kstring

This module has 18 functions that are defined as follows:

void* kmemcpy(void *restrict destination, const void *restrict source, size_t num);

This function copies memory of size num from memory location source to the destination. Source and destination memory cannot overlap.

Example Usage:

#include "kstring.h"
#include "kstdio.h"
#include "stdint.h"

int main(void) {
    terminal_initialize();
    const char src[13] = "Hello world!";
    char dest[13];
    kmemcpy(dest, src, kstrlen(src)+1);
    kprintf(dest);
    return 0;
}

Output:

Hello world!

void* kmemmove(void* destination, const void* source, size_t num);

This function copies memory of size num from memory location source to the destination. Source and destination memory can overlap.

Example Usage:

#include "kstring.h"
#include "kstdio.h"
#include "stdint.h"

int main(void) {
    terminal_initialize();
    char src[] = "Hello world!";
    kmemmove(src+4, src+2, 4);
    kprintf(src);
    return 0;
}

Output:

Hellllo rld!

void* kmemchr(void* ptr, int32_t value, size_t num);

This function finds the first occurrence of value in memory of size num.

Example Usage:

#include "kstring.h"
#include "kstdio.h"
#include "stdint.h"

int main(void) {
    terminal_initialize();
    unsigned char source_buffer[] = {0xDE, 0xAD, 0xBE, 0xEF, 0x70, 0x09, 0x02, 0x03};
    const unsigned char \*const result = kmemchr((unsigned char\*) source_buffer, 0x09, sizeof(source_buffer));
    kprintf("%d", (result == &buffer[5]));
    return 0;
}

Output:

1

int32_t kmemcmp(const void* ptr1, const void* ptr2, size_t num);

This function compares two blocks of memory of size num.

Example Usage:

#include "kstring.h"
#include "kstdio.h"
#include "stdint.h"

int main(void) {
    terminal_initialize();
    const char \*const str1 = "abc";
    const char \*const str2 = "cde";
    const int32_t result = kmemcmp(str1, str2, kstrlen(str1));
    kprintf("%d", result);
    return 0;
}

Output:

-1

void* kmemset(void* ptr, int32_t value, size_t num);

This function sets memory of size num to value.

Example Usage:

#include "kstring.h"
#include "kstdio.h"
#include "stdint.h"

int main(void) {
    terminal_initialize();
    uint32_t buffer[] = {0xDEAD, 0xBEEF, 0x10, 0x54, 0x97, 0x83, 0x12, 0x10};
    const uint32_t \*const result = kmemset(buffer, 0xFF, sizeof(buffer));
    for(int32_t i = 0; i < sizeof(buffer)/sizeof(uint32_t); ++i) {
        kprintf("%x\n", buffer[i]);
    }
    return 0;
}

Output:

ffffffff ffffffff ffffffff ffffffff ffffffff ffffffff ffffffff ffffffff

char* kstrcat(char* destination, const char* source);

This function concatenates two strings (without bounds checking).

Example Usage:

#include "kstring.h"
#include "kstdio.h"
#include "stdint.h"

int main(void) {
    terminal_initialize();
    char buffer[32] = "abc";
    const char \*const result = kstrcat(buffer, "cdef");
    kprintf(result);
    return 0;
}

Output:

abccdef

char* kstrncat(char* destination, const char* source, size_t num);

This function concatenates two strings (with bounds checking).

Example Usage:

#include "kstring.h"
#include "kstdio.h"
#include "stdint.h"

int main(void) {
    terminal_initialize();
    char buffer[6] = "abc";
    const char \*const result = kstrncat(buffer, "cdef", sizeof(buffer)/sizeof(char));
    kprintf(result);
    return 0;
}

Output:

abccd

char* kstrchr(char* str, int32_t character);

This function finds the first occurrence of character in string str (searching from start of string).

Example Usage:

#include "kstring.h"
#include "kstdio.h"
#include "stdint.h"

int main(void) {
    terminal_initialize();
    char source[] = "aba";
    const char c = 'a';
    const char \*const expected = source;
    const char \*const result = kstrchr(source, c);
    kprintf("%d", (result == expected));
    return 0;
}

Output:

1

char* kstrrchr(char* str, int32_t character);

This function finds the first occurrence of character in string str (searching from end of string).

Example Usage:

#include "kstring.h"
#include "kstdio.h"
#include "stdint.h"

int main(void) {
    terminal_initialize();
    char source[] = "aba";
    const char c = 'a';
    const char \*const expected = source + 2;
    const char \*const result = kstrrchr(source, c);
    kprintf("%d", (result == expected));
    return 0;
}

Output:

1