putwc(3) Library Functions Manual putwc(3)
NAME
putwc, putwchar, fputwc - Write a wide character to a stream
LIBRARY
Standard C Library (libc)
SYNOPSIS
#include <stdio.h> #include <wchar.h>
wint_t putwc(
wint_t wc,
FILE *stream);
wint_t fputwc(
wint_t wc,
FILE *stream); #include <wchar.h>
wint_t putwchar(
wchar_t wc );
STANDARDS
Interfaces documented on this reference page conform to industry standards as follows:
fputwc(), putwc(), putwchar(): XSH5.0
Refer to the standards(5) reference page for more information about industry standards and associated tags.
PARAMETERS
Specifies the wide character to be converted and written. Points to the output data.
DESCRIPTION
The fputwc() function converts the wchar_t specified by the wc parameter to its equivalent multibyte character and then writes the multi-
byte character to the file or terminal associated with the stream parameter. The function also advances the file position indicator for
stream if the associated file supports positioning requests. If the file does not support positioning requests or was opened in append
mode, the function appends the character to the end of stream. The st_ctime and st_mtime fields of the FILE structure are marked for
update between a successful execution of fputwc() and completion of one of the following: A successfully executed call to fflush() or
fclose() on the same stream A call to exit() or abort()
If an error occurs while the character is being written, the shift state of the output file is undefined. See the RESTRICTIONS section for
information about support for shift-state encoding.
The putwc() function performs the same operation as fputwc(), but can be implemented as a macro on some implementations that conform to
X/Open standards. If implemented as a macro, this function may evaluate stream more than once; therefore, stream should never be imple-
mented as an expression with side effects (for example, as in putwc(wc,*f++)).
The putwchar() macro works like the putwc() function, except that putwchar() writes the character to the standard output stream (stdout).
The call putwchar(wc) is equivalent to putwc(wc, stdout).
[Tru64 UNIX] With the exception of stderr, output streams are, by default, buffered if they refer to files, or line buffered if they refer
to terminals. The standard error output stream, stderr, is unbuffered by default, but using the freopen() function causes it to become
buffered or line buffered. Use the setbuf() function to change the stream's buffering strategy.
RESTRICTIONS
Currently, the operating system does not include locales whose codesets use shift-state encoding. Some sections of this reference page
refer to function behavior with respect to shift sequences. This information is included only for your convenience in developing portable
applications that run on multiple platforms, some of which may supply locales whose codesets do use shift-state encoding.
RETURN VALUES
On successful completion, these functions return the value written. If these functions fail, they return the constant WEOF, set the error
indicator for the stream, and set errno to indicate the error.
ERRORS
If any of the following conditions occur, the putwc(), fputwc(), and putwchar() functions set errno to the corresponding value: The O_NON-
BLOCK flag is set for the file descriptor underlying stream and the process would be delayed in the write operation. The file descriptor
underlying stream is not a valid file descriptor open for writing. An attempt was made to write to a file that exceeds the process's file
size limit or the maximum file size.
The file is a regular file and an attempt was made to write at or beyond the offset maximum associated with the corresponding
stream. The write operation was interrupted by a signal that was caught, and no data was transferred. The wide-character code
specified by the wc parameter does not correspond to a valid character in the current locale. One of the following errors occurred:
The process is a member of a background process group attempting to write to its controlling terminal; TOSTOP is set; the process is
neither ignoring nor blocking SIGTTOU; and the process group of the process is orphaned. A physical I/O error occurred. This condi-
tion is defined in Issue 4 Version 2 and later revisions of the XSH specification. There was no free space remaining on the device
containing the file. An attempt was made to write to a pipe or FIFO that is not open for reading by any process. A SIGPIPE signal
will also be sent to the process.
RELATED INFORMATION
Functions: getc(3), getwc(3), printf(3), putc(3), puts(3), wctomb(3), wprintf(3)
Others: i18n_intro(5), l10n_intro(5), standards(5) delim off
putwc(3)