trouble joining strings

[readi83]

Hi, I am having trouble joining strings together and wonder if anyone can help. At the moment my strings are joining as string1 string2 string3 (ie with spaces between) and i want them to join as string1string2string3. Also when I output the final string before the 1's and 0's are printed I get a few random characters----is there a way to get rid of these? Many thanks for all suggestions

//Convert whole string to binary
  for (i=0; i<messages; i++)
  {
  dec2bin(e_array[i], t_array_bin);
  printf("\nBinary message of %d is %s\n", e_array[i], t_array_bin); 
  strcat(e_array_bin, t_array_bin);
  }
  printf("\nThe binary message is %s", e_array_bin);
  getchar();
  store_message(e_array_bin);    //put in file

[itsme86]

When half the symbols in the code you present aren't shown to us, it's hard to figure out what exactly is going on. Try posting the whole thing.

[readi83]

ok, heres the whole code, apologies that it is quite messy
(Dec2bin is a function that converts a decimal value into a binary string)
Also, this is schoolwork---its not for production! Any help appreciated

// Function gets the message to be encrypted (from a binary file)

#include <stdio.h>                // Code to get message
#include <math.h>
#include <stdlib.h>
#include <string.h>

FILE *pfile = NULL;      //declare a file pointer for file input/output

void getmsg (void)
{
   char nbin[100];      //binary conversion of n
   char e_array_bin[500];  //binary store encrypted message
   char t_array_bin[500];  //temp binary store encrypted message
   char extra[50]="0";
 
   int msglength=0; // variable to store the length of the message
   int nlength=0; // variable to store the length of nbin
   int encryptlength=0;
   int blocklength=0;
   int messages=0;
   int emsg;
  char msg[500];

   int m_array[50]; //array to store blocks
   int e_array[500];
   char txt_array[500];

   int n=0;
   int m=1;
   int i=0;
   int j=0;
   int count=0;
   int start=0;
   int sum=0;
   int x=0;
   int num=0;

   char *filename4 = "\message.txt"; 

   //Get the message from the 'message' file
   pfile = fopen(filename4, "r");

	if (pfile == NULL)
		{
		printf("Erorr creating file %s for reading. Terminating....", filename4);
   		getchar();
		}

	fscanf(pfile, "%s", &msg);
	printf("\nValue retrieved: %s\n",msg);
   fclose(pfile);
   getchar();

   // gets the length of the message in bits
   msglength=strlen(msg)-1;
   printf("The length of the message is %d\n\n", msglength);
   getchar();

   n=get_n();  //get n from public key
   // Convert the value of n into a binary string
   dec2bin(n,nbin);

   // gets the length of n in bits
   nlength=strlen(nbin)-1;
   printf("The length of the n is %d bits\n\n", nlength);
   getchar();

   //gets the length of n-1 in bits
   encryptlength=nlength-1;
   printf("The no. of bits to be encrypted per time is %d", encryptlength);
   getchar();

   //Pad the zeros out when the message does not split up evenly
   while ((msglength/encryptlength)%2 != 0)
   {
   strcat(msg, extra);  // Adds a '0' to the end of the message
   msglength++;
   }
   printf("Message is now %s\n", msg);

   // Get the number of individual messages to be encrypted
   messages=msglength/encryptlength;
   printf("Messages to encrypt is %d", messages);
   getchar();

   count=encryptlength;    //count set to no of bits we need to sum for each block
   printf("The value of count is %d", count);
   getchar();

   x=encryptlength-1;
   for (i=0; i<messages; i++)
   {
    	for (j=start; j<count; j++)
      {
         if (msg[j] == '1')
         {
         num = pow(2,x);// Multiply by power of 2 relevant
         sum=sum+num;     //sum will be in decimal
         //printf("Sum = %d\n", sum);
         }
         x--;
      }
      printf("The message:%d is %d\n", m, sum );
      m++;
      m_array[i]=sum;
      //printf("The value to be put in the array is %d\n", sum);
      sum=0;
      x=encryptlength-1;
      start=count;
      count=count+encryptlength;
      getchar();
  }
  printf("Blocks to encrypt are as follows: ");
  for (i=0; i<messages; i++)
  {
  	printf("%d ", m_array[i]);
  }
  getchar();

  //Display the results of encrypting each block
  sum=0;
  for (i=0; i<messages; i++)
  {
  e_array[i]=encrypt(m_array[i]);
  printf("Encrypted value is: %d\n ", e_array[i]);
  getchar();
  }

  //Display encrypted message
  printf("Encrypted message:");
  for (i=0; i<messages; i++)
  {
  printf("%d", e_array[i]);
  }

//Convert whole encrypted string to binary
  for (i=0; i<messages; i++)
  {
  	dec2bin(e_array[i], t_array_bin);
  	printf("\nBinary message of %d is %s\n", e_array[i], t_array_bin);
  	strcat(e_array_bin, t_array_bin);
  }
  printf("\nThe binary message is %s", e_array_bin);
  getchar();
  store_emessage(e_array_bin);    //put in file  */
}

[quzah]

You could just do it the easy way:

char buf[BUFSIZ] = {0};
char buf1[] = "Hello";
char buf2[] = "World!";

strcat( buf, buf1 );
strcat( buf, " " );
strcat( buf, buf2 );

printf("%s\n", buf );

Quzah.