gets

Section: C Library Functions (3)
Updated: 202-0-08
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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 ([aq][rs]0[aq]). 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	M-Safe

 

STANDARDS

POSIX.-2008.  

HISTORY

C89, POSIX.-2001. LSB deprecates gets(). POSIX.-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 CW-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)

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Index

NAME

LIBRARY

SYNOPSIS

DESCRIPTION

RETURN VALUE

ATTRIBUTES

STANDARDS

HISTORY

BUGS

SEE ALSO