Class Reference string.h

Byte-wise memory functions for C++ macros. More...

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Detailed Description

Byte-wise memory functions for C++ macros. Load with #include <string.h> or #include <cstring> (same plugin). Available from LayoutEditor 20260918.

Do not write #include <string> for this plugin. That name is the C++ string header and is not mapped here. Text in macros is the LayoutEditor string class (length(), +, …).

These four functions work on raw bytes, not on “C strings with a terminating zero” in the usual library sense. strcpy and strcat are not bound — concatenate with string (a = a + b).

memcmp on two LayoutEditor strings compares their UTF-8 bytes.

memcpy / memmove / memset need a real memory address (void *). That is an advanced topic. For comparing text, use memcmp or string operators (==).

Example

#include <string.h>

int main(){
    if (memcmp("abc", "abc", 3) != 0) return 1;
    if (memcmp("abc", "abd", 3) == 0) return 1;
    cout("memcmp ok\n");
}

Member Function Documentation

void * string.h::memcpy(void *dst, void *src, int n)

Copies n bytes from src to dst. The two regions must not overlap. If they might overlap, use memmove.

Parameters:

• dst — destination address.
• src — source address.
• n (int) — number of bytes. If n ≤ 0, nothing is copied.

Returns: dst (the same pointer you passed in). If dst or src is empty, returns dst without copying.

void * string.h::memmove(void *dst, void *src, int n)

Copies n bytes from src to dst. Overlap is allowed (the function copies in a safe order).

Parameters:

• dst — destination address.
• src — source address.
• n (int) — number of bytes.

Returns: dst.

void * string.h::memset(void *dst, int c, int n)

Fills n bytes at dst with the byte value c (only the lowest 8 bits of c are used). memset(p, 0, n) is a common way to zero memory.

Parameters:

• dst — destination address.
• c (int) — byte value (0 … 255).
• n (int) — number of bytes.

Returns: dst.

int string.h::memcmp(void *a, void *b, int n)

Compares n bytes at a with n bytes at b. On two string values this compares the text byte by byte.

Parameters:

• a — first block or string.
• b — second block or string.
• n (int) — how many bytes to compare. If n ≤ 0, the result is 0.

Returns: int

• 0 if the n bytes are equal
• negative if a is less than b at the first difference
• positive if a is greater than b at the first difference

memcmp("abc", "abd", 3) is not 0. memcmp("abc", "abc", 3) is 0.

Python: compare str / bytes with == and slices. This include is for C++ macros only.