스마트 컨트롤러

20150401

2015 스마트 콘트롤러/업무일지 2015. 4. 1. 17:46

==========================================================================================

S.C.

=======================================================================================

<C>

=typedef (:전처리 X => 끝에 반드시 ;): 별명

#include <stdio.h>

typedef unsigned int smart1;
typedef unsigned long smart2;

int main()
{
  unsigned int iNum1 = 100;
  unsigned long lNum1 = 1000;
  smart1 iNum2 = iNum1;
  smart2 lNum2 = lNum1;


  printf("iNum1 : [%d]\n", iNum1);
  printf("lNum1 : [%d]\n", lNum1);
  printf("iNum2 : [%d]\n", iNum2);
  printf("lNum2 : [%d]\n", lNum2);

  return 0;
}

=STRING LENGTH

-P434

#include <string.h>

typedef unsigned int size_t

size_t strlen(const char * s);

:문자열의 길이 반환

=STRING LENGTH(MY)

strlen => my_strlen 구현하기

=STRING COPY

char * strcpy(char * dest, const char * src);

char * strncpy(char * dest, const char * src, size_t n); // (최소 src 개수 / 최대 n개) 만큼

#include <stdio.h>
#include <string.h>

int main()
{
  char str1[20] = "1234567890";
  char str2[20];
  char str3[5];

  /**** case1****/
  strcpy(str2, str1);
  puts(str2);

  /**** case2****/
  strncpy(str3, str1, sizeof(str3));
  puts(str3);

  /**** case3****/
  strncpy(str3, str1, sizeof(str3)-1);
  str3[sizeof(str3)-1]=0;
  puts(str3);

  return 0;
}

#include <stdio.h>
#include <string.h>

int main()
{
  char cSrc[255];
  char cDst[5]="";

  scanf("%s", cSrc);
  strncpy(cDst, cSrc, sizeof(cDst));

  printf("cSrc : %s\n", cSrc);
  printf("cDst : %s\n", cDst);

  return 0;
}

<구현 - 1>

   while(1)
  {
    if(0 == uiCnt)
    {
      break;
    }

    if(0 == *cpSrc)
    {
      break;
    }

    *cpDst = *cpSrc;

    ++cpDst;
    ++cpSrc;
    --uiCnt;
  }

return cRet;
}

<구현-2>

#include <stdio.h>

char * my_strncpy(char * cpDst, const char * cpSrc, unsigned int uiCnt);

int main()
{
  char cSrc[255];
  char cDst[5]="";


  scanf("%s", cSrc);
  my_strncpy(cDst, cSrc, sizeof(cDst)-1);
  //strncpy(cDst, cSrc, sizeof(cDst)-1);

  printf("cSrc : %s\n", cSrc);
  printf("cDst : %s\n", cDst);

  return 0;
}

char * my_strncpy(char * cpDst, const char * cpSrc, unsigned int uiCnt)
{
  unsigned int uiCnt2 = 0;

  while(1)
  {
    if(uiCnt == uiCnt2)
    {
      break;
    }

    if(0 == *(cpSrc+uiCnt2))
    {
      break;
    }

    *(cpDst+uiCnt2) = *(cpSrc+uiCnt2);

    ++uiCnt2;
  }

  return cpDst;
}