Inputting a sentence into a variable

**kopite** · 12-01-2003

Right I need to be able to input a sentence into a c program that can be stored and then later sent over to another program using sockets.

The problem I`m having at the mom is readin in the sentence.

I`ve tried setting up a string but when I read into it only the last word is stored.

Whats the best way to do this ?

cheers

**velius** · 12-01-2003

Show what you are doing. If your reading from stdin you could use getline(). If you doing it all inside the program you may need the string library functions.

**quzah** · 12-01-2003

Well you could always read the FAQ.

Quzah.

**kopite** · 12-01-2003

Trying to Make an sms program using sockets.

At the moment I am usign scanf but it didnt work.

I ahve to be able read in a string of less than 160 characters./

**WaltP** · 12-01-2003

fgets()

**kopite** · 12-01-2003

so the code would be

Code:

fgets("%C", stringname);

?

**velius** · 12-01-2003

No.

Code:

fgets(char* buffer, int length, FILE* file);

Which is used like this...

Code:

char buff[256];

fgets(buff, sizeof(buff), stdin); /* read from stdin */

**kopite** · 12-02-2003

I want to be able to read the input from the keyboard but fgets is to read from a file isnt it?

**velius** · 12-02-2003

If you read the comment after the fgets() you would see that the use of stdin is used to read from standard input which is the keyboard.

**kopite** · 12-02-2003

Heres the code I have so far

Code:

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <errno.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <netdb.h>
main()
{
int x=1;
int selection;
char username[10];
char buf[160];
char *p;
printf("Please Enter you Username \n");
scanf("%s", username);
printf("your username is %s \n", username);
while(x!=0)
   {
   printf("please choose an option from the following menu:\n\n");
   printf("1. Send a message\n");
   printf("2. Check userlist\n");
   printf("3. Log off Program\n");
   scanf("%d", &selection);
   switch(selection)
      {
      case 1 : printf("whats the message?\n");
               if (fgets(buf, sizeof(buf), stdin) !=NULL)
	          {
	           printf("the message is as follows : %s\n", buf);
		   if ((p = strchr(buf, '\n')) != NULL)
                   *p = '\0';
                   printf ("And now it's >%s<\n", buf);
		   }
	       break;
      case 2 : printf("the userlist is as follows \n");
               break;
      case 3 : printf("now logging you off \n");
               x=0;
	       break;
      }



   }

}

The thing is the fgets wont allow me to enter anything. I have tried it without the if loop and with it but neither works.

any ideas?

**quzah** · 12-02-2003

Don't mix scanf and fgets. scanf leaves newline characters in the input stream. fgets reads until a newline, which since there is one already in the stream, concludes its work.

Also, if you had actually read the link I gave you in my first reply, your second and third posts wouldn't have been necessary.

But hey, why bother reading when people are trying to help, right?

Quzah.

**kopite** · 12-02-2003

chill out man.

I read the link you posted but I coudlnt get my head around it. At the moment I am totally stressed out and all rational though has gone out the window.

so if I remove all the scanf`s and replace them with fgets it should work?

Thanks for any help.

**velius** · 12-02-2003

I don't see anything wrong with the code you have written.

**kopite** · 12-02-2003

Ive changed the first scanf to fgets so now the username is read ina nd taht works. THe problem now is to read in the integer for the menu. When I compile using gcc I get

Code:

warning: passing arg 1 of `fgets' makes pointer from integer without a cast

I`m not sure what to make of this now

the code I`m using for it is as follows

Code:

 fgets(selection, 1, stdin);

**quzah** · 12-02-2003

Originally posted by velius
I don't see anything wrong with the code you have written.

It is valid code, it just doesn't do what he expects it to. As I've stated, his problem is that he's mixing scanf with fgets. Again as stated, scanf leaves the newline caracter in the input stream. Then, he calls fgets, which reads until it reaches the size limit, or a newline. Since there is a newline there already, it doesn't read anything except for the newline.

Let me illustrate clearer

Code:

"please choose an option from the following menu:"

"1. Send a message"
"2. Check userlist"
"3. Log off Program"

At which points, it sits waiting for you to type...

Code:

1enter

Scanf strips out the 1, leaving the newline.

Code:

fgets( ... )

Since there is a newline already in the buffer, it terminates the fgets call, because that is what fgets is supposed to do. It reads until it reaches the newline. There is one there, so it does its job and only reads that.

Quzah.

Thread: Inputting a sentence into a variable

Thread Tools

Search Thread

Display

Inputting a sentence into a variable

Similar Threads

static class variable vs. global variable

return values from function with variable number of arguments

variable being reset

About classes and HINSTANCE variable to Main

creating class, and linking files