This manual page is part of the POSIX Programmer's Manual. The Linux implementation of this interface

       Reading a line that overflows the array pointed to by s results in undefined behavior. The use of fgets()
       is recommended.

       Since the user cannot specify the length of the  buffer  passed  to  gets(),  use  of  this  function  is
       discouraged. The length of the string read is unlimited. It is possible to overflow this buffer in such a
       way as to cause applications to fail, or possible system security violations.

       Applications should use the fgets() function instead of the obsolescent gets() function.

       Portions of this text are reprinted and reproduced in electronic form from IEEE Std 1003.1-2017, Standard
       for  Information  Technology  --  Portable  Operating  System  Interface  (POSIX),  The  Open  Group Base
       Specifications Issue 7, 2018 Edition, Copyright (C) 2018 by the Institute of Electrical  and  Electronics
       Engineers, Inc and The Open Group.  In the event of any discrepancy between this version and the original
       IEEE  and The Open Group Standard, the original IEEE and The Open Group Standard is the referee document.
       The original Standard can be obtained online at http://www.opengroup.org/unix/online.html .

       Any typographical or formatting errors that appear in this page are most likely to have  been  introduced
       during   the   conversion  of  the  source  files  to  man  page  format.  To  report  such  errors,  see
       https://www.kernel.org/doc/man-pages/reporting_bugs.html .

IEEE/The Open Group                                   2017                                          GETS(3POSIX)

       The  functionality  described  on  this  reference  page is aligned with the ISO C standard. Any conflict
       between the requirements described  here  and  the  ISO C  standard  is  unintentional.  This  volume  of
       POSIX.1‐2017 defers to the ISO C standard.

       The  gets() function shall read bytes from the standard input stream, stdin, into the array pointed to by
       s, until a <newline> is read or an end-of-file condition is encountered. Any <newline> shall be discarded
       and a null byte shall be placed immediately after the last byte read into the array.

       The gets() function may mark the last data access timestamp  of  the  file  associated  with  stream  for
       update.  The  last  data access timestamp shall be marked for update by the first successful execution of
       fgetc(), fgets(), fread(), fscanf(), getc(), getchar(), getdelim(), getline(), gets(), or  scanf()  using
       stream that returns data not supplied by a prior call to ungetc().

       Refer to fgetc().

       Thefollowingsectionsareinformative.

       None.

       The gets() function may be removed in a future version.

       gets — get a string from a stdin stream

       This  manual  page  is part of the POSIX Programmer's Manual.  The Linux implementation of this interface
       may differ (consult the corresponding Linux manual page for details of Linux behavior), or the  interface
       may not be implemented on Linux.

       The standard developers decided to mark the gets() function as obsolescent even though it is in the ISO C
       standard due to the possibility of buffer overflow.

       Upon  successful  completion, gets() shall return s.  If the end-of-file indicator for the stream is set,
       or if the stream is at end-of-file, the end-of-file indicator for the stream  shall  be  set  and  gets()
       shall  return  a  null  pointer. If a read error occurs, the error indicator for the stream shall be set,
       gets() shall return a null pointer, and set errno to indicate the error.

Section2.5, StandardI/OStreams, feof(), ferror(), fgets()

       The Base Definitions volume of POSIX.1‐2017, <stdio.h>

       #include <stdio.h>

       char *gets(char *s);