Help with printf, gets

That still just loops the "Insert sentence" text.

I got it to work this way but its not what I want:

while(1){

char msg[60];
char ch;
int i=0;

printf("Type a sentence and press ENTER\n");

while ((ch=getchar()) != '\n')
        msg[i++]=ch;

msg[i]='\0';

i=0;
while(msg[i] != '\0')
        putchar(msg[i++]);
printf("\n");
}

Can someone help a novice translate this into gets and puts form? I want to be able to manipulate strings later.

That still just loops the "Insert sentence" text.

I got it to work this way but its not what I want:

while(1){

char msg[60];
char ch;
int i=0;

printf("Type a sentence and press ENTER\n");

while ((ch=getchar()) != '\n')
        msg[i++]=ch;

msg[i]='\0';

i=0;
while(msg[i] != '\0')
        putchar(msg[i++]);
printf("\n");
}

Can someone help a novice translate this into gets and puts form? I want to be able to manipulate strings later.

A novice should not use gets(). And neither should anyone else. It is the #1 buffer overflow function call known to man.

You would normally use fgets() instead, since it takes a buffer size as parameter.

Unfortunately fgets is not available in the standard C51 library. See below:

"The ANSI C Standard Library includes a vast number of routines, most of which are included in the Cx51 Library. Many, however, are not applicable to an embedded application and are excluded from the Cx51 Library."
http://www.keil.com/support/man/docs/c51/c51_xa_librarydif.htm

So it seems I must use gets()

No. What isn't available can be created.

But I took a look at the manual. The gets() in the Keil RTL is not the gets() from the C language standard since it does take a buffer size parameter. That makes it safe to use.

If it hadn't, it would have been trivial two write a new function that had picked up characters one at a time, while keeping track of the buffer space.

Nifty. On the man page for gets the example code is practically the inverse of what I need.

void tst_gets (void) {
  char buf [21];

  do {
    gets (buf, sizeof(buf)-1);
    printf ("Input string \"%s\"", buf);
  } while (buf [0] != '\0');
}

So I try

while(1){

char msg[60];

printf("Type a sentence and press ENTER\n");

while (msg [0] != '\0')
{gets (msg, sizeof(msg)-1);

//puts(msg);
printf("%s\n",msg);
}
}

Which again just loops the "type a sentence" text. Frustrating.

Where is msg[0] set to '\0'?

Jon

Not sure what you mean. I'm pretty new at programming.

I understand gets() will read a line and put a terminating \0 into the string array. Maybe I'm in over my head. I've been trying to get this to work all week.

Try this.

while(1)
  {
  char msg[60];

  printf("Type a sentence and press ENTER\n");
  gets (msg, sizeof(msg)-1);
  printf("%s\n",msg);
  }

Jon

Ah, I was close. Thank you.