putwc, putwchar, fputwc - Write a wide character to a stream
Standard C Library (libc.so, libc.a)
wchar_t wc );
For the fputwc() and putwc() functions, application developers may want to specify an #include statement for <stdio.h> before the one for <wchar.h> if programs are being developed for multiple platforms. The additional #include statement is not required on Tru64 UNIX systems or by ISO or X/Open standards, but may be required on other vendors' systems that conform to these standards. For the putwchar() function, the XPG4 standard specifies the parameter type wint_t rather than wchar_t, which is required by the current version of the ISO C standard. On Tru64 UNIX systems, both types resolve to int; however, wchar_t and wint_t may not be equivalent types on other systems that conform to these standards.
Interfaces documented on this reference page conform to industry standards as follows:
fputwc(), putwc(), putwchar(): XPG4, XPG4-UNIX
Refer to the standards(5) reference page for more information about industry standards and associated tags.
Specifies the wide character to be converted and written. Points to the output data.
The fputwc() function converts the wchar_t specified by the wc parameter to its equivalent multibyte character and then writes the multibyte 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 implemented 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).
[Digital] 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.
Currently, the Tru64 UNIX product 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.
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.
If any of the following conditions occur, the putwc(), fputwc(), and putwchar() functions set errno to the corresponding value: The O_NONBLOCK 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 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. [XPG4-UNIX] A physical I/O error occurred. 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.
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