sort_char.c

/*
  [sort_char.c]
Author : AlexZ ( alessandro.suglia@gmail.com )
Date : 30/09/2011 07:57 PM

Simple program which takes an undefined
length string and sort alphabetically each
of its char.

*/

/* <------------Header Functions Declaration -----------------> */

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

/* <-----------Functions Declarations -----------------------> */

char *sort_char( const char * );
int count_argv( char *argv[], int argc );
char *strcat_argv( char *s, int len, char *argv[], int argc );

/* <------------- main.c ------------------------------------> */
int main(int argc, char *argv[] )
{
  char *s = NULL;
  int len = 0; /* variable which holds the entire length of the argument passed through the command line*/

  if ( argc < 2 ) /* Too few arguments, something was wrong */
    {
      perror("<<<<USAGE<<<<< : ./ord_char 'word'\nTry again passing a string\n");
      exit(-1);

    }

  len = count_argv(argv, argc); /* call to the function count_argv */
  s = strcat_argv(s, len, argv, argc); /* call to the function strcat_argv */

  if ( !(s) ) /* Memory Allocation test */
    {
      perror("Malloc error : FATAL ERROR!\n");
      exit(-1);
    }
  s = sort_char(s); /* Call ord_char function */

  printf("SORTED STRING %s : %s\n", argv[1],s);

  return EXIT_SUCCESS;

}
/* Count the number of argument that were passed through the command line */
int count_argv( char *argv[], int argc)
{
  int i;
  int len = 0;

  for ( i = 1; i < argc; i++ )
    len += strlen(argv[i]);

  return len;

}
/* Concatenates the command line arguments in a single string */
char *strcat_argv( char *s, int len, char *argv[], int argc )
{
  int i;

  s = (char*)malloc(len * sizeof(char));
  if ( !(s) )
    {
      perror("Malloc error : FATAL ERROR!\n");
      exit(-1);
    }
  for ( i = 1; i < argc; i++ )
    strcat(s, argv[i]);

  return s;
}
/* Sorts alphabetically each string's char */
char *sort_char( const char *s )
{
  int i;
  int high = strlen(s);
  char *str;
  char c;

  str = (char*)malloc(high * sizeof(char));
  if ( !(str) )
    {
      perror("MALLOC ERROR : Fatal!\n");
      exit(-1);
    }
  strcpy(str, s);
  /* Simple bubble sort implementation */
  while ( high > 1 )
    {
      for ( i = 0; i < high-1; i++ )
    if ( str[i] > str[i+1] )
      {
        c = str[i];
        str[i] = str[i+1];
        str[i+1] = c;

      }

      high--;


    }

  return str;
}