typical error problem

[stormy]

Hi guys, I really have been trying to fix this one myself but I am just learning C so I my skill limits me, naturally.

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>

#define BUFFER 20

int i;
int iPort;
void display_usage(void);
char *target_ip,the_buffer[BUFFER],return_data[BUFFER];
char input_Command[BUFFER];
char jumble_data(char temp_data);

int main( int argc, char *argv[] ) {

	 if( argc < 2 )
         {
         display_usage();
         exit(1);
         }
        
	 target_ip = argv[1]; // TARGETIP had to be a pointer
	 iPort = atoi(argv[2]);

	 // Prompt user for command
	 printf("command>");

         if ( fgets(input_Command, sizeof input_Command, stdin) )
         {
         char *newline = strchr(input_Command, '\n');
                if ( newline )
                {
                *newline = '\0'; /* strip trailing \n */
                }
         }

	 // send input to jumble_data
	 *input_Command = jumble_data(input_Command);
      
      	 //setup sockets
         int testsocket;        
         struct sockaddr_in thetarget;  
         testsocket = socket(AF_INET, SOCK_STREAM, 0);  

         thetarget.sin_family = AF_INET; //always AF_INET        
         thetarget.sin_port = htons(iPort);         
         thetarget.sin_addr.s_addr = inet_addr(target_ip); // TARGETIP is argv[1]
	
         connect(testsocket, (struct sockaddr *)&thetarget, sizeof(struct sockaddr)); // make the connection
	 send(testsocket, input_Command, strlen(input_Command), 0);  // send the data
         
	 /*while (1) {
	 recv(testsocket, return_data, strlen(the_buffer), 0); 	
	 printf("%s\n", return_data); 
	 }*/

	 perror("connect"); 
	 return(0);
}

void display_usage(void)
{
       fprintf(stderr, "Usage: ./connect 127.0.0.1 9999\n" );
}

/* Fucntion Summary:
Take in user supplied command and inserts 4 random characters inbetween each character of the origianl command 
*/

char jumble_data(char temp_Data) /* take in input_Command and put it in temp_Data */
{
	int i, k, j;
	char jumbled_data[sizeof temp_Data * 4]; /* multiply temp_Data's array size by 4 to hold random chars */	

        for ( i = 0, k = 0; temp_Data[i] != '\0'; ++i ) /* until temp_data[i] reaches newline char, increment and loop */
        {
        jumbled_data[k++] = temp_Data[i]; /* assign temp_Data[i] to jumbled_Data[k] then increment (jumbled_Data[k++]) */

	/* At this point if the user submitted command would have been "destroy", jumbled_Data[0] would contain the "d" and jumbled_D
	ta[k] == jumbled_Data[1]. */
                
		for ( j = 0; j < 4; ++j ) /* until j == 4, increment */
                {
                jumbled_data[k++] = rand() % 26 + 'a'; /* fill next 4 char cells with a random character */ 
                }
		/* Now restart the loop */
        }
return(jumbled_data[BUFFER]);
}

Please ignore my horrible style.

[nonpuz]

Most people arnt even going to bother reading your code without you asking a question.

[stormy]

Oh, yes, my fault. It was 3 am when I made this post I kind of shut down. Here are the errors I'm getting:

ob.c: In function `main':
ob.c:41: warning: passing arg 1 of `jumble_data' makes integer from pointer without a cast
ob.c: In function `jumble_data':
ob.c:78: error: subscripted value is neither array nor pointer
ob.c:80: error: subscripted value is neither array nor pointer

Line 41 is:

*input_Command = jumble_data(input_Command);

I think it may have something to do with my jumble_data function being broke.

[spydoor]

input_Command is a char array.
your prototype and definition for jumble_data is for a single char

maybe change to

char jumble_data(char *temp_data);

[filker0]

Once you make it so that you're passing a char * to jumble_data() (you can write this as "char temp_data[]", btw), you'll also have to change the use of sizeof, as "sizeof(temp_data)" will return the size of a pointer to char, and "sizeof(*temp_data)" will return the size of a char, which is 1. If you're looking for the size of the array passed to jumble_data(), you'll have to do it differently. If you always pass input_Command to this function, you could simply say "sizeof(input_Command) * 4", as the compiler knows the size from your declaration. Alternatively, you may be able to get away with using a declaration like

char jumble_data(char temp_data[BUFFER])

if the input array is always BUFFER chars, and then sizeof(temp_data) will return BUFFER * sizeof(char), as you expect.

Your function jumble_data() returns a char. It is always the character at jumbled_data[20]. You are storing this single character at the beginning of the array input_Command. I doubt that this is what you intend.

I suggest that you explore C arrays and pointers further, especially as they relate to strings in C.

[dwks]

And:

         if ( fgets(input_Command, sizeof input_Command, stdin) )
         {
         char *newline = strchr(input_Command, '\n');
                if ( newline )
                {
                *newline = '\0'; /* strip trailing \n */
                }
         }

You should probably have an else in there to handle the case of fgets() failing.