os_kernel_lab/labcodes_answer/lab8_result/kern/libs/string.c

#include <string.h>
#include <kmalloc.h>

char *
strdup(const char *src) {
    char *dst;
    size_t len = strlen(src);
    if ((dst = kmalloc(len + 1)) != NULL) {
        memcpy(dst, src, len);
        dst[len] = '\0';
    }
    return dst;
}

char *
stradd(const char *src1, const char *src2) {
    char *ret, *dst;
    size_t len1 = strlen(src1), len2 = strlen(src2);
    if ((ret = dst = kmalloc(len1 + len2 + 1)) != NULL) {
        memcpy(dst, src1, len1), dst += len1;
        memcpy(dst, src2, len2), dst += len2;
        *dst = '\0';
    }
    return ret;
}