| .\" Copyright (c) Bruno Haible <haible@clisp.cons.org> |
| .\" |
| .\" %%%LICENSE_START(GPLv2+_DOC_ONEPARA) |
| .\" This is free documentation; you can redistribute it and/or |
| .\" modify it under the terms of the GNU General Public License as |
| .\" published by the Free Software Foundation; either version 2 of |
| .\" the License, or (at your option) any later version. |
| .\" %%%LICENSE_END |
| .\" |
| .\" References consulted: |
| .\" GNU glibc-2 source code and manual |
| .\" Dinkumware C library reference http://www.dinkumware.com/ |
| .\" OpenGroup's Single UNIX specification http://www.UNIX-systems.org/online.html |
| .\" ISO/IEC 9899:1999 |
| .\" |
| .TH UNGETWC 3 2015-08-08 "GNU" "Linux Programmer's Manual" |
| .SH NAME |
| ungetwc \- push back a wide character onto a FILE stream |
| .SH SYNOPSIS |
| .nf |
| .B #include <wchar.h> |
| .PP |
| .BI "wint_t ungetwc(wint_t " wc ", FILE *" stream ); |
| .fi |
| .SH DESCRIPTION |
| The |
| .BR ungetwc () |
| function is the wide-character equivalent of the |
| .BR ungetc (3) |
| function. |
| It pushes back a wide character onto |
| .I stream |
| and returns it. |
| .PP |
| If |
| .I wc |
| is |
| .BR WEOF , |
| it returns |
| .BR WEOF . |
| If |
| .I wc |
| is an invalid wide character, |
| it sets |
| .I errno |
| to |
| .B EILSEQ |
| and returns |
| .BR WEOF . |
| .PP |
| If |
| .I wc |
| is a valid wide character, it is pushed back onto the stream |
| and thus becomes available for future wide-character read operations. |
| The file-position indicator is decremented by one or more. |
| The end-of-file |
| indicator is cleared. |
| The backing storage of the file is not affected. |
| .PP |
| Note: |
| .I wc |
| need not be the last wide-character read from the stream; |
| it can be any other valid wide character. |
| .PP |
| If the implementation supports multiple push-back operations in a row, the |
| pushed-back wide characters will be read in reverse order; however, only one |
| level of push-back is guaranteed. |
| .SH RETURN VALUE |
| The |
| .BR ungetwc () |
| function returns |
| .I wc |
| when successful, or |
| .B WEOF |
| upon |
| failure. |
| .SH ATTRIBUTES |
| For an explanation of the terms used in this section, see |
| .BR attributes (7). |
| .TS |
| allbox; |
| lb lb lb |
| l l l. |
| Interface Attribute Value |
| T{ |
| .BR ungetwc () |
| T} Thread safety MT-Safe |
| .TE |
| .SH CONFORMING TO |
| POSIX.1-2001, POSIX.1-2008, C99. |
| .SH NOTES |
| The behavior of |
| .BR ungetwc () |
| depends on the |
| .B LC_CTYPE |
| category of the |
| current locale. |
| .SH SEE ALSO |
| .BR fgetwc (3) |