fputs(3p) — Linux manual page


FPUTS(3P)                 POSIX Programmer's Manual                FPUTS(3P)

PROLOG         top

       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.

NAME         top

       fputs — put a string on a stream

SYNOPSIS         top

       #include <stdio.h>

       int fputs(const char *restrict s, FILE *restrict stream);

DESCRIPTION         top

       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().

RETURN VALUE         top

       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.

ERRORS         top

       Refer to fputc(3p).

       The following sections are informative.

EXAMPLES         top

   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;
           printf("The time is ");
           fputs(asctime(localtime(&now)), stdout);
           printf("There are still %d minutes to the event.\n",


       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.

RATIONALE         top

       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.



SEE ALSO         top

       Section 2.5, Standard I/O Streams, fopen(3p), putc(3p), puts(3p)

       The Base Definitions volume of POSIX.1‐2008, stdio.h(0p)

COPYRIGHT         top

       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)