convert.c

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

#define MAXBUFFERSIZE 80

char convertChar(char ch)
{
  if(isupper(ch) != 0)
  {
    ch = tolower(ch);
  }
  else 
  {
    ch = toupper(ch);
  }
  return ch;
}
  


int main(int argc, char *argv[])
{
  char buffer[MAXBUFFERSIZE];
  int i;
  strcpy(buffer, argv[1]);
  for(i = 0; i < strlen(buffer); i++)
  {
    buffer[i] = convertChar(buffer[i]);
  }
  /*  buffer[charCount] = 0x00; null terminating */
  printf("%s\n", buffer);
}