removing leading and trailing whitespace from a string

[xytor]

Hi.
I want to remove all leading and trailing whitespace from a string, but i don't know how.

[redhead]

Is this in C ?

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


int main()
{
  char *str_trim, str[] = "   the string with leading and trailing spaces    ";
  int i, j, stop=0, length=strlen(str);
  /* create space for the copying */
  str_trim = (char*) malloc(length*sizeof(char));
  if(!str_trim)
    {
      printf("Error not enough heap space\n");
      return -1;
    }
  /* remove all leading whitespaces */
  for(i=0, j=0; str[i]; ++i)
    if(!stop && (str[i] == ' ' || str[i] == '\t'))
      ; /* skip it */
    else
      {/* copy everything after the leading spaces */
	stop=1;
	str_trim[j++] = str[i];
      }
  str_trim[j] = '\0';
  /* remove any tailing whitespace */
  length=strlen(str_trim) -1;
  for(;str_trim[length] == ' ' || str_trim[length] == '\t'; length--)
    ; /* just skoot on down there */
  /* eliminate any further whitespaces */
  str_trim[length +1] = '\0';
  printf("Results:\n");
  printf("\tOrrig string: \"%s\"\n", str);
  printf("\tTrim string: \"%s\"\n", str_trim);
  free(str_trim);
  return 0;
}

[xytor]

well, it works stand-alone but i need to integrate it into my program, which i am having trouble doing.

Pretty much, all i need to figure out is how to convert a string to an array of chars, and then an array of chars to a string, and i'm good

[redhead]

look at c_str like:

std::string foo("bar");
char str[] = foo.c_str();

And for the reverse it's just to look at the constructors to see:

std::string ret_str(str);