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Questions tagged [strcpy]

The C standard library function, "strcpy()," is used to copy non-overlapping, null-terminated strings. It is also defined as "std::strcpy()" in the C++ standard library.

Used to copy null-terminated, non-overlapping strings, it is defined in the <string.h> standard header. It is also defined in the C++ standard library in the <cstring> header.

Documentation for C strcpy.

Documentation for C++ std::strcpy.

947 questions
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Why do i gett warnings by using strcpy_s and strcat_s?

I programmed an example on my Win64 PC with code:blocks using strcpy_s and strcat_s. The program works, but I get the warning messages "warning: implicit declaration of function 'strcpy_s' for strc_s and strcat_s respectively. The compiler settings…
Heimo
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Why does strncpy() produce garbage when the dest is smaller than the src but large enough to fit the wanted substring of src?

I tried to limit the number of n bytes copied to dest (here str1) by using strncpy(). The dest is big enough for the n bytes, but the output produced garbage when dest is smaller than the source (here argv[1]). This looks different, when i make dest…
Coder
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Updating the string using function in c

I have written following c code to update the char array rb but it is printing garbage value #include void update(char* buff){ char word[] = "HII_O"; buff = word; return; } int main(){ char rb[6]; update(rb); rb[5]…
ancad ancad
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C6387 for memcpy, strcpy and strcpy_s

It seems that I cannot shake the C6387 warning. typedef struct HashBind{ char* cKeyIdentifier; void* vValue; } HashBind; .... HashBind* strNewBind = malloc(sizeof(HashBind)); strNewBind -> cKeyIdentifier = (char*)…
user10817807
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How to properly implement strcpy in c?

According to this: strcpy vs strdup, strcpy could be implemented with a loop, they used this while(*ptr2++ = *ptr1++). I have tried to do similar: #include #include int main(){ char *des = malloc(10); for(char…
milanHrabos
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realloc memory in string array in C

I'm trying to satisfy valgrind and come up with a nice implementation, but I'm coming across a snag. Essentially what I'm trying to do is reduce two strings in an array to one. Let's say arr contains { "One", "Two", "Three" } And that the memory…
Rio
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C - memcpy with char * with length greater than source string length

I have the following code in C now int length = 50 char *target_str = (char*) malloc(length); char *source_str = read_string_from_somewhere() // read a string from somewhere // with length, say…
abisheksampath
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What defines strscpy in C?

From this video on youtube by Kees Cook from linux.conf.au 2019 he mentions strscpy as being preferred but generally doing what users want (less NUL-padding). However, he doesn't say what defines this (spec or header), Slide from the video, I…
Evan Carroll
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Do strncpy/memcpy/memmove copy the data byte by byte or in another efficiently way?

As we know, in a multi-bytes word computer such as x86/x86_64, it is more efficiently to copy/move a big bulk of memory word by word (4 or 8 bytes per step), than to do so byte by byte. I'm curious about which way would strncpy/memcpy/memmove do…
Leon
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how to use strncpy correctly?

I know strncpy is a safer version of strcpy as said here. However, when I want to copy from src to dst and dst is not a clean buffer, I get unwanted results, which can be avoided by strcpy: char *p = "123"; char a[10] =…
CIsForCookies
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Why does C's strcpy fail with doubly indexed arrays?

The following code seems to segfault and I cannot figure out why. #include static char src[] = "aaa"; int main() { char* target[2] = {"cccc","bbbbbbbbbb"}; strcpy(target[1],src); return 0; }
confusedDespiteKnowingBetter
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C: Writing 4 bytes into a region of size 3 overflows the destination?

My simple C program is as follows. Initially, I've defined variable buf1 with 3 char. I don't have any problem with 2 char such as AB or XY user@linux:~/c# cat buff.c; gcc buff.c -o buff; echo -e '\n'; ./buff #include #include…
user9013730
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About strcpy() in TCPL

I am reading The C Programming Language, and when it gets to Character Pointers and Functions (5.5) I get a problem. In 5.5, the authors showed four versions of strcpy(). My problem lies in the version 3: /*strcpy: copy t to s; pointer version…
1MinLeft
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char pointers and strcpy in C

First let me start saying I have read all the questions related to this subject and can't find a solution for my problem. All the answers seem to be to stop using pointers and chars(which I need to do) or are about other structures. I need to…
M.O.
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strcpy() and arrays of strings

I need to store the input from a user into an array of strings. #include #include #include char *history[10] = {0}; int main (void) { char input[256]; input = "input"; strcpy(history[0], input); …
Spencer
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