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

These functions will modify the original buffer, so if dynamically allocated, the original pointer can be freed.

#include 

void rstrip(char *string)
{
  int l;
  if (!string)
    return;
  l = strlen(string) - 1;
  while (isspace(string[l]) && l >= 0)
    string[l--] = 0;
}

void lstrip(char *string)
{
  int i, l;
  if (!string)
    return;
  l = strlen(string);
  while (isspace(string[(i = 0)]))
    while(i++ < l)
      string[i-1] = string[i];
}

void strip(char *string)
{
  lstrip(string);
  rstrip(string);
}