The Open Group Base Specifications Issue 6
IEEE Std 1003.1, 2004 Edition
Copyright © 2001-2004 The IEEE and The Open Group, All Rights reserved.
A newer edition of this document exists here


gets - get a string from a stdin stream


#include <stdio.h>

char *gets(char *


[CX] [Option Start] 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 IEEE Std 1003.1-2001 defers to the ISO C standard. [Option End]

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.

[CX] [Option Start] The gets() function may mark the st_atime field of the file associated with stream for update. The st_atime field shall be marked for update by the first successful execution of fgetc(), fgets(), fread(), getc(), getchar(), gets(), fscanf(), or scanf() using stream that returns data not supplied by a prior call to ungetc(). [Option End]


Upon successful completion, gets() shall return s. 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, [CX] [Option Start]  and set errno to indicate the error. [Option End]


Refer to fgetc().

The following sections are informative.




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.

It is recommended that the fgets() function should be used to read input lines.






feof(), ferror(), fgets(), the Base Definitions volume of IEEE Std 1003.1-2001, <stdio.h>


First released in Issue 1. Derived from Issue 1 of the SVID.

Issue 6

Extensions beyond the ISO C standard are marked.

End of informative text.

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