Thread: String editor for a sentence inputted by a user - any suggestions or ideas?

To Prelude,

Sorry if it's only now I've replied to your post - been studying over the source lines you gave me. By the way, there are some things I wish to know about them...

- What are the advantages of using the function "fgets" over "gets"? (as in the case of this program)

- Could you please explain how does the function "memmove" act on this line...

Code:

memmove ( match, match + len, len );

If you were to make your own version of the 'memmove' function, what would it look like? (Could you also please include a pseudocode of it?)

- If I were to make my own version of the function strstr, would it look like the one below?

Code:

//Program to find an input substring in an input main string

void main()
{
 int i=0;
 int j=0;
 int k=0;
 int l=0;
 int k1=0;
 char a[80],b[80];

 clrscr();
 printf("Enter main string:- ");
 gets(a);
 printf("Enter sub-string:-");
 gets(b);

 l=strlen(b);
 while (a[i]!=EOF) do
       {
        if (a[i]==b[j])
           {
            i++;
   	    j++;
   	    k1=1;
           } 
         else
           {
   	    if (k1==1)
   	       {
    		j=0;
    		k1=0;
   	       }
   	     else
               i++;
           }
       }

  if (k==1)
     {
      printf("The given sub-string is present in the main string.");
     }
   else
     {
      if (k==0)
      printf("The given sub-string is not present in the main string.");
     }
 getch();
}

And here's my interpretation of the ideas you gave me

Code:

//Edits a string


#include<stdio.h>
#include<stdlib.h>
#include<conio.h>
#include<string.h>
#include<alloc.h>
#include<mem.h>



//All the functions to use
//Searches for the string
char Find(char main_str, int len)
{
 char search_str;	//The string to delete
 char *match;		//Contains the string that matches the one to search
 
 printf("String to find:");
 if ( fgets ( search_str, sizeof search_str, stdin ) != NULL ) 
    {
     char *match = strstr ( main_str );
    
     if ( match != NULL )
        printf ( " \"%s\" found at position %d", search_str, match - main_str );
      else
        printf ("The word you want to search does not exist");
    }
 getch();
 return new_str;
}


//Deletes the string
char Erase(char main_str, int len)
{
 char del_str;		//The string to delete
 char *del_match;	//Contains the string that matches the one to delete
 char new_str;		//Displays the new string
 int delstr_len;	//length of the string to delete

 printf("String to delete:  ");
 if ( fgets ( search_str, sizeof search_str, stdin ) != NULL ) 
    {
     del_match = strstr (main_str);
     if ( del_match != NULL ) 
        {
         delstr_len = strlen ( search_str );
         new_str = memmove ( del_match, del_match + len, len );
         printf ("New source: %s \n", new_str);
        }
      else
        printf ("The word you want to delete does not exist");
    }
 getch();
 return new_str;
}


//Inserts the string - the one you wanted me to try coding on
char Insert(char main_str,int len)
{
 int sub_len, total_len;	//variables to use in this function

 printf("String to insert: ");
 fgets(sub_str, sizeof sub_str, stdin);	// gets the string from the user
 
 sub_len = strlen (sub_str);		//gets the length of the string to insert
 
 printf("\nPosition of insertion>   ");
 scanf("%d", &pos);			//gets the position as to where to place the string on the main string
 
 total_len = len + sub_len;		//gets the total length of the two strings to use...
 
 char newstring[total_len];		//...as the basis for the length of this array that will hold both of them
 
  // from the starting point of insertion on main_str up to the end of sub_str, insert subtring while incrementing forward
 	for (i=main_str[pos]; i<sub_str[n-1]; i++)	
						   //does "sub_str[n-1]" access the tail end of sub_str?

     newstring = strcat (main_str, sub_str);	//starts inserting the sub_str into main_str using the strcat function
 printf("New source:  %s \n",newstring);	//prints out the string
 
 getch();
 return newstring;
}



//the program proper
void main(void)
{
 char main_str;		//the first string that the user types in
 int len;		//length of main string
 int choice;		//menu choice number

 do
  {
   do
    {		//the menu proper
     clrscr();
     printf("Please type in a sentence:  ");
     fgets(main_str, sizeof main_str, stdin);    //gets main_str
     len = strlen (main_str);       //gets the length of main_str

     printf ("\n");
     printf("[1] Find \n");
     printf("[2] Delete \n");
     printf("[3] Insert \n");
     printf("[4] Exit\n \n");
     printf ("\n");
     printf("Enter number of your choice:");
     scanf("%d",&choice);
    } while (choice <1 || choice>4);
	    switch(choice)
		  {
		   case 1:
			  Find();
			  break;
		   case 2:
			  Erase();
			  break;
		   case 3:
			  Insert();
			  break;
		  }
  } while (choice != 4);
}

I hope I got your ideas right - well, I'm open to learn new things. Just tell me if I overlooked something.

Thanks.

Respectfully yours,
the_newbug