How do I trim leading/trailing whitespace in a standard way?

Question

Is there a clean, preferably standard method of trimming leading and trailing whitespace from a string in C? I\'d roll my own, but I would think this is a common problem wit

Answer 1

To trim my strings from the both sides I use the oldie but the gooody ;) It can trim anything with ascii less than a space, meaning that the control chars will be trimmed also !

char *trimAll(char *strData)
{
  unsigned int L = strlen(strData);
  if(L > 0){ L--; }else{ return strData; }
  size_t S = 0, E = L;
  while((!(strData[S] > ' ') || !(strData[E] > ' ')) && (S >= 0) && (S <= L) && (E >= 0) && (E <= L))
  {
    if(strData[S] <= ' '){ S++; }
    if(strData[E] <= ' '){ E--; }
  }
  if(S == 0 && E == L){ return strData; } // Nothing to be done
  if((S >= 0) && (S <= L) && (E >= 0) && (E <= L)){
    L = E - S + 1;
    memmove(strData,&strData[S],L); strData[L] = '\0';
  }else{ strData[0] = '\0'; }
  return strData;
}