 'yes' if '~/test file' exists, and no if not.
Code:
However, this code gives an error.
Code:
The error:
Code:
Which tells me that it is splitting ["~/test file"] into ["~/test] and [file"]. Why? Is there a way around this?
Note that if you simply use a file path without a space, both cases work perfectly. Is this a BASH bug possibly? I just can't understand why the first would work, but the second wouldn't.
I want pass a variable at compile time.
for example in x.c
int global_var = POSITION;
How can I send this POSITION at compile time. ie like # make POSITION=10 Is it possible?
"While ; do ; done" is very convenient for SH coding. However sometimes you may be annoyed by your computed variable within the "while do done" type loop. What to do how to pass it out of the loop to the outside of the bash code? A solution is to write it into the /tmp or on the disk... and to call it back after. - not elegant... really not... Anyone would know a trick another alternative that would look nicer?
Code:
# Count file total size
TOTAL_SIZE=0
LISTOFFILES=`cat "$HOME/.fvwmoscfg/fvwmburnerlist.lst"`
echo "$LISTOFFILES" | while read i ; do
SIZE=`du -bs $i | cut -f 1`
TOTAL_SIZE=`expr $SIZE + $TOTAL_SIZE`
echo "$TOTAL_SIZE" > "$HOME/.fvwmoscfg/fvwmburnerlisttotalsize.lst"
done
TOTAL_SIZE=`cat $HOME/.fvwmoscfg/fvwmburnerlisttotalsize.lst`
echo "The total size of all files and folders is : $TOTAL_SIZE"
I am new to using 'pragma pack' and here is what I am running into :
Process A:
a.h -> defines a struct XYZ as PACKED and is of size 44bytes
a.c -> includes a.h and is able to print the size as 44 bytes.
Process B
b.c -> includes a.h,
b.c -> gets a message from process A, with struct XYZ in the message as data.
b.c -> After getting message, it is unable to print the elements of struct correctly. This is because the sizof (XYZ) in b.c is seen as 48 bytes.
I suspect, in b.c, the local variable of struct XYZ is being padded and not PACKED.
It's good that GCC support intel inline disassembly syntax, but it cannot even simply address local variables/parameters properly, making itself stupid and essentially useless, look at the following:
int myfunc(float f){
int x;
float fa[8];
asm(".intel_syntax noprefix
"
"mov eax, [x]
[Code]...
I am new to bash scripting. I want to know whether i can pass one variable to another. For example $1 represent argument1. Now if i want to get the argument 1 like USER="1" now i want $ of $USER to execute $1 so what should i do..
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View 14 Replies View Relatedi'm practicing in very basic c programs using the gcc compiler.I found that when i create two variables let's say
Code:
int a,b and Code: a=15;
b=3;
a=b;
b--;
then a equals 2.I thought that this isn't normal in C isn't it?I haven't had the time to read the gcc documentation yet...so i think it has something to do with my compiler's default settings.I use the
Code: gcc filename.c -o filename command to compile
Are all variables defined like pointers?
So the place where I'm having a problem is here:
Code:
typedef struct {
void **Mem_Chunk;
[code]...
What is the difference between *ptr++ and (*ptr)++. In my opinion the terminology is all over the place so if you could give an example it would be better.
View 8 Replies View Relatedi'm a bit stuck playing with the following class setup for glut. The actual issue is with the function pointers.Basically the following code is the opengl redbook cube example slightly modified.
View 2 Replies View RelatedI'm trying to figure out how to code for this specific type of instance - I want to use a hash and have the key be a reference to an array, and not use the key in the standard way of it being a scalar. Basically, I have a large output that I need to process line by line, and rather have access to it as an array than a big block in a scalar. For the big block hash as a scalar I would do -
Code:
foreach $CONTROLLER (<CONTROLLER_LIST>) {
$ALL_DISKS{$CONTROLLER} = `ssh -n <commands>`;
}
Now I know I could take the scalar and split it to another array after the fact like -
Code:
@TEMP_HOLD = split (/s+/,$ALL_DISKS{$CONTROLLER});
How would I code it that I would have access to the key information as an array and not a scalar? I know it needs to be a pointer and we're going to have -> in there somewhere, but not sure how to approach it. Some of the documentaiton I've been reading about referencing I've found a little confusing so far, and trying to figure out how to use them in context of what I'm working on.
I've seen all three uses:
type * pointer
type *pointer
type* pointer
Are these 3 forms essentially the same, i.e., is the spacing as used here a non-factor when declaring pointers?
I am trying to find a way to pull Node Pointers out of the model, for use in other areas of the program. The solution is probably simple but I haven't had any luck finding it.
Model for a QTreeView:
Code:
class testModel : public QAbstractItemModel
{
public:
testModel();
~testModel();
[code]....
I have the most strange problem ever in programming. I fork a process into a parent and a child. In every forked process i declare a pointer, malloc and define a different value for every pointer.When i printf the value and the address guess what? They both have the SAME ADDRESS but DIFFERENT values, as assigned..Here's the portion of my code:
pid = fork ();
switch (pid)
{
[code]....
I'm trying to read content of file to variable and use this variable in for loop. The problem is, when I have c++ comment style in file - /*. Spaces in line are also interpreted as separated lines.
For example:
Code:
Changing $files to "$files" eliminate these problems but causes that whole content of variable is treated as one string (one execution of loop).
I following structure
typedef struct
{
[code]...
my script has a variable which comes in the form +00.00 +0.00 -00.00 or -0.00 (the numbers can be any in that form) for any that have a + symbol I need to remove the +, but if it has a - symbol it needs to stay.
i need to make a new variable with the string from the old variable btut without any plus sign. I have tried a lot of different ways with no success, each thing I tried either left the + or removed the entire string. I think this should work but doesn't
foo=+12.40
bar=${foo#+}
I have a 10x2 matrix, I create said matrix and fill it one column with zeros and the other with ones, now when I print the matrix I get this:
column 1:
0,0,0,0,0,0,0,0,1,1
column 2:
1,1,1,1,1,1,1,1,1,1
The first two rows of the second column are being replaced into the last two rows of the first column, now I even checked in visual studio and it works fine there. A friend tried my code and he gets it even worse:
column 1:
0,0,0,0,1,1,1,1,1,1
column 2:
1,1,1,1,1,1,1,1,1,1
As far as I've seen it must be a problem with GCC, unfortunately I need to have this up and running in GCC no matter what.
[Code].....