(C) memcpy

function for copying one buffer to another.

You can also use it to copy a ?struct to a char array:

include <stdio.h>

include <assert.h>


typedef struct
{
  char name[12]; /* No terminator */
  char date[8];  /* No terminator */
  char age[2];   /* No terminator */
} MyStruct;
int main(int argc, char* argv[])
{
  /* Create a struct */
  MyStruct m;
  /* Create an array */
  char a[sizeof(MyStruct) + 1] = { '\0' };
  {
    /* Some compile-time asserts */
    const char temp1[ (sizeof(m.name  ) == 12 ? 1 : 0) ] = { '\0' };
    const char temp2[ (sizeof(m.date  ) ==  8 ? 1 : 0) ] = { '\0' };
    const char temp3[ (sizeof(m.age   ) ==  2 ? 1 : 0) ] = { '\0' };
    const char temp4[ (sizeof(MyStruct) == 22 ? 1 : 0) ] = { '\0' };
  }
  /* Initialize the struct */
  memcpy(m.name,"Bilderbikkel",sizeof(m.name)); /* No terminator */
  memcpy(m.date,"20070509",sizeof(m.date));     /* No terminator */
  memcpy(m.age,"26",sizeof(m.age));             /* No terminator */
  /* Copy the struct to the array */
  memcpy(a,&m,sizeof(MyStruct));
  /* Add a terminator to the array */
  a[sizeof(MyStruct)] = '\0';
  /* print the array */
  printf("'%s'",a);
  /* Finished ! */
  return 0;
}

'memcpy' links

last edited (May 9, 2007) by bilderbikkel, Number of views: 2939, Current Rev: 2 (Diff)

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