memmove() is a C standard library function to copy a block of memory. It work even if the source and the destination overlap.
Questions tagged [memmove]
144 questions
1
vote
3 answers
Memmove in same pointer for deleting multiple whitespaces C
while this Code works:
char * k = "asd";
char * j = malloc(sizeof(char) * 3);
memmove(j,k,3);
printf("%s",j);
while code gives error:
char * k = "asd";
char * j = malloc(sizeof(char) * 3);
memmove(k,k+1,3);
printf("%s",k); // output should…
Batuhan Yaman
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1
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1 answer
malloc, free, and memmove inside a subfunction
I want to use a subfunction to copy a char array. it is like this:
void NSV_String_Copy (char *Source, char *Destination)
{
int len = strlen(Source);
if (*Destination != NULL)
free(Destination);
Destination = malloc(len + 1);
…
CaTx
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1
vote
2 answers
How to split a generic void array into parts.c
as a beginner in C, I am struggling with an obscure problem and because I couldn't find a solution to this particular problem I want to ask you the following:
Currently I am trying to understand void pointers and their arithmetic operations. I…
matzui
- 17
- 3
1
vote
6 answers
concatenate strings with memmove() in function
I want to concatenate two strings using a function that returns the resulting string. it would be something like this:
char *String_Concat (char *String_1, char *String_2)
{
char *StringResult;
//memmove String_1 to StringResult
…
CaTx
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1
vote
1 answer
Referencing memory that is overwritten by a memmove
I have the following code:
int** x;
// Add 4 int pointers to x - code ommitted
// Pop the first element
int* a = x[0];
memmove(&x[0], &x[1], sizeof(int*) * 3);
x = realloc(x, sizeof(int*) * 3);
// Some code that uses 'a' - ommitted
As per my…
thameera
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1 answer
Is there an equivalent of C++ std::copy in Rust?
The std::copy function in C++ copies elements pointed at by one iterator over the elements pointed at by another iterator. One important aspect of std::copy in C++ is that good implementations optimize by using std::memmove if the type of the…
kmky
- 783
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1
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2 answers
What is memmove() alternative when I know the overlapping side?
I want know what the fastest function for copy n bytes from *source to *destination, when
*destination = *source + k, and k is netural or zero.
The memcpy() function has undefind behavior for overlapping.
The memmove() function is not the best,…
user1134316
1
vote
1 answer
Problems with Memmove and SIGSEGV in C
I am having some issues with a memmove in C. As far as I can tell, both locations are valid memory addresses, I am able to print the contents of both memory locations before I perform the memmove, however as soon as I attempt to memmove, the…
paged90
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4 answers
Why can't I memmove std::string?
#include
#include
#include
using std::string;
string *arr_ptr;
int capacity;
void add() {
int old_capacity = capacity;
capacity <<= 1;
// double the capacity
string *tmp_ptr = new string[capacity];
…
Determinant
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1
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1 answer
memove a masked array - python
I have a numpy array which contains no data values. I mask those no data values so that they do not influence my calculations using:
array = numpy.ma.masked_values(array, options['ndv'], copy=False)
I then use memmove to get the numpy array…
Jzl5325
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0
votes
2 answers
Is there an "lseek" to memmove?
I have a buffer with n bytes, but I only want read in sizeof(something) bytes from byte 3, meaning I don't want to read in byte 1 and 2 from the buffer. For example...
For some buffer, byte 1 = 'a', byte 2 = 'b', byte 3 = uint64_t variable. What I…
Kobi
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1 answer
Can memmove accessing the contents of a FILE* and delete information?
Does memmove work on file pointer data?
I am trying to remove a line from a C file. I am trying to use memmove to make this more efficient than the internet's recommendation to create a duplicate file and overwrite it. I have debugged and I can't…
sasukenebe
- 21
- 3
0
votes
2 answers
Replacing a substring with another string in C
I am writing a code to replace all MACROS with its value.
If my macro MAX has a value 1000,
And in the code, it must be replaced with 1000.(I am assuming a case that if the MACROS are the first word in a line, then in that line MACROS will not we…
Muthu Ganapathy Nathan
- 3,199
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0
votes
1 answer
How to remove the first string element in array of string
Assuming I have this array of string
char* arr[] = {"Me", "you", "Now", NULL};
My aim is to remove "Me" so that the resultant array is:
arr = {"you", "Now", NULL};
Is there a way I can do this without running a for loop and store the element in a…
Pac
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0
votes
1 answer
Problem of "cyclic data " in x86_64 assembly code
I'm trying to write memmove in assembly:
the problem is that in my section data I've got two line : source and destination, and when I'm trying to pass 20 byte from source to destination while source got just 15 byte the 16th byte that pass from…
Doron Slomovits
- 27
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