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FPUTS(3P) POSIX Programmer's Manual FPUTS(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.
fputs — put a string on a stream
#include <stdio.h>
int fputs(const char *restrict s, FILE *restrict stream);
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.1‐2008 defers to the ISO C standard.
The fputs() function shall write the null-terminated string pointed
to by s to the stream pointed to by stream. The terminating null
byte shall not be written.
The last data modification and last file status change timestamps of
the file shall be marked for update between the successful execution
of fputs() and the next successful completion of a call to fflush()
or fclose() on the same stream or a call to exit() or abort().
Upon successful completion, fputs() shall return a non-negative
number. Otherwise, it shall return EOF, set an error indicator for
the stream, and set errno to indicate the error.
Refer to fputc(3p).
The following sections are informative.
Printing to Standard Output
The following example gets the current time, converts it to a string
using localtime() and asctime(), and prints it to standard output
using fputs(). It then prints the number of minutes to an event for
which it is waiting.
#include <time.h>
#include <stdio.h>
...
time_t now;
int minutes_to_event;
...
time(&now);
printf("The time is ");
fputs(asctime(localtime(&now)), stdout);
printf("There are still %d minutes to the event.\n",
minutes_to_event);
...
The puts() function appends a <newline> while fputs() does not.
This volume of POSIX.1‐2008 requires that successful completion
simply return a non-negative integer. There are at least three known
different implementation conventions for this requirement:
* Return a constant value.
* Return the last character written.
* Return the number of bytes written. Note that this implementation
convention cannot be adhered to for strings longer than {INT_MAX}
bytes as the value would not be representable in the return type
of the function. For backwards-compatibility, implementations can
return the number of bytes for strings of up to {INT_MAX} bytes,
and return {INT_MAX} for all longer strings.
The fputs() function is one whose source code was specified in the
referenced The C Programming Language. In the original edition, the
function had no defined return value, yet many practical
implementations would, as a side-effect, return the value of the last
character written as that was the value remaining in the accumulator
used as a return value. In the second edition of the book, either the
fixed value 0 or EOF would be returned depending upon the return
value of ferror(); however, for compatibility with extant
implementations, several implementations would, upon success, return
a positive value representing the last byte written.
None.
Section 2.5, Standard I/O Streams, fopen(3p), putc(3p), puts(3p)
The Base Definitions volume of POSIX.1‐2008, stdio.h(0p)
Portions of this text are reprinted and reproduced in electronic form
from IEEE Std 1003.1, 2013 Edition, Standard for Information
Technology -- Portable Operating System Interface (POSIX), The Open
Group Base Specifications Issue 7, Copyright (C) 2013 by the
Institute of Electrical and Electronics Engineers, Inc and The Open
Group. (This is POSIX.1-2008 with the 2013 Technical Corrigendum 1
applied.) 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.unix.org/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 2013 FPUTS(3P)
Pages that refer to this page: stdio.h(0p), puts(3p)