sprint

sprintf

#include 

int main ()
{
  char buffer [50];
  int n, a=5, b=3;
  n=sprintf (buffer, "%d plus %d is %d", a, b, a+b);
  printf ("[%s] is a string %d chars long\n",buffer,n);
  return 0;
}

strchr

#include 
#include 

int main ()
{
  char str[] = "This is a sample string";
  char * pch;
  printf ("Looking for the 's' character in \"%s\"...\n",str);
  pch=strchr(str,'s');
  while (pch!=NULL)
  {
    printf ("found at %d\n",pch-str+1);
    pch=strchr(pch+1,'s');
  }
  return 0;
}

#define STRINGIFY_(M) #M
#define STRINGIFY(M) STRINGIFY_(M)
#include 
int main()
{
    //printf("%c\n",STRINGIFY(a));
    printf(STRINGIFY(X));
}

string num

#include 
#include 
#define DIGIT(n) ('0'+(n))
#define DIGIMOD(n,f) DIGIT((n)/(f) %10)
#define RJDIGIT(n,f)  ((n) >= (f) ? DIGIMOD(n,f):' ')
#define MINUSOR(n,alt) (n>0?(alt):(n=-n,'-'))
typedef unsigned char uint8_t;
char conv[8] = { 0 };
char* i8tostr3(const uint8_t xx)
{
    conv[4] = RJDIGIT(xx, 100);
    conv[5] = RJDIGIT(xx, 10);
    conv[6] = DIGIMOD(xx, 1);
    return &conv[4];
}
int main()
{
    //i8tostr3((uint8_t)643);
    printf("%s",i8tostr3((uint8_t)343));
    //printf("USA");



}

strstr

/* strstr example */
#include 
#include 

int main ()
{
  char str[] ="This is a simple string";
  char * pch;
  pch = strstr (str,"simple");
  printf("%s\n",pch);
  printf("%p\n",str);
  printf("%p\n",pch);

  strncpy (pch,"sample",4);
  puts (str);
  return 0;
}

strtol

#include       /* printf */
#include      /* strtol */

int main ()
{
  char szNumbers[] = "2001 60c0c0 -1101110100110100100000 0x6fffff";
  char * pEnd;
  long int li1, li2, li3, li4;
  li1 = strtol (szNumbers,&pEnd,10);
  printf("%s\n", pEnd);
  li2 = strtol (pEnd,&pEnd,10);
  printf("%s\n", pEnd);
  li3 = strtol (pEnd,&pEnd,2);
  printf("%s\n", pEnd);
  li4 = strtol (pEnd,NULL,0);
  printf("%s\n", pEnd);
  printf ("The decimal equivalents are: %ld, %ld, %ld and %ld.\n", li1, li2, li3, li4);
  return 0;
}

#include 
#include 

int main()
{
   char str[30] = "2030300   This is test";
   char *ptr;
   long ret;

   ret = strtol(str, &ptr, 10);
   printf("数字（无符号长整数）是 %ld\n", ret);
   printf("字符串部分是%s", ptr);

   return(0);
}