gets(3) — Linux manual page

gets(3)                 Library Functions Manual                 gets(3)

NAME

       gets - get a string from standard input (DEPRECATED)

LIBRARY

       Standard C library (libc, -lc)

SYNOPSIS

       #include <stdio.h>

       [[deprecated]] char *gets(char *s);

DESCRIPTION

       Never use this function.

       gets() reads a line from stdin into the buffer pointed to by s
       until either a terminating newline or EOF, which it replaces with
       a null byte ('\0').  No check for buffer overrun is performed
       (see BUGS below).

RETURN VALUE

       gets() returns s on success, and NULL on error or when end of
       file occurs while no characters have been read.  However, given
       the lack of buffer overrun checking, there can be no guarantees
       that the function will even return.

ATTRIBUTES

       For an explanation of the terms used in this section, see
       attributes(7).
       ┌─────────────────────────────────────┬───────────────┬─────────┐
       │ Interface                           │ Attribute     │ Value   │
       ├─────────────────────────────────────┼───────────────┼─────────┤
       │ gets()                              │ Thread safety │ MT-Safe │
       └─────────────────────────────────────┴───────────────┴─────────┘

STANDARDS

       POSIX.1-2008.

HISTORY

       C89, POSIX.1-2001.

       LSB deprecates gets().  POSIX.1-2008 marks gets() obsolescent.
       ISO C11 removes the specification of gets() from the C language,
       and since glibc 2.16, glibc header files don't expose the
       function declaration if the _ISOC11_SOURCE feature test macro is
       defined.

BUGS

       Never use gets().  Because it is impossible to tell without
       knowing the data in advance how many characters gets() will read,
       and because gets() will continue to store characters past the end
       of the buffer, it is extremely dangerous to use.  It has been
       used to break computer security.  Use fgets() instead.

       For more information, see CWE-242 (aka "Use of Inherently
       Dangerous Function") at
       http://cwe.mitre.org/data/definitions/242.html

SEE ALSO

       read(2), write(2), ferror(3), fgetc(3), fgets(3), fgetwc(3),
       fgetws(3), fopen(3), fread(3), fseek(3), getline(3), getwchar(3),
       puts(3), scanf(3), ungetwc(3), unlocked_stdio(3),
       feature_test_macros(7)

COLOPHON

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Linux man-pages 6.9.1          2024-06-15                        gets(3)

Pages that refer to this page: fgetc(3), stdio(3), feature_test_macros(7)

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