cipher program need alil help

hey, i need this encrypt function to accept more than one word as input spaces and punctuation. When i enter more than one word it skips to the end of the program. Any idea

Code:

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#include <stdio.h> 
#include <string.h>
 
// Declare the function
char ShiftCharacter(char unencrypt,int shift_value,int offset);
 
 
int main(int argc, char* argv[])
{
 
        char buff[1024]; 
        int shift_value; 
        int encrypt_text_length;
        int i;
 
        // Say hello 
        puts("**initializing.....**\n\n**linking..........**\n\n"); 
        puts("Welcome agent Brown\n\n"); 
        puts("You have accessed the Caesar Cipher program\n\n"); 
        puts("Please enter the text you wish to encrypt: ");
 
        // Get input from the user
        // It is possible that the user may exceed our allocated space.
        // We could address that but it would cloud the issue. TODO: for later
        scanf("%s",&buff); 
 
        puts("\nEnter your encryption shift value (anything from +-1 to 25): "); 
        scanf("%d",&shift_value); 
 
        // We now have a string and a shift value
        // TODO: Check for empty string and out of range value
 
 
        // Determine how long the string is
        encrypt_text_length = strlen(buff);
 
        // Encrypted the text
        for(i = 0; i < encrypt_text_length; i++)
        {
                buff[ i] = ShiftCharacter(buff[ i],shift_value,i);
        } 
 
        // Display the encrypted text for the user
        printf("\nYour encrypted text is: %s\n",buff); 
 
 
        return 0; /* indicate successful completeion */ 
}
 
 
// This function will shift the character by the determined amount
// For our purpose we are only concerned with the letters a - z
char ShiftCharacter(char unencrypt,int shift_value,int offset)
{

int alphanumber; // The character as a number ( A = 1, B = 2, Z = 26 etc.)
char encrypted_char = unencrypt;
 
// Capital A - Z
if(unencrypt >= 'A' && unencrypt <= 'Z')
{
        alphanumber = unencrypt - 'A';
        alphanumber += shift_value + offset;
        alphanumber = (alphanumber % 26);
        encrypted_char  = (char)(alphanumber + 'A');
 
}
 
// Lowercase a - z
else if(unencrypt >= 'a' && unencrypt <= 'z')
{
        alphanumber = unencrypt - 'a';
        alphanumber += shift_value + offset;
        alphanumber = (alphanumber % 26);
        encrypted_char  = (char)(alphanumber + 'a');
}
 
return encrypted_char;
 
}

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Code:

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        scanf("%s",&buff);

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Getting input this way will stop at the first whitespace character. Try using fgets() instead.

Code:

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// Capital A - Z
if(unencrypt >= 'A' && unencrypt <= 'Z')
{

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Try isupper(), in <ctype.h>. There's an islower() as well.

haha yeah i fixed it. Ive been trying to reset the shift value for every word entered. This is what i have so far but it isnt working.

Code:

---


 

#include <stdio.h> 
#include <string.h>
 
// Declare the function
char ShiftCharacter(char unencrypt,int shift_value,int offset);
 
 
int main(int argc, char* argv[])
{
 
        char buff[1024]; 
        int shift_value; 
        int encrypt_text_length;
        int i;
        int x;
        int y = 0;
 
        // Say hello 
        puts("**initializing.....**\n\n**linking..........**\n\n"); 
        puts("Welcome agent Brown\n\n"); 
        puts("You have accessed the Caesar Cipher program\n\n"); 
        puts("Please enter the text you wish to encrypt: ");
 
        // Get input from the user
        // It is possible that the user may exceed our allocated space.
        // We could address that but it would cloud the issue. TODO: for later
        fgets(buff, sizeof buff, stdin); 
 
        puts("\nEnter your encryption shift value (anything from +-1 to 25): "); 
        scanf("%d",&shift_value); 
 
        // We now have a string and a shift value
        // TODO: Check for empty string and out of range value
 
 
        // Determine how long the string is
        encrypt_text_length = strlen(buff);
 
        // Encrypted the text
        for(i = 0; i < encrypt_text_length; i++)
        {
                buff[ i] = ShiftCharacter(buff[ i],shift_value,i);
        }

 
// Encrypted the text 
        for(x = 0; x < encrypt_text_length; x++) 
        { 
    // if the current character is a space reset the offset to zero
    // otherwise add one to the offset
    if(buff[i] == ' ')
    {
          y = 0;
    }
    else
    {
          y++;
    }
 
    buff[i] = ShiftCharacter(buff[i],shift_value,i); 
        }

 
        // Display the encrypted text for the user
        printf("\nYour encrypted text is: %s\n",buff); 
 
 
        return 0; /* indicate successful completeion */ 
}
 
 
// This function will shift the character by the determined amount
// For our purpose we are only concerned with the letters a - z
char ShiftCharacter(char unencrypt,int shift_value,int offset)
{

int alphanumber; // The character as a number ( A = 1, B = 2, Z = 26 etc.)
char encrypted_char = unencrypt;
 
// Capital A - Z
if(unencrypt >= 'A' && unencrypt <= 'Z')
{
        alphanumber = unencrypt - 'A';
        alphanumber += shift_value + offset;
        alphanumber = (alphanumber % 26);
        encrypted_char  = (char)(alphanumber + 'A');
 
}
 
// Lowercase a - z
else if(unencrypt >= 'a' && unencrypt <= 'z')
{
        alphanumber = unencrypt - 'a';
        alphanumber += shift_value + offset;
        alphanumber = (alphanumber % 26);
        encrypted_char  = (char)(alphanumber + 'a');
}
 
return encrypted_char;
 
}

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