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PROLOG | NAME | SYNOPSIS | DESCRIPTION | RETURN VALUE | ERRORS | EXAMPLES | APPLICATION USAGE | RATIONALE | FUTURE DIRECTIONS | SEE ALSO | COPYRIGHT |
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GETS(3P) POSIX Programmer's Manual GETS(3P)
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.
gets — get a string from a stdin stream
#include <stdio.h>
char *gets(char *s);
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().
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.
Refer to fgetc(3p).
The following sections are informative.
None.
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.
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.
The gets() function may be removed in a future version.
Section 2.5, Standard I/O Streams, feof(3p), ferror(3p),
fgets(3p)
The Base Definitions volume of POSIX.1‐2017, stdio.h(0p)
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(3P)
Pages that refer to this page: stdio.h(0p), fgetc(3p), fgets(3p), fread(3p), stdin(3p)
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HTML rendering created 2024-06-26 by Michael Kerrisk, author of The Linux Programming Interface. For details of in-depth Linux/UNIX system programming training courses that I teach, look here. Hosting by jambit GmbH. |
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