Programming :: How To Convert Negative Integer To Byte Array?
Oct 26, 2010
I need to convert an integer to a byte array of size 2 and vice versa. The code shown below works well for positive values but not for negative values. Also, using an array of size four makes the conversion works. However, I am limited to an array of size 2.
I'm learning C and trying to write a program to convert gigabyte into byte. It will take 50% of the value given and then convert that value into byte. But the problem is the output goes into minus / negative value. Like, if I enter 22, I get output: -2147483648.
Code:
#include <stdio.h> #include <math.h> main (int argc, char* argv[]) {
I am trying to learn assembly using nasm as assembler. I did not found example related to string operation. I had following example code,
global asm_strlen section .data section .bss section .text
[code].....
my problem is at highlighted line, I am not getting how to copy a byte into 4 byte reg. rather what is syntax of mov instruction to mov byte to WORD DWORD etc.
I got across a peculiar problem with memcpy.History:writing a code which do flash/Read functionality for SPI Parts.
Implementation: 1.memory map the Flash chip registers to userspace. - fine 2.Issue block read command 3.Just print the data I got, using the memory mapped address - fine I got the correct data. 4.Copy the data to a local buffer from memory mapped address using memcpy - FAIL
UPDATE: on SUSE 11.3 -32 bit the above code worked perfectly, but on SUSE 11.4 - 64bit , Ubantu, Fedora it failed. I am using gcc compiler obviously. I am using i386/x86_64 OS. Processor: Intel core 2 duo, SNB after step 4 , when I dump the data from local buffer every thing is FF.But step 4, if i implement byte by byte copy using assignment operator, it worked.is there any known bug with memcpy? am I missing anything?
I have a RAID 5 array, md0, with three full-disk (non-partitioned) members, sdb, sdc, and sdd. My computer will hang during the AHCI BIOS if AHCI is enabled instead of IDE, if these drives are plugged in. I believe it may be because I'm using the whole disk, and the AHCI BIOS expects an MBR to be on the drive (I don't know why it would care).
Is there a way to convert the array to use members sdb1, sdc1 and sdd1, partitioned MBR with 0xFD RAID partitions?
If I have a variable, say xvar, which can take both string and integer value and I want to perform an operation in following 2 conditions:1. Either xvar is null2. xvar equals 2[ -z "$xvar" ] || [ $xvar -eq 2 ] && <some-code>Doesn't seem to work if xvar takes string valuesI know that since I have no restriction on xvar, I can get away with string comparison in second test too, ie[ -z "$xvar" ] || [ "$xvar" = "2" ] && <some-code> But, 'Sams teach yourself shell script in 24 hrs' says that [ expr1 -eq expr2 ], if either is string, it assumes 0 valueIs it true
I'm trying to write a simple program that lists a menu and then asks you for your decision, and you can answer with a number or the name. However, I don't know how to add the second options (name).
I have a function that take char* I call this function in an array, and I need to pass the following:-i+" binomial" to be like "2 binomial" or whatever value of i value (i is an integer) it is pretty easy to be done in java, but how to concatenate an integer with a string and get char* or string to pass to a new function.If you missed me i just need to get the following :string =integer + string
I have a file in which contains one line with a lot floating points.In the very first place and some times in the downstream, there are a few integers, surrounded by blank spaces.1 1.02-4 1.03-5 544 1.04-1 65 2.98-1 5.78-10 3.45-2 etc etc.I aim to split the file in more files each of them containing an integer and the following floatings until the next integer.
In a c program the value of an integer variable is changing rapidly. I have to get the value of that variable at a particular instant from another program. How can i do it without using a file?
When i tried with extern variable as
I execute the both .c file from 2 terminals but got only value 0 printed for both var_a and var_b all the time .
I have a java compiler and Im using a double intiger called Experience and when compiled and run the double intiger does not hold intiger values that are mathameticle. Like 1.5 - 1.4 will equal .100000000000000000009 and 5/3 will equal 1.0. and 1.5x 1.4 doesnt equal 2.1. Is there something I am doing wrong with double intigers? Is it the compilers fault? Could it be something thats wrong with my computer and the compilers I am using are not tat fault? Anyways double 1.5 + 1.4 does equal 2.9 so.
I want to print a single digit integer on to the screen using the int 0x80. I have loaded the number in the ecx(=5, say), size in edx (=4, lenght) and eax (=4) ebx (=1). I've added 48 to the contents of ecx, and then calling int 0x80, I thought should print 5 on the screen.
However it does not print anything. also gives no errors. I checked the contents of the ecx reg (gdb), it has 53.
A snippet showing the this will be great. I've seen snippets using the c library (printf), but I want to see how it is done using int 0x80.
In words, AND the byte at memory location 45 with immediate value 03. As reports "Ambiguous operand size for and". How could I code the instruction such that as understands my intention?
john: .byte 45 and byte[john],03 gives the same error.
I'm trying to write an extension to PHP which means coding in C. I'm really really rusty at C coding and was never very good at it.
Can anyone propose an efficient, safe, and [hopefully] future-proof way of reversing a double? Keep in mind that it should work on as many systems as possible and on 32- and 64-bit systems (and on ???-bit systems in the future?). Will the size of a 'double' ever change or will it always be 8 bytes?
I've tried this and it doesn't work...the compiler complains about "invalid operands to binary" because I'm trying bitwise shiftw on a non-integer.
I thought there exists a built-in function that gives total size of a list object in byte. So using the function produces 1 for a1, 3 for a2. I haven't found such function or module yet.
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.
(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:
I 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
I have a assignment relating to barcode reading.Let say i have to enter the 13 digit barcode with hyphen e.g "Enter barcode:123-46574-48847" using scanf.Once thats done how do i extract the values without the hyphene.g using printf "1234657448847". No arrays No strings and No function is allowed.No while loop is allowedThe lecturer's tip was to treat "-" as negative and not hyphen.
I have tried to learn how 64bit asm (nasm in my case) works and found, among the many disparate pieces of info on the net, a few vague inferences that floating point registers can be used for other purposes than what they are intended for, example: "64-bit Linux allows up to fourteen parameters to be transferred in registers (6 integer and 8 floating point)." This would be fantastic for string operations/manipulation (I have never used asm for floating-point operations), can anyone shed a bit of light?