The Open Group Base Specifications Issue 8
IEEE Std 1003.1-2024
Copyright © 2001-2024 The IEEE and The Open Group

NAME

puts — put a string on standard output

SYNOPSIS

#include <stdio.h>

int puts(const char *
s);

DESCRIPTION

[CX] [Option Start] 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.1-2024 defers to the ISO C standard. [Option End]

The puts() function shall write the string pointed to by s, followed by a <newline>, to the standard output stream stdout. The terminating null byte shall not be written.

[CX] [Option Start] The last data modification and last file status change timestamps of the file shall be marked for update between the successful execution of puts() and the next successful completion of a call to fflush() or fclose() on the same stream or a call to exit() or abort(). [Option End]

RETURN VALUE

Upon successful completion, puts() shall return a non-negative number. Otherwise, it shall return EOF, shall set an error indicator for the stream, [CX] [Option Start]  and errno shall be set to indicate the error. [Option End]

ERRORS

Refer to fputc .


The following sections are informative.

EXAMPLES

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 puts(). 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 ");
puts(asctime(localtime(&now)));
printf("There are %d minutes to the event.\n",
    minutes_to_event);
...

APPLICATION USAGE

The puts() function appends a <newline>, while fputs() does not.

This volume of POSIX.1-2024 requires that successful completion simply return a non-negative integer. There are at least three known different implementation conventions for this requirement:

RATIONALE

None.

FUTURE DIRECTIONS

None.

SEE ALSO

2.5 Standard I/O Streams , fopen , fputs , putc

XBD <stdio.h>

CHANGE HISTORY

First released in Issue 1. Derived from Issue 1 of the SVID.

Issue 6

Extensions beyond the ISO C standard are marked.

Issue 7

Changes are made related to support for finegrained timestamps.

POSIX.1-2008, Technical Corrigendum 1, XSH/TC1-2008/0476 [174,412] and XSH/TC1-2008/0477 [14] are applied.

End of informative text.

 

return to top of page

UNIX® is a registered Trademark of The Open Group.
POSIX™ is a Trademark of The IEEE.
Copyright © 2001-2024 The IEEE and The Open Group, All Rights Reserved
[ Main Index | XBD | XSH | XCU | XRAT ]