1GETS(3P)                   POSIX Programmer's Manual                  GETS(3P)
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PROLOG

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

12       gets — get a string from a stdin stream
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SYNOPSIS

15       #include <stdio.h>
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17       char *gets(char *s);
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DESCRIPTION

20       The functionality described on this reference page is aligned with  the
21       ISO C  standard.  Any  conflict between the requirements described here
22       and the ISO C standard is unintentional. This  volume  of  POSIX.1‐2017
23       defers to the ISO C standard.
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25       The  gets()  function  shall read bytes from the standard input stream,
26       stdin, into the array pointed to by s, until a <newline> is read or  an
27       end-of-file  condition is encountered. Any <newline> shall be discarded
28       and a null byte shall be placed immediately after the  last  byte  read
29       into the array.
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31       The gets() function may mark the last data access timestamp of the file
32       associated with stream for update. The last data access timestamp shall
33       be  marked  for  update  by  the first successful execution of fgetc(),
34       fgets(), fread(), fscanf(), getc(), getchar(),  getdelim(),  getline(),
35       gets(),  or  scanf()  using  stream that returns data not supplied by a
36       prior call to ungetc().
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RETURN VALUE

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

47       Refer to fgetc().
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49       The following sections are informative.
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EXAMPLES

52       None.
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APPLICATION USAGE

55       Reading  a  line  that  overflows  the array pointed to by s results in
56       undefined behavior. The use of fgets() is recommended.
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58       Since the user cannot specify  the  length  of  the  buffer  passed  to
59       gets(),  use  of this function is discouraged. The length of the string
60       read is unlimited. It is possible to overflow this buffer in such a way
61       as  to  cause  applications to fail, or possible system security viola‐
62       tions.
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64       Applications should use the fgets() function instead of the obsolescent
65       gets() function.
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RATIONALE

68       The standard developers decided to mark the gets() function as obsoles‐
69       cent even though it is in the ISO C standard due to the possibility  of
70       buffer overflow.
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FUTURE DIRECTIONS

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

76       Section 2.5, Standard I/O Streams, feof(), ferror(), fgets()
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78       The Base Definitions volume of POSIX.1‐2017, <stdio.h>
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81       Portions  of  this text are reprinted and reproduced in electronic form
82       from IEEE Std 1003.1-2017, Standard for Information Technology --  Por‐
83       table  Operating System Interface (POSIX), The Open Group Base Specifi‐
84       cations Issue 7, 2018 Edition, Copyright (C) 2018 by the  Institute  of
85       Electrical  and  Electronics Engineers, Inc and The Open Group.  In the
86       event of any discrepancy between this version and the original IEEE and
87       The  Open Group Standard, the original IEEE and The Open Group Standard
88       is the referee document. The original Standard can be  obtained  online
89       at http://www.opengroup.org/unix/online.html .
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91       Any  typographical  or  formatting  errors that appear in this page are
92       most likely to have been introduced during the conversion of the source
93       files  to  man page format. To report such errors, see https://www.ker
94       nel.org/doc/man-pages/reporting_bugs.html .
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98IEEE/The Open Group                  2017                             GETS(3P)
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