instr.c

来自「在linux下的聊天软件」· C语言 代码 · 共 65 行

/*
   instr.c
   
   By Bill Kendrick
   New Breed Software
   [e-mail]
   http://zippy.sonoma.edu/kendrick/

   June 27, 1996 - June 27, 1996
   Added #include <string.h> - Sept. 22, 1997

   Ported to NT by Patrick Stepp - Oct 1997
   [e-mail]

*/

#include <string.h>
#include "instr.h"

/* Returns the location within "string" that "word" begins, or -1. */

int instr(char * string, char * word)
{
  int i, far, started, found;
  
  found = 0;
  started = -1;
  far = 0;
  
  if ((strlen(word) != 0) && (strlen(word) <= strlen(string)))
    {
      for (i = 0; i < strlen(string); i++)
	{
	  if (string[i] == word[far])
	    {
	      
	      if (started == -1)
		started = i;
	      
	      far = far + 1;
	      if (far == strlen(word))
		{
		  found = 1;
		  far = 0;
		}
	    }
	  else
	    {
	      if (found == 0)
		{
		  far = 0;
		  started = -1;
		}
	    }
	}
    }
  
  /* Make sure we found the WHOLE word, not just the beginning! */
  
  if (found == 0)
    started = -1;
  
  return(started);
}