Write function to achieve strcat/strlen/strcpy/strcmp

Write your own strcat strlen strcmp strcpy

strcat:

char *m_strcat(char *des,const char *src)

{
assert((des != NULL)&&(src != NULL));
char *add = des;
while(*des != ‘\0’)
++des;
while(*des++ = *src++)
;
return add;
}

strlen:

Int m_strlen(const char *str)
{
assert(str != NULL);
Int len=0;
while(*str != ‘\0)
{
++str;
++len;
}
return len;
}

strcpy:

char *m_strcpy(char *des,const char *str)
{
assert((des != NULL) && ( str != NULL))
char *add =des;
while((*des++ = *str++ ) != ‘\0’)
;
return add;
}

strcmp:

Int m_strcmp(const char *des,const char *str)
{
assert((des != NULL)&&(str !=NULL));
while((*des) == (*str))
{
If(*des == ‘\0’)
return 0;
++des;
++str;
}
return *des - *str;
}