Movatterモバイル変換

fputs(3p) — Linux manual page

FPUTS(3P)               POSIX Programmer's ManualFPUTS(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 *restricts, FILE *restrictstream);

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.1‐2017 defers to the ISO C standard.       Thefputs() function shall write the null-terminated string       pointed to bys to the stream pointed to bystream.  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 offputs() and the next successful completion of a call       tofflush() orfclose() on the same stream or a call toexit() orabort().

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 seterrno to indicate the error.

ERRORS        top

       Refer tofputc(3p).The following sections are informative.

EXAMPLES        top

Printing to Standard Output       The following example gets the current time, converts it to a       string usinglocaltime() andasctime(), and prints it to standard       output usingfputs().  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);           ...

APPLICATION USAGE        top

       Theputs() function appends a <newline> whilefputs() does not.       This volume of POSIX.1‐2017 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

       Thefputs() function is one whose source code was specified in the       referencedThe 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 offerror(); however, for compatibility with       extant implementations, several implementations would, upon       success, return a positive value representing the last byte       written.

FUTURE DIRECTIONS        top

       None.

SEE ALSO        top

Section 2.5,Standard I/O Streams,fopen(3p),putc(3p),puts(3p)       The Base Definitions volume of POSIX.1‐2017,stdio.h(0p)

COPYRIGHT        top

       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 athttp://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, seehttps://www.kernel.org/doc/man-pages/reporting_bugs.html .IEEE/The Open Group                2017FPUTS(3P)

Pages that refer to this page:stdio.h(0p), puts(3p)

HTML rendering created 2025-09-06 byMichael Kerrisk, author ofThe Linux Programming Interface. For details of in-depthLinux/UNIX system programming training courses that I teach, lookhere. Hosting byjambit GmbH.