Why GCC does warn me when I using gets() function for accessing file?

[cuthbert]

After compiling the source code with gcc v.4.1.1, I got a warning message:
"/tmp/ccixzSIL.o: In function 'main';ex.c: (.text+0x9a): warning: the 'gets' function is dangerous and should not be used."

Could anybody tell me why gets() function is dangerous??
Thank you very much.

Cuthbert

Here is the source code I was testing:

---------------------------------------------------
* count.c -- using standard I/O */

#include "stdafx.h"
#include <stdio.h>
#include <stdlib.h> // ANSI C exit() prototype

int main(int argc, char *argv[])
{
    int ch;         // place to store each character as read
    FILE *fp;       // "file pointer" 
    long count = 0;

    if (argc != 2)
    {
        printf("Usage: %s filename\n", argv[0]);
        exit(1);
    }
    if ((fp = fopen(argv[1], "r")) == NULL)
    {
        printf("Can't open %s\n", argv[1]);
        exit(1);
    }
    while ((ch = getc(fp)) != EOF)
    {
       putc(ch,stdout);  // same as putchar(ch);
       count++;
    }
    fclose(fp);
    printf("File %s has %ld characters\n", argv[1], count);
    
    return 0;
}
------------------------------------------------------------------

[ZuK]

Could anybody tell me why gets() function is dangerous??

With simple words. No matter how large you make the buffer, the user just has to input one character more and boooom.
Kurt

[ssharish2005]

Read FAQ for a proper reason
Why gets() is wrong


ssharish2005

[dwks]

And what to use instead, fgets(): http://faq.cprogramming.com/cgi-bin/...&id=1043284385

[quzah]

Of course it could be warning you because you don't actually use it for files too.


Quzah.

[sangken]

Perhaps i've gone blind but i cant see any gets() calls in the code you just posted cuthbert

[jafet]

...maybe Ken took it off too? Bad programming habits should be removed at any cost

[itsme86]

Failure to do even one simple google search for the answer always astounds me: http://www.google.com/search?hl=en&l...tion+dangerous