/* -------------------------------------------------------------------------
** 
** str.c - implementacao das funcoes para manipulacao de strings.
** 
** CURSO DE PROGRAMACAO - II
**
** Prof. Márcio Santi.
** -------------------------------------------------------------------------
**
*/
#include <ctype.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

/* -------------------------------------------------------------------------
** Funcoes locais:
*/

/* -------------------------------------------------------------------------
** Funcoes publicas:
*/

/* =============================== StrPut =============================== */

void StrPut(char *s)
{
  int i;

  for (i = 0; s[i] != '\0'; i++) putchar(s[i]);
}

/* =============================== StrGet =============================== */

int StrGet(int lim, char *s)
{
  int i,c;
  int l = lim - 1;

  for (i = 0; i < l; i++)
  {
    c = getchar( );
    
    if (c == EOF || c == '\n') break;

    s[i] = c;
  }
  s[i] = '\0';

  return(i);
}

/* =============================== StrLen =============================== */

int StrLen(char *s)
{
  int i;

  for (i = 0; s[i] != '\0'; i++);

  return(i);
}

/* =============================== StrCpy =============================== */

void StrCpy(char *s, char *t)
{
  int i;

  for (i = 0; t[i] != '\0'; i++) s[i] = t[i];

  s[i] = '\0';
}

/* =============================== StrCat =============================== */

void StrCat(char *s, char *t)
{
  int i,j;

  for (i = StrLen(s), j = 0; t[j] != '\0'; i++, j++) s[i] = t[j];

  s[i] = '\0';
}

/* =============================== StrCmp =============================== */

int StrCmp(char *s, char *t)
{
  int i;

  /* Percorre as strings enquanto elas forem iguais.
  */
  for (i = 0; s[i] == t[i]; i++)
  {
    /* Se as strings chegaram ao fim entao elas sao iguais.
    */
    if (s[i] == '\0' || t[i] == '\0') return(0);
  }

  /* Retorna a diferenca entre os caracteres de cada string.
  */
  return(s[i] - t[i]);
}

/* =============================== StrFnd =============================== */

int StrFnd(char *s, char *t)
{
  int i,j,k;

  /* Verifica se as strings sao validas.
  */
  if (s[0] == '\0' || t[0] == '\0') return(0);

  /* Percorre a string "s" ate' o seu final.
  */
  for (i = 0; s[i] != '\0'; i++)
  {
    /* Percorre as strings "s" e "t" enquanto "t" pertencer a "s".
    */
    for (j = 0, k = i; (t[j] != '\0') && (t[j] == s[k]); j++, k++);

    /* Se chegou ao fim de "t" entao toda a string pertence a "s".
    */
    if (t[j] == '\0') return(1);
  }

  return(0);
}

/* =============================== StrUpp =============================== */

void StrUpp(char *s)
{
  int i;

  for (i = 0; s[i] != '\0'; i++) s[i] = toupper(s[i]);

  s[i] = '\0';
}

/* =============================== StrLow =============================== */

void StrLow(char *s)
{
  int i;

  for (i = 0; s[i] != '\0'; i++) s[i] = tolower(s[i]);

  s[i] = '\0';
}

/* =============================== StrAlc =============================== */

char *StrAlc(int n)
{
  char *s = (char *) calloc(n, sizeof(char));

  if (s == NULL)
  {
    printf("\nMemoria insuficiente na funcao StrAlc.\n");
    exit(1);
  }

  return(s);
}

/* =============================== StrDup =============================== */

char *StrDup(char *s)
{
  int  i,n;
  char *t;

  /* Aloca memoria para a nova string (inclui o '\0').
  */
  n = StrLen(s) + 1;
  t = StrAlc(n);
  
  /* Copia os caracteres (inclusive o '\0').
  */
  for (i = 0; i < n; i++) t[i] = s[i];

  return(t);
}